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Background: Postmenopausal pregnenolone and/or progesterone levels in relation to endometrial and ovarian cancer risks have been infrequently evaluated. To address this, we utilized a sensitive and reliable assay to quantify prediagnostic levels of seven markers related to endogenous hormone metabolism. Methods: Hormones were quantified in baseline serum collected from postmenopausal women in a cohort study nested within the Breast and Bone Follow-up to the Fracture Intervention Trial (B~FIT). Women using exogenous hormones at baseline (1992-1993) were excluded. Incident endometrial (n = 65) and ovarian (n = 67) cancers were diagnosed during 12 follow-up years and compared with a subcohort of 345 women (no hysterectomy) and 413 women (no oophorectomy), respectively. Cox models with robust variance were used to estimate cancer risk. Results: Circulating progesterone levels were not associated with endometrial [tertile (T)3 vs. T1 HR (95% confidence interval): 1.87 (0.85-4.11); Ptrend = 0.17] or ovarian cancer risk [1.16 (0.58-2.33); 0.73]. Increasing levels of the progesterone-to-estradiol ratio were inversely associated with endometrial cancer risk [T3 vs. T1: 0.29 (0.09-0.95); 0.03]. Increasing levels of 17-hydroxypregnenolone were inversely associated with endometrial cancer risk [0.40 (0.18-0.91); 0.03] and positively associated with ovarian cancer risk [3.11 (1.39-6.93); 0.01]. Conclusions: Using sensitive and reliable assays, this study provides novel data that endogenous progesterone levels are not strongly associated with incident endometrial or ovarian cancer risks. 17-hydroxypregnenolone was positively associated with ovarian cancer and inversely associated with endometrial cancer. Impact: While our results require replication in large studies, they provide further support of the hormonal etiology of endometrial and ovarian cancers. [ABSTRACT FROM AUTHOR]

Background: The role of progestogens in colorectal cancer development is poorly characterized. To address this, our group developed a highly sensitive assay to measure concentrations of seven markers of endogenous progestogen metabolism among postmenopausal women. Methods: The markers were measured in baseline serum collected from postmenopausal women in a case-cohort study within the breast and bone follow-up to the fracture intervention trial (B~FIT). We followed women not using exogenous hormones at baseline (1992-1993) for up to 12 years: 187 women with incident colorectal cancer diagnosed during follow-up and a subcohort of 495 women selected on strata of age and clinical center. We used adjusted Cox regression models with robust variance to estimate risk for colorectal cancer [hazard ratios (HR), 95% confidence intervals (CI)]. Results: High concentrations of pregnenolone and progesterone were not associated with colorectal cancer [quintile(Q)5 versus Q1: pregnenolone HR, 0.71, 95% CI, 0.40-1.25; progesterone HR, 1.25; 95% CI, 0.71-2.22]. A trend of increasing risk was suggested, but statistically imprecise across quintiles of 17-hydroxypregnenolone (Q2 to Q5 HRs, 0.75-1.44; Ptrend, 0.06). Conclusions: We used sensitive and reliable assays to measure multiple circulating markers of progestogen metabolism. Progestogens were generally unassociated with colorectal cancer risk in postmenopausal women. [ABSTRACT FROM AUTHOR]

Background: Large-scale cancer epidemiology cohorts (CEC) have successfully collected, analyzed, and shared patient-reported data for years. CECs increasingly need to make their data more findable, accessible, interoperable, and reusable, or FAIR. How CECs should approach this transformation is unclear. Methods: The California Teachers Study (CTS) is an observational CEC of 133,477 participants followed since 1995-1996. In 2014, we began updating our data storage, management, analysis, and sharing strategy. With the San Diego Supercomputer Center, we deployed a new infrastructure based on a data warehouse to integrate and manage data and a secure and shared workspace with documentation, software, and analytic tools that facilitate collaboration and accelerate analyses. Results: Our new CTS infrastructure includes a data warehouse and data marts, which are focused subsets from the data warehouse designed for efficiency. The secure CTS workspace utilizes a remote desktop service that operates within a Health Insurance Portability and Accountability Act (HIPAA)- and Federal Information Security Management Act (FISMA)-compliant platform. Our infrastructure offers broad access to CTS data, includes statistical analysis and data visualization software and tools, flexibly manages other key data activities (e.g., cleaning, updates, and data sharing), and will continue to evolve to advance FAIR principles. Conclusions: Our scalable infrastructure provides the security, authorization, data model, metadata, and analytic tools needed to manage, share, and analyze CTS data in ways that are consistent with the NCI's Cancer Research Data Commons Framework. Impact: The CTS's implementation of new infrastructure in an ongoing CEC demonstrates how population sciences can explore and embrace new cloud-based and analytics infrastructure to accelerate cancer research and translation. [ABSTRACT FROM AUTHOR]

