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Purpose: To determine the contribution of germline pathogenic variants (PVs) in hereditary cancer testing panel genes to invasive lobular carcinoma (ILC) of the breast., Materials and Methods: The study included 2,999 women with ILC from a population-based cohort and 3,796 women with ILC undergoing clinical multigene panel testing (clinical cohort). Frequencies of germline PVs in breast cancer predisposition genes ( ATM , BARD1 , BRCA1 , BRCA2 , BRIP1 , CDH1 , CHEK2 , PALB2 , PTEN , RAD51C , RAD51D , and TP53 ) were compared between women with ILC and unaffected female controls and between women with ILC and infiltrating ductal carcinoma (IDC)., Results: The frequency of PVs in breast cancer predisposition genes among women with ILC was 6.5% in the clinical cohort and 5.2% in the population-based cohort. In case-control analysis, CDH1 and BRCA2 PVs were associated with high risks of ILC (odds ratio [OR] > 4) and CHEK2 , ATM , and PALB2 PVs were associated with moderate (OR = 2-4) risks. BRCA1 PVs and CHEK2 p.Ile157Thr were not associated with clinically relevant risks (OR < 2) of ILC. Compared with IDC, CDH1 PVs were > 10-fold enriched, whereas PVs in BRCA1 were substantially reduced in ILC., Conclusion: The study establishes that PVs in ATM , BRCA2 , CDH1 , CHEK2 , and PALB2 are associated with an increased risk of ILC, whereas BRCA1 PVs are not. The similar overall PV frequencies for ILC and IDC suggest that cancer histology should not influence the decision to proceed with genetic testing. Similar to IDC, multigene panel testing may be appropriate for women with ILC, but CDH1 should be specifically discussed because of low prevalence and gastric cancer risk., Competing Interests: Jeffrey N. WeitzelSpeakers' Bureau: AstraZeneca Celine M. VachonStock and Other Ownership Interests: Exact Sciences (I)Research Funding: GRAILPatents, Royalties, Other Intellectual Property: Breast Density softwareTravel, Accommodations, Expenses: GRAIL Allison W. KurianResearch Funding: Myriad GeneticsOther Relationship: Ambry Genetics, Color Genomics, GeneDx/BioReference, InVitae, Genentech Rachid KaramEmployment: Ambry GeneticsResearch Funding: Ambry GeneticsTravel, Accommodations, Expenses: Ambry Genetics Elizabeth ChaoEmployment: Ambry Genetics Amal YussufEmployment: Ambry Genetics Tina PesaranEmployment: Ambry Genetics/Konica Minolta Jill S. DolinskyEmployment: Ambry Genetics Holly LaDucaEmployment: Ambry GeneticsStock and Other Ownership Interests: Ambry Genetics Eric C. PolleyResearch Funding: GRAIL Susan M. DomchekHonoraria: AstraZeneca, Clovis Oncology, Bristol Myers SquibbResearch Funding: AstraZeneca, Clovis Oncology Fergus J. CouchConsulting or Advisory Role: AstraZenecaSpeakers' Bureau: Ambry Genetics, QiagenResearch Funding: GRAILTravel, Accommodations, Expenses: GRAIL, QiagenOther Relationship: Ambry GeneticsNo other potential conflicts of interest were reported.

Purpose: The prevalence of germline pathogenic variants (PVs) in established breast cancer predisposition genes in women in the general population over age 65 years is not well-defined. However, testing guidelines suggest that women diagnosed with breast cancer over age 65 years might have < 2.5% likelihood of a PV in a high-penetrance gene. This study aimed to establish the frequency of PVs and remaining risks of breast cancer for each gene in women over age 65 years., Methods: A total of 26,707 women over age 65 years from population-based studies (51.5% with breast cancer and 48.5% unaffected) were tested for PVs in germline predisposition gene. Frequencies of PVs and associations between PVs in each gene and breast cancer were assessed, and remaining lifetime breast cancer risks were estimated for non-Hispanic White women with PVs., Results: The frequency of PVs in predisposition genes was 3.18% for women with breast cancer and 1.48% for unaffected women over age 65 years. PVs in BRCA1 , BRCA2 , and PALB2 were found in 3.42% of women diagnosed with estrogen receptor (ER)-negative, 1.0% with ER-positive, and 3.01% with triple-negative breast cancer. Frequencies of PVs were lower among women with no first-degree relatives with breast cancer. PVs in CHEK2 , PALB2 , BRCA2 , and BRCA1 were associated with increased risks (odds ratio = 2.9-4.0) of breast cancer. Remaining lifetime risks of breast cancer were ≥ 15% for those with PVs in BRCA1 , BRCA2 , and PALB2 ., Conclusion: This study suggests that all women diagnosed with triple-negative breast cancer or ER-negative breast cancer should receive genetic testing and that women over age 65 years with BRCA1 and BRCA2 PVs and perhaps with PALB2 and CHEK2 PVs should be considered for magnetic resonance imaging screening., Competing Interests: Jeffrey N. WeitzelSpeakers' Bureau: AstraZeneca Amal YussufEmployment: Ambry Genetics Celine M. VachonStock and Other Ownership Interests: Exact SciencesResearch Funding: GRAILPatents, Royalties, Other Intellectual Property: Breast Density softwareTravel, Accommodations, Expenses: GRAIL Tina PesaranEmployment: Ambry Genetics/Konica MinoltaTravel, Accommodations, Expenses: Ambry Genetics/Konica Minolta Irene M. OngEmployment: Propeller HealthStock and Other Ownership Interests: AyrFlo Rachid KaramEmployment: Ambry GeneticsResearch Funding: Ambry GeneticsTravel, Accommodations, Expenses: Ambry Genetics Holly LaDucaEmployment: Ambry GeneticsStock and Other Ownership Interests: Ambry Genetics Jill S. DolinskyEmployment: Ambry Genetics Elizabeth ChaoEmployment: Ambry Genetics Eric C. PolleyResearch Funding: GRAIL Susan M. DomchekHonoraria: AstraZeneca, Clovis Oncology, Bristol Myers SquibbResearch Funding: AstraZeneca, Clovis OncologyOpen Payments Link: https://openpaymentsdata.cms.gov/physician/917904 Fergus J. CouchConsulting or Advisory Role: AstraZenecaSpeakers' Bureau: Ambry Genetics, QiagenResearch Funding: GRAILTravel, Accommodations, Expenses: GRAIL, QiagenOther Relationship: Ambry GeneticsNo other potential conflicts of interest were reported.

Background: Population-based estimates of the risk of breast cancer associated with germline pathogenic variants in cancer-predisposition genes are critically needed for risk assessment and management in women with inherited pathogenic variants., Methods: In a population-based case-control study, we performed sequencing using a custom multigene amplicon-based panel to identify germline pathogenic variants in 28 cancer-predisposition genes among 32,247 women with breast cancer (case patients) and 32,544 unaffected women (controls) from population-based studies in the Cancer Risk Estimates Related to Susceptibility (CARRIERS) consortium. Associations between pathogenic variants in each gene and the risk of breast cancer were assessed., Results: Pathogenic variants in 12 established breast cancer-predisposition genes were detected in 5.03% of case patients and in 1.63% of controls. Pathogenic variants in BRCA1 and BRCA2 were associated with a high risk of breast cancer, with odds ratios of 7.62 (95% confidence interval [CI], 5.33 to 11.27) and 5.23 (95% CI, 4.09 to 6.77), respectively. Pathogenic variants in PALB2 were associated with a moderate risk (odds ratio, 3.83; 95% CI, 2.68 to 5.63). Pathogenic variants in BARD1 , RAD51C , and RAD51D were associated with increased risks of estrogen receptor-negative breast cancer and triple-negative breast cancer, whereas pathogenic variants in ATM , CDH1 , and CHEK2 were associated with an increased risk of estrogen receptor-positive breast cancer. Pathogenic variants in 16 candidate breast cancer-predisposition genes, including the c.657&#95;661del5 founder pathogenic variant in NBN , were not associated with an increased risk of breast cancer., Conclusions: This study provides estimates of the prevalence and risk of breast cancer associated with pathogenic variants in known breast cancer-predisposition genes in the U.S. population. These estimates can inform cancer testing and screening and improve clinical management strategies for women in the general population with inherited pathogenic variants in these genes. (Funded by the National Institutes of Health and the Breast Cancer Research Foundation.)., (Copyright © 2021 Massachusetts Medical Society.)

The objective of this study was to estimate the lifetime risk of breast cancer in women with a BRCA1 or BRCA2 mutation with and without at least 1 first-degree relative with breast cancer. A total of 2835 women with a BRCA1 or BRCA2 mutation were followed. Age- and gene-specific breast cancer rates were calculated. The relative risks of breast cancer for subjects with a family history of breast cancer, compared to no family history were calculated. The mean age at baseline was 41.1 years, and they were followed for a mean of 6.0 years. The estimated penetrance of breast cancer to age 80 years was 60.8% for BRCA1 and 63.1% for BRCA2. For all BRCA carriers, the penetrance of breast cancer to age 80 for those with no first-degree relative with breast cancer was 60.4% and 63.3% for those with at least 1 first-degree relative with breast cancer. The risk of breast cancer for BRCA carriers with no first-degree relative with breast cancer is substantial, and as a result, clinical management for these women should be the same as those for women with an affected relative., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: Hypertension in pregnancy has been associated with decreased future risk of breast cancer in many but not all studies. In the Marin Women's Study, pregnancy-induced hypertension was shown to interact with the T allele of a functional IGF1R gene variant, rs2016347, to result in lower breast density, as well as decreased breast cancer risk. Our objective was to explore these findings in a larger sample of women from the California Teachers Study (CTS)., Methods: The CTS cohort consists of over 130,000 female educators. DNA was available from a nested case-control study, which included 2,030 non-Hispanic white women who developed breast cancer and 1,552 controls. The current study included all participants from the case-control group with a self-reported history of preeclampsia (80 cases/57 controls)., Results: Comparing TT to GG genotypes revealed adjusted odds ratios of 0.38 (CI 0.13, 1.14) for all invasive breast cancers, 0.26 (CI 0.07, 0.89) for hormone receptor-positive (HR+) breast cancers, 0.15 (CI 0.04, 0.56) for those with age at first birth (AFB) < 30, and 0.10 (CI 0.02, 0.49) for those with AFB < 30 and HR+ breast cancers. Trend analysis yielded p values of 0.09, 0.03, 0.005, and 0.004 respectively, suggesting a biological effect for each T allele., Conclusion: Study findings indicate that the T allele of IGF1R variant rs2016347 is associated with a significant reduction in breast cancer risk in women with a history of preeclampsia, most marked for HR+ breast cancer and in women with AFB < 30.

The major breast cancer suppressor proteins BRCA1 and BRCA2 play essential roles in homologous recombination (HR)-mediated DNA repair, which is thought to be critical for tumor suppression. The two BRCA proteins are linked by a third tumor suppressor, PALB2, in the HR pathway. While truncating mutations in these genes are generally pathogenic, interpretation of missense variants remains a challenge. To date, patient-derived missense variants that disrupt PALB2 binding have been identified in BRCA1 and BRCA2; however, there has not been sufficient evidence to prove their pathogenicity in humans, and no variants in PALB2 that disrupt either its BRCA1 or BRCA2 binding have been reported. Here we report on the identification of a novel PALB2 variant, c.104T>C (p.L35P), that segregates in a family with a strong history of breast cancer. Functional analyses showed that L35P abrogates the PALB2-BRCA1 interaction and completely disables its abilities to promote HR and confer resistance to platinum salts and PARP inhibitors. Whole-exome sequencing of a breast cancer from a c.104T>C carrier revealed a second, somatic, truncating mutation affecting PALB2, and the tumor displays hallmark genomic features of tumors with BRCA mutations and HR defects, cementing the pathogenicity of L35P. Parallel analyses of other germline variants in the PALB2 N-terminal BRCA1-binding domain identified multiple variants that affect HR function to varying degrees, suggesting their possible contribution to cancer development. Our findings establish L35P as the first pathogenic missense mutation in PALB2 and directly demonstrate the requirement of the PALB2-BRCA1 interaction for breast cancer suppression.

Background: The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study., Methods: We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2 c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant., Results: For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p=7.1×10 -5 ), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p=6.9×10 -8 ) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p=0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p≤0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p=0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p=0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants., Conclusions: This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important., Competing Interests: Conflicts of Interest: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

The 10q26 locus in the second intron of FGFR2 is the locus most strongly associated with estrogen-receptor-positive breast cancer in genome-wide association studies. We conducted fine-scale mapping in case-control studies genotyped with a custom chip (iCOGS), comprising 41 studies (n = 89,050) of European ancestry, 9 Asian ancestry studies (n = 13,983), and 2 African ancestry studies (n = 2,028) from the Breast Cancer Association Consortium. We identified three statistically independent risk signals within the locus. Within risk signals 1 and 3, genetic analysis identified five and two variants, respectively, highly correlated with the most strongly associated SNPs. By using a combination of genetic fine mapping, data on DNase hypersensitivity, and electrophoretic mobility shift assays to study protein-DNA binding, we identified rs35054928, rs2981578, and rs45631563 as putative functional SNPs. Chromatin immunoprecipitation showed that FOXA1 preferentially bound to the risk-associated allele (C) of rs2981578 and was able to recruit ERα to this site in an allele-specific manner, whereas E2F1 preferentially bound the risk variant of rs35054928. The risk alleles were preferentially found in open chromatin and bound by Ser5 phosphorylated RNA polymerase II, suggesting that the risk alleles are associated with changes in transcription. Chromatin conformation capture demonstrated that the risk region was able to interact with the promoter of FGFR2, the likely target gene of this risk region. A role for FOXA1 in mediating breast cancer susceptibility at this locus is consistent with the finding that the FGFR2 risk locus primarily predisposes to estrogen-receptor-positive disease., (Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

The objective is to estimate the risk of breast cancer in women who carry a deleterious BRCA1 or BRCA2 mutation, according to parental origin of mutation. We conducted a cohort study of women with a BRCA1 mutation (n = 1523) or BRCA2 mutation (n = 369) who had not been diagnosed with breast or ovarian cancer. For each woman, the pedigree was reviewed and the origin of the mutation was assigned as probable paternal or maternal. The hazard ratio (HR) for developing breast cancer in the follow-up period was estimated for women with a paternal mutation compared to a maternal mutation. The risk of breast cancer was modestly higher in women with a paternal BRCA1 mutation compared to women with a maternal BRCA1 mutation (HR = 1.46; 95% CI = 0.99-2.16) but the difference was not significant (p = 0.06). The parental mutation origin did not affect the risk in women with a BRCA2 mutation. Our results are consistent with the hypothesis that there is an increased risk of breast cancer among women with a paternally inherited BRCA1 mutation compared to a maternally inherited mutation. However, the data are not sufficiently compelling to justify different screening recommendations for the two subgroups., (© 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: To evaluate the effect of the cumulative number of ovulatory cycles and its contributing components on the risk of breast cancer among BRCA mutation carriers., Methods: We conducted a matched case-control study on 2,854 pairs of women with a BRCA1 or BRCA2 mutation. Conditional logistic regression was used to estimate the association between the number of ovulatory cycles and various exposures and the risk of breast cancer. Information from a subset of these women enrolled in a prospective cohort study was used to calculate age-specific breast cancer rates., Results: The annual risk of breast cancer decreased with the number of ovulatory cycles experienced (ρ = -0.69; P = 0.03). Age at menarche and duration of breastfeeding were inversely related with risk of breast cancer among BRCA1 (P(trend) < 0.0001) but not among BRCA2 (P(trend) ≥ 0.28) mutation carriers. The reduction in breast cancer risk associated with surgical menopause [OR, 0.52; 95% confidence interval (CI), 0.40-0.66; P(trend) < 0.0001] was greater than that associated with natural menopause (OR, 0.81; 95% CI, 0.62-1.07; P(trend) = 0.14). There was a highly significant reduction in breast cancer risk among women who had an oophorectomy after natural menopause (OR, 0.13; 95% CI, 0.02-0.54; P = 0.006)., Conclusions: These data challenge the hypothesis that breast cancer risk can be predicted by the lifetime number of ovulatory cycles in women with a BRCA mutation. Both pre- and postmenopausal oophorectomy protect against breast cancer., Impact: Understanding the basis for the protective effect of oophorectomy has important implications for chemoprevention., (©2012 AACR)