Background: Like other cancer epidemiologic cohorts, the California Teachers Study (CTS) has experienced declining participation to follow-up questionnaires; neither the reasons for these declines nor the steps that could be taken to mitigate these trends are fully understood. Methods: The CTS offered their 6th study questionnaire (Q6) in the fall of 2017 using an integrated, online system. The team delivered a Web and mobile-adaptive questionnaire to 45,239 participants via e-mail using marketing automation technology. The study's integrated platform captured data on recruitment activities that may influence overall response, including the date and time invitations and reminders were e-mailed and the date and time questionnaires were started and submitted. Results: The overall response rate was 43%. Participants ages 65 to 69 were 25% more likely to participate than their younger counterparts (OR = 1.25; 95% CI, 1.18-1.32) and nonwhite participants were 28% less likely to participate than non-Hispanic white cohort members (OR = 0.72; 95% CI, 0.68-0.76). Previous questionnaire participation was strongly associated with response (OR = 6.07; 95% CI, 5.50-6.70). Invitations sent after 2 pm had the highest response (OR = 1.75; 95% CI, 1.65-1.84), as did invitations sent on Saturdays (OR = 1.48; 95% CI, 1.36-1.60). Conclusions: An integrated system that captures paradata about questionnaire recruitment and response can enable studies to quantify the engagement patterns and communication desires of cohort members. Impact: As cohorts continue to collect scientific data, it is imperative to collect and analyze information on how participants engage with the study. [ABSTRACT FROM AUTHOR]

Background: Regular users of aspirin may have reduced risk of breast cancer. Few studies have addressed whether risk reduction pertains to specific breast cancer subtypes defined jointly by hormone receptor (estrogen and progesterone receptor) and human epidermal growth factor receptor 2 (HER2) expression. This study assessed the prospective risk of breast cancer (overall and by subtype) according to use of aspirin and other non-steroidal anti-inflammatory medications (NSAIDs) in a cohort of female public school professionals in California.Methods: In 1995 - 1996, participants in the California Teachers Study completed a baseline questionnaire on family history of cancer and other conditions, use of NSAIDs, menstrual and reproductive history, self-reported weight and height, living environment, diet, alcohol use, and physical activity. In 2005-2006, 57,164 participants provided some updated information, including use of NSAIDs and 1457 of these participants developed invasive breast cancer before January 2013. Multivariable Cox proportional hazards regression models provided hazard rate ratios (HRR) for the association between NSAID use and risk of invasive breast cancer as well as hormone receptor- and HER2-defined subtypes.Results: Developing breast cancer was associated inversely with taking three or more tablets of low-dose aspirin per week (23% of participants). Among women reporting this exposure, the HRR was 0.84 (95% confidence interval (CI) 0.72-0.98) compared to those not taking NSAIDs and this was particularly evident in women with the hormone receptor-positive/HER2-negative subtype (HRR = 0.80, 95% CI 0.66-0.96). Use of three or more tablets of "other" NSAIDs was marginally associated with lower risk of breast cancer (HRR = 0.79, 95% CI 0.62-1.00). Other associations with NSAIDs were generally null.Conclusion: Our observation of reduced risk of breast cancer, among participants who took three or more tablets of low-dose aspirin weekly, is consistent with other reports looking at aspirin without differentiation by dose. This is the first report to suggest that the reduction in risk occurs for low-dose aspirin and not for regular-dose aspirin and only among women with the hormone receptor-positive/HER2-negative subtype. This preliminary study builds on previous knowledge and further supports the need for formal cancer chemoprevention studies of low-dose aspirin. [ABSTRACT FROM AUTHOR]