An exome-sequencing study of families with multiple breast-cancer-affected individuals identified two families with XRCC2 mutations, one with a protein-truncating mutation and one with a probably deleterious missense mutation. We performed a population-based case-control mutation-screening study that identified six probably pathogenic coding variants in 1,308 cases with early-onset breast cancer and no variants in 1,120 controls (the severity grading was p < 0.02). We also performed additional mutation screening in 689 multiple-case families. We identified ten breast-cancer-affected families with protein-truncating or probably deleterious rare missense variants in XRCC2. Our identification of XRCC2 as a breast cancer susceptibility gene thus increases the proportion of breast cancers that are associated with homologous recombination-DNA-repair dysfunction and Fanconi anemia and could therefore benefit from specific targeted treatments such as PARP (poly ADP ribose polymerase) inhibitors. This study demonstrates the power of massively parallel sequencing for discovering susceptibility genes for common, complex diseases., (Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Background: Hyperinsulinemia and the metabolic syndrome are both risk factors for breast cancer. It is not clear if diabetes is associated with the risk of breast cancer in women with a BRCA1 or BRCA2 mutation., Methods: The authors reviewed the medical histories of 6052 women with a BRCA1 or BRCA2 mutation, half of whom had been diagnosed with breast cancer. They estimated the odds ratio for breast cancer, given a self-report of diabetes. They then estimated the hazard ratio for a new diagnosis of diabetes associated with a history of breast cancer., Results: There was no excess of diabetes in the period before the diagnosis of breast cancer, compared with controls with no diagnosis of breast cancer. The risk of diabetes was doubled among BRCA carriers in the 15-year period after the diagnosis of breast cancer (relative risk, 2.0; 95% confidence interval [CI], 1.4-2.8; P = .0001), compared with carriers without cancer. The risk was particularly high for women with a body mass index (BMI) >25.0 kg/m(2) (odds ratio, 5.8; 95% CI, 4.0-8.6; P = .0001)., Conclusions: After a diagnosis of breast cancer, women with a BRCA1 or BRCA2 mutation face a 2-fold increase in the risk of diabetes, which is exacerbated by a high BMI., (Copyright © 2010 American Cancer Society.)

Background: Inherited BRCA1 and BRCA2 (BRCA1/2) mutations confer elevated breast cancer risk. Knowledge of factors that can improve breast cancer risk assessment in BRCA1/2 mutation carriers may improve personalized cancer prevention strategies., Methods: A cohort of 5,546 BRCA1 and 2,865 BRCA2 mutation carriers was used to evaluate risk of breast cancer associated with BARD1 Cys557Ser. In a second nonindependent cohort of 1,537 of BRCA1 and 839 BRCA2 mutation carriers, BARD1 haplotypes were also evaluated., Results: The BARD1 Cys557Ser variant was not significantly associated with risk of breast cancer from single SNP analysis, with a pooled effect estimate of 0.90 (95% CI: 0.71-1.15) in BRCA1 carriers and 0.87 (95% CI: 0.59-1.29) in BRCA2 carriers. Further analysis of haplotypes at BARD1 also revealed no evidence that additional common genetic variation not captured by Cys557Ser was associated with breast cancer risk., Conclusion: Evidence to date does not support a role for BARD1 variation, including the Cy557Ser variant, as a modifier of risk in BRCA1/2 mutation carriers., Impact: Interactors of BRCA1/2 have been implicated as modifiers of BRCA1/2-associated cancer risk. Our finding that BARD1 does not contribute to this risk modification may focus research on other genes that do modify BRCA1/2-associated cancer risk., (©2011 AACR.)

Women who carry a deleterious mutation in BRCA1 or BRCA2 have high lifetime risks of breast and ovarian cancers. However, the influence of a family history of these cancers on these risks in women with BRCA mutations is unclear. We calculated cancer incidence rates for a multinational cohort comprising 3011 women with BRCA1 or BRCA2 mutations who were followed up for a mean of 3.9 years, during which time 243 incident breast or ovarian cancers were recorded. The 10-year cumulative risks of breast cancer were 18.1% (95% confidence interval [CI] = 13.3% to 22.8%) for women with a BRCA1 mutation and 15.2% (95% CI = 9.1% to 21.2%) for women with a BRCA2 mutation. Among women with a BRCA1 mutation, the risk of breast cancer increased by 1.2-fold for each first-degree relative with breast cancer before age 50 years (hazard ratio [HR] = 1.21; 95% confidence interval [CI] = 0.94 to 1.57) and the risk of ovarian cancer increased by 1.6 fold for each first- or second-degree relative with ovarian cancer (HR = 1.61; 95% CI = 1.21 to 2.14). Among women with a BRCA2 mutation, the risk of breast cancer increased by 1.7-fold for each first-degree relative younger than 50 years with breast cancer (HR = 1.67; 95% CI = 1.04 to 2.07).

Background: We investigated the association between hypertension, antihypertensive (AH) medication use, and breast cancer in a large prospective study, the California Teachers Study (CTS)., Methods: Information on history of hypertension and lifetime regular use of AH medications was collected from 114,549 women in 1995-1996. Among them, 4,151 invasive breast cancers were diagnosed between 1995 and 2006. Additional information on AH use was collected from 73,742 women in 2000-2001, and 1,714 of these women were subsequently diagnosed with breast cancer. Cox proportional hazards regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) for breast cancer., Results: Use of AH medication for ≥5 years, when compared with no use, was associated with a modest increased risk of invasive breast cancer (RR = 1.18, 95%CI 1.02-1.36). This increased risk appeared to be confined to estrogen receptor (ER)-positive tumors (RR = 1.21, 95%CI 1.03-1.43) and pre-/peri-menopausal women (RR = 1.58, 95%CI 1.11-2.25)., Conclusions: Increased risk of invasive breast cancer was observed for long-term (≥5 years) AH use, and this appeared to be confined to ER + breast cancer and younger women.

Introduction: Long-term physical activity is associated with lower breast cancer risk. Little information exists on its association with subsequent survival., Methods: California Teachers Study cohort members provided information in 1995-1996 on long-term (high school through age 54 years) and recent (past 3 years) participation in moderate and strenuous recreational physical activities. The 3,539 women diagnosed with invasive breast cancer after cohort entry and through December 31, 2004, were followed through December 31, 2005. Of these, 460 women died, 221 from breast cancer. Moderate and strenuous physical activities were combined into low (3.0 h/wk/y), or high activity (>3.0 h/wk/y of either activity type). Multivariable relative risks (RR) and 95% confidence intervals (95% CI) for mortality were estimated using Cox proportional hazards methods, adjusting for race/ethnicity, estrogen receptor status, disease stage, and baseline information on comorbidities, body mass index, and caloric intake., Results: Women with high or intermediate levels of long-term physical activity had lower risk of breast cancer death (RR, 0.53; 95% CI, 0.35-0.80; and RR, 0.65; 95% CI, 0.45-0.93, respectively) than women with low activity levels. These associations were consistent across estrogen receptor status and disease stage, but were confined to overweight women. Deaths due to causes other than breast cancer were related only to recent activity., Conclusions: Consistent long-term participation in physical activity before breast cancer diagnosis may lower risk of breast cancer death, providing further justification for public health strategies to increase physical activity throughout the lifespan.

Among women with a mutation in BRCA1 or BRCA2, the risk of breast cancer is high, but it may be modified by exogenous and endogenous factors. There is concern that exposure to carcinogens in cigarette smoke may increase the risk of cancer in mutation carriers. We conducted a matched case-control study of 2,538 cases of breast cancer among women with a BRCA1 (n = 1,920) or a BRCA2 (n = 618) mutation. One non-affected mutation carrier control was selected for each case, matched on mutation, country of birth, and year of birth. Odds ratios were calculated using conditional logistic regression, adjusted for oral contraceptive use and parity. Ever-smoking was not associated with an increased breast cancer risk among BRCA1 carriers (OR = 1.09; 95% CI 0.95-1.24) or among BRCA2 carriers (OR = 0.81; 95% CI 0.63-1.05). The result did not differ when cases were restricted to women who completed the questionnaire within two years of diagnosis. A modest, but significant increase in risk was seen among BRCA1 carriers with a past history of smoking (OR = 1.27; 95% CI 1.06-1.50), but not among current smokers (OR = 0.95; 0.81-1.12). There appears to be no increase in the risk of breast cancer associated with current smoking in BRCA1 or BRCA2 carriers. There is a possibility of an increased risk of breast cancer among BRCA1 carriers associated with past smoking. There may be different effects of carcinogens in BRCA mutation carriers, depending upon the timing of exposure.

Background: Early studies of incomplete pregnancy and development of breast cancer suggested that induced abortion might increase risk. Several large prospective studies, which eliminate recall bias, did not detect associations, but this relationship continues to be debated., Study Design: To further inform this important question, we examined invasive breast cancer as it relates to incomplete pregnancy, including total number of induced abortions, age at first induced abortion and total number of miscarriages among women participating in the ongoing California Teachers Study (CTS) cohort. Incomplete pregnancy was self-reported on the CTS baseline questionnaire in 1995-1996. Incident breast cancers were ascertained in 3324 women through 2004 via linkage with the California Cancer Registry., Results: Using Cox multivariable regression, we found no statistically significant association between any measure of incomplete pregnancy and breast cancer risk among nulliparous or parous women., Conclusion: These results provide strong evidence that there is no relationship between incomplete pregnancy and breast cancer risk.

We studied the feasibility of a novel approach to localize breast cancer susceptibility genes, using a low-density genome-wide panel of single-nucleotide polymorphisms and taking advantage of large regions of linkage disequilibrium (LD) flanking Jewish disease genes in high-risk cases. With Affymetrix GeneChip arrays, we genotyped 8,576 polymorphisms in three sets of Ashkenazi Jewish breast cancer cases: a "validation" set of 27 breast cancer cases, all of whom carried the BRCA2*6174delT founder mutation; a "field" set of 19 breast cancer cases from male breast cancer kindreds, which simulated conditions for finding new genes; and a "test" set of 57 probands from breast cancer kindreds (4 or more cases/kindred), in which mutations in BRCA1 and BRCA2 had been excluded. To identify associations, we compared the frequency of genotypes and haplotypes in cases vs. controls by the Fisher's exact test and a maximum likelihood ratio test. In the "validation" set, we demonstrated the presence of a region of linkage disequilibrium on BRCA2*6174delT chromosomes that spanned over 5 million bases. In the "field" set, we showed that this large region of linkage disequilibrium flanking BRCA2 was detectable despite the presence of heterogeneity in the sample set. Finally, in the "test" set, at least three regions of interest emerged that could contain novel breast cancer genes, one of which had been identified previously by linkage analysis. While these results demonstrate the feasibility of genome-wide association strategies, further application of this approach will critically depend on optimizing the density and distribution of SNPs and the size and type of study design., (Copyright 2005 Wiley-Liss, Inc.)

Unlabelled: Approximately 12% of the U.S. population is Hispanic, with the majority residing in urban centers such as Los Angeles. The prevalence of BRCA mutations among high-risk Hispanic families is unknown., Methods: One hundred and ten unrelated probands of Hispanic origin, with a personal or family history of breast and/or ovarian cancer, presented for genetic cancer risk assessment, were enrolled in an Institutional Review Board-approved registry and underwent BRCA testing. Haplotype analyses were done if BRCA mutations were observed in two or more unrelated probands., Results: Mean age at diagnosis was 37 years (range = 23-59) for the 89 (81%) probands with invasive breast cancer. Overall, 34 (30.9%) had deleterious mutations (25 in BRCA1, 9 in BRCA2), 25 (22.7%) had one or more unclassified variants, and 51 (46.4%) had negative results. The mean pretest mutation probability using the Couch model, Myriad model, and BRCAPro was 19.6% (range = 4-77%). The combined average mutation probability was 32.8% for carriers, 15.5% for noncarriers, and 12.9% for variant carriers (P < 0.0001). The most common deleterious mutation was 185delAG (4 of 34, 11.8%). The Hispanic 185delAG carrier families share the same haplotype from D17s1320 through BRCA1, as do two reference Ashkenazi Jewish families. Haplotype analyses of additional recurrent BRCA1 mutations [IVS5+1G>A (n=2),S955X (n = 3), R1443X (n = 3), and 2552delC (n = 2)] also suggest founder effects, with four of six mutations seen almost exclusively in families with Latin American/Caribbean or Spanish ancestry., Conclusion: This is the largest study to date of high-risk Hispanic families in the United States. Six recurrent mutations accounted for 47% (16 of 34) of the deleterious mutations in this cohort. The BRCA1185delAG mutation was prevalent (3.6%) in this clinic-based cohort of predominantly Mexican descent, and shared the Ashkenazi Jewish founder haplotype.

Background: Several studies have reported that the risk of breast cancer decreases with increasing duration of breast-feeding. Whether breast-feeding is associated with a reduced risk of hereditary breast cancer in women who carry deleterious BRCA1 and BRCA2 mutations is currently unknown., Methods: We conducted a case-control study of women with deleterious mutations in either the BRCA1 or the BRCA2 gene. Study participants, drawn from an international cohort, were matched on the basis of BRCA mutation (BRCA1 [n = 685] or BRCA2 [n = 280]), year of birth (+/-2 years), and country of residence. The study involved 965 case subjects diagnosed with breast cancer and 965 control subjects who had no history of breast or ovarian cancer. Information on pregnancies and breast-feeding practices was derived from a questionnaire administered to the women during the course of genetic counseling. Conditional logistic regression analyses were used to estimate odds ratios (ORs) for the risk of breast cancer. All statistical tests were two-sided., Results: Among women with BRCA1 mutations, the mean total duration of breast-feeding was statistically significantly shorter for case subjects than for control subjects (6.0 versus 8.7 months, respectively; mean difference = 2.7 months, 95% confidence interval [CI] = 1.4 to 4.0; P<.001). The total duration of breast-feeding was associated with a reduced risk of breast cancer (for each month of breast-feeding, OR = 0.98, 95% CI = 0.97 to 0.99; P(trend)<.001). Women with BRCA1 mutations who breast-fed for more than 1 year were less likely to have breast cancer than those who never breast-fed (OR = 0.55, 95% CI = 0.38 to 0.80; P =.001), although no such association was seen for BRCA2 (OR = 0.95, 95% CI = 0.56 to 1.59; P =.83)., Conclusions: Women with deleterious BRCA1 mutations who breast-fed for a cumulative total of more than 1 year had a statistically significantly reduced risk of breast cancer.

Background: This study assessed counseling and testing needs from the perspective of adult members of a large African-American kindred with a BRCA1 mutation., Methods: Interviews were conducted with 95 male and female kindred members to elicit information on sociodemographics, attitudes toward health care providers, breast cancer screening behaviors, and religious/spiritual beliefs, as well as to evaluate psychological distress, beliefs, knowledge, and attitudes related to genetic testing., Results: Knowledge about breast and ovarian cancer genetics was limited. Adherence to screening recommendations was low among females with no personal breast or ovarian cancer history. The majority (67%) wished to discuss risk factors with a health care provider. Most participants (82%) indicated that they would have a genetic test if it were available. Significant predictors of intent to undergo testing were having at least one first-degree relative with breast and/or ovarian cancer (OR = 5.1; 95% CI = 1.2-20.9) and perceived risk of being a gene carrier > or =50% (OR = 64.3; 95% CI = 5.1-803.9) or reporting that they did not know their risk of being a gene carrier (OR = 10.9; 95% CI = 2.1-57.7). Cited barriers to testing included cost and availability., Conclusion: There is a high interest level in genetic testing despite limited knowledge about cancer genetics among these high-risk African Americans. Our study provides information for designing a genetic education and counseling intervention for this and similar families., (Copyright 2001 American Health Foundation and Elsevier Science.)

Germline mutations in the BRCA1 gene are causative for a variable number of hereditary breast/ovarian cancers. The data presented in this study are based on genetic analysis of the BRCA1 gene in 49 DNA samples from breast cancer patients with a positive family history. A combination of manual direct DNA sequencing and SSCP analysis was used to screen the entire coding region of BRCA1. Overall 13 variants were detected which included 5 missense mutations, 3 polymorphisms and 5 intronic changes. Further genetic analysis of the 13 variants was carried out using 50 control DNA samples. Our results showed that 12 out of the 13 variants detected in the DNA of the patients group, were also present in the control group. It appears that the Greek Cypriot families studied so far have an unexpectebly low frequency of deleterious mutations in the BRCA1 gene. This is the first report on BRCA1 mutation analysis in Cyprus.

Women who have inherited a germ-line mutation in the BRCA1 or BRCA2 (BRCA1/2) genes have a greatly increased risk of developing breast cancer compared with the general population. However, there is also substantial interindividual variability in the occurrence of breast cancer among BRCA1/2 mutation carriers. We hypothesize that genes involved in endocrine signaling may modify the BRCA1/2-associated age-specific breast cancer penetrance. We studied the effect of alleles at the AIB1 gene using a matched case-control sample of 448 women with germ-line BRCA1/2 mutations. We found that these women were at significantly higher breast cancer risk if they carried alleles with at least 28 or 29 polyglutamine repeats at AIB1, compared with women who carried alleles with fewer polyglutamine repeats [odds ratio (OR), 1.59; 95% confidence interval (CI), 1.03-2.47 and OR, 2.85; 95% CI, 1.64-4.96, respectively]. Late age at first live birth and nulliparity have been associated with increased breast cancer risk. We observed increases in BRCA1/2-associated breast cancer risk in women who were either nulliparous or had their first live birth after age 30 (OR, 3.06; 95% CI, 1.52-6.16). Women were at significantly increased risk if they were nulliparous or had a late age at first live birth and had AIB1 alleles no shorter than 28 or 29 or more AIB1 polyglutamine repeats (OR, 4.62; 95% CI, 2.02-10.56 and OR, 6.97; 95% CI, 1.71-28.43, respectively) than women with none of these risk factors. Our results support the hypothesis that pathways involving endocrine signaling, as measured through AIB1 genotype and reproductive history, may have a substantial effect on BRCA1/2-associated breast cancer risk.

Purpose: Hodgkin's disease patients who receive mantle irradiation have an age-dependent increased risk of developing breast cancer. To determine if genetic factors predispose these patients to develop breast cancer, we evaluated breast cancer specimens for loss of heterozygosity (LOH) at regions where BRCA1 and BRCA2, two breast cancer tumor suppressor genes, are located. We also evaluated whether breast cancers in patients who were previously treated with radiation have a more aggressive phenotype, and whether the clinical course differed from a sporadic group of breast cancer patients., Methods and Materials: All females with Hodgkin's disease who were subsequently diagnosed with breast cancer and for whom tissue blocks were available were included. Using a case-control design, case patients (previously treated with radiation therapy) were matched with sporadic control breast cancer patients for age, breast cancer stage, and date of breast cancer diagnosis. After microdissection of tumor and normal tissue from paraffin-embedded tissue blocks, DNA was extracted and samples were examined for LOH at chromosomal segments encompassing BRCA1 and BRCA2. Breast cancer specimens were also evaluated in a blinded fashion for tumor grade and immunoreactivity to estrogen and progesterone receptors, p53, her2-neu, and topoisomerase II alpha. Comparisons were made between the case and control populations using chi2 analysis, and a paired Student's t test. Survival differences were evaluated using a log-rank test., Results: From January 1960 to December 1983, 917 patients were diagnosed with Hodgkin's disease. Twelve patients were subsequently diagnosed with breast cancer and tissue blocks were available on 10 cases. No statistical difference was observed between the case and control populations for LOH at BRCA1 or BRCA2. In the Hodgkin's disease group, LOH was observed in 30% of tumors at BRCA1 and 10% of tumors at BRCA2 vs. 10% and 0% of tumors in the control group at BRCA1 and BRCA2, respectively. Breast tumors from patients who received radiation therapy for Hodgkin's disease displayed greater nuclear pleomorphism (p < 0.02), and an increase in topoisomerase II alpha expression (p < 0.05) vs. the control population. Five of 10 patients were pregnant at the time of their Hodgkin's treatment, and those patients had a shorter time interval to the development of breast cancer compared with the patients who were not pregnant (12.4 years compared with 18.6 years). There was no significant difference in disease-free survival; however, overall survival was inferior in the population previously treated with radiation therapy for Hodgkin's disease (p = 0.01). 80% of patients with a previous Hodgkin's diagnosis died of breast cancer or treatment related effects vs. 30% in the control group., Conclusion: We were unable to find statistical evidence for LOH at BRCA1 and BRCA2 in breast cancers from patients previously irradiated for Hodgkin's disease. Breast cancer diagnosed after mantle irradiation may be more biologically aggressive based on the greater nuclear pleomorphism and increase in topoisomerase II alpha staining. This did not translate into a statistical difference in breast cancer disease-free survival; however, overall survival was significantly inferior in the Hodgkin's disease patients.

Background: Women with a mutation in BRCA1 or BRCA2 have a high risk of developing breast cancer and of contralateral cancer after the initial diagnosis of breast cancer. Tamoxifen protects against contralateral breast cancer in the general population, but whether it protects against contralateral breast cancer in BRCA1 or BRCA2 mutation carriers is not known., Methods: We compared 209 women with bilateral breast cancer and BRCA1 or BRCA2 mutation (bilateral-disease cases), with 384 women with unilateral disease and BRCA1 or BRCA2 mutation (controls) in a matched case-control study. Age and age at diagnosis of breast cancer (range 24-74 years) were much the same in bilateral-disease cases and controls, and both groups had been followed up for the same time for a second primary breast cancer. History of tamoxifen use for first breast cancer was obtained by interview, or by self-administered questionnaire., Findings: The multivariate odds ratio for contralateral breast cancer associated with tamoxifen use was 0.50 (95% CI 0.28-0.89). Tamoxifen protected against contralateral breast cancer for carriers of BRCA1 mutations (odds ratio 0.38, 95% CI 0.19-0.74) and for those with BRCA2 mutations (0.63, 0.20-1.50). In women who used tamoxifen for 2-4 years, the risk of contralateral breast cancer was reduced by 75%. A reduction in risk of contralateral cancer was also seen with oophorectomy (0.42, 0.22-0.83) and with chemotherapy (0-40, 0.26-0.60)., Interpretation: Tamoxifen use reduces the risk of contralateral breast cancer in women with pathogenic mutations in the BRCA1 or BRCA2 gene. The protective effect of tamoxifen seems independent of that of oophorectomy.

Several recent studies indicate that the majority of families with five or fewer cases of breast cancer and no cases of ovarian cancer are not due to BRCA1 or BRCA2. It has been proposed that a further breast cancer susceptibility gene that may account for some of these families is located on chromosome 8p12-p22. We have identified 31 site-specific breast cancer families that have a greater than 80% posterior probability of being due to genes other than BRCA1 or BRCA2. These families have been examined for linkage to 8p12-p22 using markers flanking the putative location of the gene. The overall multi-point LOD score is strongly negative across the whole 44 cM. The individual multi-point LOD score is negative in 23 families and only exceeds 0.5 in a single family (with a multi-point LOD score of 1.22). The maximum heterogeneity LOD score was 0.03 at marker D8S136 with estimated proportion linked (alpha) of 3% (95% CI 0 - 30%). These data do not lend support to the hypothesis that chromosome 8p12-p22 harbours a familial breast cancer susceptibility gene. Oncogene (2000) 19, 4170 - 4173

Breast cancers arising in carriers of mutations in the breast cancer susceptibility genes, BRCA1 and BRCA2, differ histologically from each other and from breast cancers unselected for a family history. However, a substantial proportion of families with multiple cases of breast cancer is not attributable to these two genes (non-BRCA1/2 families). We have now characterized the pathology of 82 breast cancers from non-BRCA1/2 families. Breast cancers in non-BRCA1/2 families were of lower grade (P = 0.0018), showed fewer mitoses (P < 0.0001), less nuclear pleomorphism (P = 0.0014), less lymphocytic infiltrate (P < 0.0001), a lesser extent of the tumor with a continuous pushing margin (P = 0.004), a lesser extent of the tumor composed of solid sheets of cells (P = 0.0047), less necrosis (P = 0.002), and wereparison with BRCA2 tumors, non-BRCA1/2 tumors were lower grade (P = 0.017) and exhibited less pleomorphism (P = 0.01) and more tubule formation (P = 0.05). In comparison with control breast cancers unselected for a family history of the disease, non-BRCA1/2 tumors were of significantly lower grade (P = 0.001), showed less pleomorphism (P = 0.0002), and had a lower mitotic count (P = 0.003). The results indicate that non-BRCA1/2 breast cancers differ histologically from both BRCA1 and BRCA2 breast cancers and are overall of lower grade. They also suggest that non-BRCA1/2 breast cancers differ from nonfamilial breast cancers, but these differences may be attributable to various types of bias.

Genetic testing for mutations in BRCA1 and BRCA2, two genes predisposing to breast and ovarian cancers, is available to women with a relevant family history. The aim of this study was to estimate the positive and negative predictive value of clinical sequence analysis of these genes. A reference graph showing positive and negative predictive values over a range of pre-test risk was derived, taking into account the sensitivity and specificity of a full-sequence analysis test. High positive and negative predictive values were found for women with pre-test risk between 4% and 40%, a range of risk commonly seen in clinical testing. The predictive value of full sequence and single-site analysis of BRCA1 and BRCA2, therefore, compares favorably with other diagnostic medical tests. Our results provide a numerical estimate of the predictive value of BRCA testing, and as such, provide a valuable tool to healthcare providers and families as they interpret BRCA1 and BRCA2 test results.

Numerous founder mutations have been reported in BRCA1 and BRCA2. For genetic screening of a population with a founder mutation, testing can be targeted to the mutation, allowing for a more rapid and less expensive test. In addition, more precise estimates of the prior probability of carrying a mutation and of the likelihood of a mutation carrier developing cancer should be possible. For a given founder mutation a large number of carriers are available, so that focused scientific studies of penetrance, expression, and genetic and environmental modifiers of risk can be performed. Finally, founder populations may be a powerful resource to localize additional breast cancer susceptibility loci, because of the reduction in locus heterogeneity.

Ethnic differences in cancer incidence and mortality exist and are probably the result of genetic and epidemiological risk factors. Genetic differences caused by founder mutations are reviewed, with special emphasis on mutations in BRCA1 and BRCA2. Germline mutations in cancer susceptibility genes have been identified in individuals of all races and ethnic groups. Differences among ethnic groups for cancer risks have been recognized, and a proportion of the differences may be the result of founder mutations within these genes. The BRCA2 999del5 mutation in Iceland and the three BRCA1 and BRCA2 mutations in Ashkenazic Jews have been well characterized and were easy to study because the patient population and anonymous samples were readily available and ethnicity was known. Mutations in BRCA1 and BRCA2 probably account for approximately 3 to 10% of breast cancer in the general population and a much higher proportion in those with a strong family history of breast and ovarian cancers and in those of Ashkenazic Jewish descent. However, no overall increased risk of breast or ovarian cancers exists among Ashkenazic Jewish women compared with non-Jewish Caucasians. Some ethnic variation in cancer risk may be explained by founder mutations identified in cancer-predisposing genes. Knowledge acquired by studying the effect of a single mutation in a well defined population may be applied to larger, more heterogeneous populations. Individuals from all racial and ethnic groups carry deleterious mutations. Mutations are simply easier to find and characterize when identified in a specific ethnic group.

Background: The availability of genetic testing for inherited mutations in the BRCA1 gene provides potentially valuable information to women at high risk of breast or ovarian cancer; however, carriers of BRCA1 mutations have few clinical management options to reduce their cancer risk. Decreases in ovarian hormone exposure following bilateral prophylactic oophorectomy (i.e., surgical removal of the ovaries) may alter cancer risk in BRCA1 mutation carriers. This study was undertaken to evaluate whether bilateral prophylactic oophorectomy is associated with a reduction in breast cancer risk in BRCA1 mutation carriers., Methods: We studied a cohort of women with disease-associated germline BRCA1 mutations who were assembled from five North American centers. Surgery subjects (n = 43) included women with BRCA1 mutations who underwent bilateral prophylactic oophorectomy but had no history of breast or ovarian cancer and had not had a prophylactic mastectomy. Control subjects included women with BRCA1 mutations who had no history of oophorectomy and no history of breast or ovarian cancer (n = 79). Control subjects were matched to the surgery subjects according to center and year of birth., Results: We found a statistically significant reduction in breast cancer risk after bilateral prophylactic oophorectomy, with an adjusted hazard ratio (HR) of 0.53 (95% confidence interval [CI] = 0.33-0.84). This risk reduction was even greater in women who were followed 5-10 (HR = 0. 28; 95% CI = 0.08-0.94) or at least 10 (HR = 0.33; 95% CI = 0.12-0.91) years after surgery. Use of hormone replacement therapy did not negate the reduction in breast cancer risk after surgery., Conclusions: Bilateral prophylactic oophorectomy is associated with a reduced breast cancer risk in women who carry a BRCA1 mutation. The likely mechanism is reduction of ovarian hormone exposure. These findings have implications for the management of breast cancer risk in women who carry BRCA1 mutations.

Compared with the general population, women who have inherited a germline mutation in the BRCA1 gene have a greatly increased risk of developing breast cancer. However, there is also substantial interindividual variability in the occurrence of breast cancer among BRCA1 mutation carriers. We hypothesize that other genes, particularly those involved in endocrine signaling, may modify the BRCA1-associated age-specific breast cancer risk. We studied the effect of the CAG repeat-length polymorphism found in exon 1 of the androgen-receptor (AR) gene (AR-CAG). AR alleles containing longer CAG repeat lengths are associated with a decreased ability to activate androgen-responsive genes. Using a sample of women who inherited germline BRCA1 mutations, we compared AR-CAG repeat length in 165 women with and 139 women without breast cancer. We found that women were at significantly increased risk of breast cancer if they carried at least one AR allele with >/=28 CAG repeats. Women who carried an AR-CAG allele of >/=28, >/=29, or >/=30 repeats were given a diagnosis 0.8, 1.8, or 6.3 years earlier than women who did not carry at least one such allele. All 11 women in our sample who carried at least one AR-CAG allele with >/=29 repeats had breast cancer. Our results support the hypothesis that age at breast cancer diagnosis is earlier among BRCA1 mutation carriers who carry very long AR-CAG repeats. These results suggest that pathways involving androgen signaling may affect the risk of BRCA1-associated breast cancer.

Patients with hereditary breast cancer (HBC) present at a young age with breast cancers that show adverse pathological characteristics such as high nuclear grade, negative hormone receptor status, and high proliferation indices. Surprisingly, the clinical course has been reported to be comparable or improved compared with patients with nonhereditary breast cancer (non-HBC). To determine whether there are any molecular markers that might help explain this paradox between pathologically aggressive neoplasms in patients with HBC and the lack of extreme clinically aggressive disease, we studied several molecular parameters in a group of 34 breast cancer patients with mutations in either the BRCA1 or BRCA2 tumor suppressor genes and compared them with a group of 20 breast cancer patients with non-HBC. In general, patients with HBC had tumors that were of higher nuclear grade, contained a higher population of proliferating cells, showed increased expression of DNA topoisomerase II-alpha (topo II-alpha), lacked hormone receptors, and were more likely to show immunopositivity for the p53 tumor suppressor gene. Additionally, tumors from patients with HBC showed a decreased angiogenesis compared with controls. The decreased angiogenesis and the elevated expression of topo II-alpha (an anticancer drug target) may, in part, explain the lack of correlation between clinical course and histological characteristics in patients with HBC.

Background: We have previously demonstrated that breast cancers associated with inherited BRCA1 and BRCA2 gene mutations differ from each other in their histopathologic appearances and that each of these types differs from breast cancers in patients unselected for family history (i.e., sporadic cancers). We have now conducted a more detailed examination of cytologic and architectural features of these tumors., Methods: Specimens of tumor tissue (5-microm-thick sections) were examined independently by two pathologists, who were unaware of the case or control subject status, for the presence of cell mitosis, lymphocytic infiltration, continuous pushing margins, and solid sheets of cancer cells; cell nuclei, cell nucleoli, cell necrosis, and cell borders were also evaluated. The resulting data were combined with previously available information on tumor type and tumor grade and further evaluated by multifactorial analysis. All statistical tests are two-sided., Results: Cancers associated with BRCA1 mutations exhibited higher mitotic counts (P = .001), a greater proportion of the tumor with a continuous pushing margin (P<.0001), and more lymphocytic infiltration (P = .002) than sporadic (i.e., control) cancers. Cancers associated with BRCA2 mutations exhibited a higher score for tubule formation (fewer tubules) (P = .0002), a higher proportion of the tumor perimeter with a continuous pushing margin (P<.0001), and a lower mitotic count (P = .003) than control cancers., Conclusions: Our study has identified key features of the histologic phenotypes of breast cancers in carriers of mutant BRCA1 and BRCA2 genes. This information may improve the classification of breast cancers in individuals with a family history of the disease and may ultimately aid in the clinical management of patients.

Several BRCA2 mutations are found to occur in geographically diverse breast and ovarian cancer families. To investigate both mutation origin and mutation-specific phenotypes due to BRCA2, we constructed a haplotype of 10 polymorphic short tandem-repeat (STR) markers flanking the BRCA2 locus, in a set of 111 breast or breast/ovarian cancer families selected for having one of nine recurrent BRCA2 mutations. Six of the individual mutations are estimated to have arisen 400-2,000 years ago. In particular, the 6174delT mutation, found in approximately 1% of individuals of Ashkenazi Jewish ancestry, was estimated to have arisen 29 generations ago (1-LOD support interval 22-38). This is substantially more recent than the estimated age of the BRCA1 185delAG mutation (46 generations), derived from our analogous study of BRCA1 mutations. In general, there was no evidence of multiple origins of identical BRCA2 mutations. Our study data were consistent with the previous report of a higher incidence of ovarian cancer in families with mutations in a 3.3-kb region of exon 11 (the ovarian cancer cluster region [OCCR]) (P=.10); but that higher incidence was not statistically significant. There was significant evidence that age at diagnosis of breast cancer varied by mutation (P<.001), although only 8% of the variance in age at diagnosis could be explained by the specific mutation, and there was no evidence of family-specific effects. When the age at diagnosis of the breast cancer cases was examined by OCCR, cases associated with mutations in the OCCR had a significantly older mean age at diagnosis than was seen in those outside this region (48 years vs. 42 years; P=.0005).

Background and Purpose: The purpose of this study is to evaluate overall survival in BRCA1 or BRCA2 breast cancer patients, describe presenting stage, review histologic findings and evaluate response to radiotherapy., Materials and Methods: A retrospective study was performed evaluating breast cancer patients with known mutations of BRCA1 or BRCA2. Patients from 12 different pedigrees were cross-referenced with the Utah Cancer Registry (UCR), histologic findings were verified and radiotherapy records were reviewed for acute response to treatment. Actuarial survival calculations were performed and patients were matched for age, date of diagnosis and tumor size., Results: Thirty breast cancer patients with BRCA1 mutations were found to have 34 breast cancers (four had bilateral metachronous lesions) and 20 breast cancer patients with BRCA2 mutations were found to have 22 breast cancers (two had bilateral metachronous disease). The median age at diagnosis was 49 years (range 21-77 years) and 42 years (range 23-83 years), respectively, for BRCA1 and BRCA2 patients. Unusual histologic types of breast cancers were represented with 7% (4/56) medullary and 5% (3/56) lobular carcinomas. Complete staging was possible for 63% (35/56) of cancers. Stages I, II, III and IV represented 26, 63, 6 and 6% of cancers, respectively. The most severe radiation reaction was moist desquamation which was self-limiting and developed in 29% (6/21) of irradiated patients. The mean follow-up was 9.8 and 7.5 years for BRCA1 and BRCA2 cancers, respectively. Kaplan-Meier survival analysis demonstrated 5-year survival values of 75% for BRCA1 patients, 73% for BRCA2 patients, 70% for matched controls and 69% for UCR controls. No statistically significant differences were evident between the groups at 5 or 10 years., Conclusions: Despite their younger age at presentation, breast cancer patients harboring BRCAI or BRCA2 mutations present at a similar stage, display a normal acute reaction to radiotherapy and have a similar prognosis when compared with sporadic breast cancer patients.

The contribution of BRCA1 and BRCA2 to inherited breast cancer was assessed by linkage and mutation analysis in 237 families, each with at least four cases of breast cancer, collected by the Breast Cancer Linkage Consortium. Families were included without regard to the occurrence of ovarian or other cancers. Overall, disease was linked to BRCA1 in an estimated 52% of families, to BRCA2 in 32% of families, and to neither gene in 16% (95% confidence interval [CI] 6%-28%), suggesting other predisposition genes. The majority (81%) of the breast-ovarian cancer families were due to BRCA1, with most others (14%) due to BRCA2. Conversely, the majority of families with male and female breast cancer were due to BRCA2 (76%). The largest proportion (67%) of families due to other genes was found in families with four or five cases of female breast cancer only. These estimates were not substantially affected either by changing the assumed penetrance model for BRCA1 or by including or excluding BRCA1 mutation data. Among those families with disease due to BRCA1 that were tested by one of the standard screening methods, mutations were detected in the coding sequence or splice sites in an estimated 63% (95% CI 51%-77%). The estimated sensitivity was identical for direct sequencing and other techniques. The penetrance of BRCA2 was estimated by maximizing the LOD score in BRCA2-mutation families, over all possible penetrance functions. The estimated cumulative risk of breast cancer reached 28% (95% CI 9%-44%) by age 50 years and 84% (95% CI 43%-95%) by age 70 years. The corresponding ovarian cancer risks were 0.4% (95% CI 0%-1%) by age 50 years and 27% (95% CI 0%-47%) by age 70 years. The lifetime risk of breast cancer appears similar to the risk in BRCA1 carriers, but there was some suggestion of a lower risk in BRCA2 carriers <50 years of age.

BRCA1 is a breast and ovarian cancer susceptibility gene. An inferred germline regulatory mutation was previously reported in the BRCA1-linked kindred K2035, based on the absence of transcripts from the BRCA1 allele associated with the cancer susceptibility haplotype. In this study, the promoter region of BRCA1 was examined in individuals from K2035 for evidence of a mutation which could halt transcription. Evaluation of a polymorphism located within intron 2 of BRCA1 gave results consistent with the presence of a large deletion in K2035 mutation carriers. Southern blot analysis identified unique restriction fragments which occurred as a result of a 14 kb deletion that removed both of BRCA1's transcription start sites (exons 1a and 1b) as well as exon 2. Sequencing indicated that unequal crossover between Alu repeats was the likely cause of the deletion. Similar deletions may be responsible for other reported inferred regulatory mutations, as well as unidentified mutations in families linked to BRCA1.

The penetrance of the BRCA2 gene on chromosome 13q12-13 has been estimated in two large, systematically ascertained, linked families, by use of a maximum-likelihood method to incorporate both cancer-incidence data and 13q marker typings in the families. The cumulative risk of breast cancer in female gene carriers was estimated to be 59.8% by age 50 years (95% confidence interval [95% CI] 25.9%-78.5%) and 79.5% by age 70 years (95% CI 28.9%-97.5%). The cumulative risk of breast cancer in male carriers was estimated to be 6.3% (95% CI 1.4%-25.6%) by age 70 years. There was no evidence of any risk difference between the two families. These results indicate that the lifetime breast cancer risk in BRCA2 carriers, for at least a subset of mutations, is comparable to that for BRCA1. A significant excess of ovarian cancer in gene carriers was observed (relative risk 17.69, based on three cases), but the absolute risk of ovarian cancer was less than that reported for BRCA1. Significant excesses of laryngeal cancer (relative risk 7.67, based on two possible carriers) and prostate cancer (relative risk 2.89, based on five possible carriers) were also observed. One case of ocular melanoma, as well as a second eye cancer of unspecified histology, occurred in obligate gene carriers.

BRCA1 and BRCA2, genes predisposing to early-onset breast cancer, have been isolated and are characterized for mutation spectrum, risks of cancer, and function. The different methodologies to screen for mutations in BRCA1 and BRCA2 are briefly discussed including DNA-based methodologies and potential new assays. The numbers and types of mutations identified to date are described, including the problems of ascribing risk to missense mutations. Recurring, possibly founding mutations have been identified in several populations including Ashkenazi Jews, Icelanders, Swedes, and African Americans. From population-based studies, estimates are that 6%-10% of breast cancers are due to mutations in BRCA1 and BRCA2. Knowledge of mutation status raises additional questions including the interpretation of negative tests and the risks of breast and other cancers associated with positive test results.

BRCA1 germline mutations confer susceptibility to familial breast and ovarian cancer. Mutational hot spots have never been detected in BRCA1 cDNA. Some mutations have been reported several times whereas some others appear to be population-related. In this study a group of 36 Italian families were analysed for BRCA1 germline mutations. All of them were screened by allele-specific oligonucleotide hybridization (ASO) for three recurrent mutations (185delAG, 5382insC, nt332-T>G). Twenty families, selected because of their high risk of carrying BRCA1 mutations, were subjected to analysis of the entire coding sequence of the gene. A total of eight mutations were found. ASO screening demonstrated only one known mutation in one patient, whereas cycle sequencing revealed five new mutations. Three of these new mutations were frameshifts: one occurred in exon 11 (1499insA), one in exon 16 (4873delCA) and one in the splice site of exon 3 (252delAAgt). Two were missense mutations (Cys64Arg; Asn158Tyr). The same frameshift mutation, 1499insA, was detected in three unrelated families. Haplotype analysis supported the hypothesis that two of these families may have had common ancestors, whereas in the third family the analysis was uninformative. BRCA1 germline mutations were found in one out of two families with ovarian cancer, in five out of eight families with breast-ovarian cancer, and in two out of 11 families with breast cancer. All three families with 1499insA mutations included at least one case of ovarian cancer. The majority of the ovarian cancers (4/5) associated with detectable BRCA1 germline mutations were of serous histotype.

Background: We aimed to find out the proportion of breast cancers in Ashkenazi Jewish women attributable to the frameshift mutation at position 185 involving the deletion of adenine and guanine (185delAG) in the breast cancer gene BRCA1., Methods: We studied 107 Ashkenazi Jewish women with breast cancer seen at medical oncology and genetic counseling clinics in New York over a three and a half year period beginning in 1992. 80 of the women were diagnosed before age 42 years; the other 27 were diagnosed between 42 and 50 years and had a positive family history. Genomic DNA testing by PCR amplification was done to identify any 185delAG mutations of the BRCA1 gene., Findings: Of the 80 women diagnosed before the age of 42 years, 16 (20%, 95% CI 11.2-28.8) were heterozygous for the mutation. All 16 women had at least one first-degree or second-degree relative with breast or ovarian cancer. Of 27 probands diagnosed with breast cancer between the ages of 42 and 50 years who had at least one first-degree relative affected with breast or ovarian cancer, 8 (30%, 95% CI 12-47) had 185delAG mutations., Interpretation: These data suggest that screening for the 185delAG mutation may be useful in genetic counselling of these women where options for detection and prevention of possible cancers can be discussed.

The lifetime risk of breast cancer may approach 80-90% in women who have germline mutations of either of two genes, BRCA1 or BRCA2. A single BRCA1 mutation, 185delAG, has been noted in approximately 20% of Ashkenazi Jewish women with early onset breast cancer and in 0.9% of the Ashkenazi population. We recently detected a 6174delT frameshift mutation in BRCA2 in an hereditary breast cancer kindred of Ashkenazi Jewish ancestry. Here, we investigated the frequency of this mutation in 200 women with early-onset breast cancer. Six of 80 Ashkenazi Jewish women (8%) diagnosed with breast cancer before the age of 42, wer heterozygous for the 6174delT mutation, compared to none of 93 non-Jewish women diagnosed with breast cancer at the same age (P = .005). These cases were ascertained without regard to family history. Two of 27 (7%) additional Jewish families in which the proband was diagnosed with breast cancer at age 42 to 50 and had a family history of breast or ovarian cancer had germline 6174delT mutations. The results of this report suggest that a recurrent mutation of BRCA1 and a recurrent mutation BRCA2 together may account for over a quarter of all early-onset breast cancer in the setting of a personal or family history of ovarian cancer in Ashkenazi Jewish women.