This report is noteworthy, because the GLIOGENE Consortium represents a new generation of epidemiologic consortia. GLIOGENE investigators have created an infrastructure that addresses important limitations of first-generation consortia efforts, which comprised a posteriori harmonization of exposure data and the inclusion of studies that did not include the same--or any--exposure data. As with these first-generation consortia efforts, the GLIOGENE Consortium embraces the primary importance of sample size, and to achieve that, the consortium tolerates different study designs that permit heterogeneity in case and control ascertainment. In contrast, however, the consortium's Glioma International Case-Control (GICC) Study incorporates systematic collection of exposure data from both cases and controls to facilitate downstream evaluation of exposure associations and gene-environment interactions. The described GICC Study thus serves as a model for future epidemiologic efforts that reflects a paradigm shift whereby studies are now being conducted with the expectation of downstream collaboration, thus demanding coordination and harmonization of apparently independent efforts at the time of study initiation rather than at study completion. [ABSTRACT FROM AUTHOR]

Background: The ability of tamoxifen and raloxifene to decrease breast cancer risk varies among different breast cancer subtypes. It is important to determine one's subtype-specific breast cancer risk when considering chemoprevention. A number of single nucleotide polymorphisms (SNPs), including one in caspase-8 (CASP8), have been previously associated with risk of developing breast cancer. Because caspase-8 is an important protein involved in receptor-mediated apoptosis whose activity is affected by estrogen, we hypothesized that additional SNPs in CASP8 could be associated with breast cancer risk, perhaps in a subtype-specific manner.Methods: Twelve tagging SNPs of CASP8 were analyzed in a nested case control study (1,353 cases and 1,384 controls) of non-Hispanic white women participating in the California Teachers Study. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each SNP using all, estrogen receptor (ER)-positive, ER-negative, human epidermal growth factor receptor 2 (HER2)-positive, and HER2-negative breast cancers as separate outcomes.Results: Several SNPs were associated with all, ER-positive, and HER2-positive breast cancers; however, after correcting for multiple comparisons (i.e., p < 0.0008), only rs2293554 was statistically significantly associated with HER2-positive breast cancer (OR = 1.98, 95% CI 1.34-2.92, uncorrected p = 0.0005).Conclusions: While our results for CASP8 SNPs should be validated in other cohorts with subtype-specific information, we conclude that some SNPs in CASP8 are associated with subtype-specific breast cancer risk. This study contributes to our understanding of CASP8 SNPs and breast cancer risk by subtype. [ABSTRACT FROM AUTHOR]

In this issue of Cancer Epidemiology, Biomarkers & Prevention, Gallicchio and colleagues analyze recent rare-cancers research and suggest broad themes for accelerating progress in this important area. Whether the type of portfolio creation and portfolio management strategies that have worked for common cancers also work best for rare cancers warrants asking. This commentary argues for consideration of additional approaches. Incorporating principles and successes from large-scale network-based clinical trials and from advocacy-based research, and new ways to approach consortia, might accelerate the quantity and improve the quality of future rare-cancer research. Rare cancers significantly influence the overall cancer burden and cancer disparities. Creative community-based approaches to improve rare-cancers research should be considered. [ABSTRACT FROM AUTHOR]

Background: A potential protective role for estrogen in colon carcinogenesis has been suggested based on exogenous hormone use, but it is unclear from previous studies whether endogenous estrogens are related to colorectal cancer risk. These few prior studies focused on parent estrogens; none evaluated effects of estrogen metabolism in postmenopausal women. Methods: We followed 15,595 women (ages 55-80 years) enrolled in the Breast and Bone Follow-up to the Fracture Intervention Trial (BFIT) who donated blood between 1992 and 1993 for cancer through December 2004. A panel of 15 estrogen metabolites (EM), including estradiol and estrone, were measured in serum from 187 colorectal cancer cases and a subcohort of 501 women not using exogenous hormones at blood draw. We examined EM individually, grouped by pathway (hydroxylation at the C-2, C-4, or C-16 position) and by ratios of the groupings using Cox proportional hazards regression models. Results: No significant associations were seen for estrone (HRQ4 vs. Q1 = 1.15; 95% CI, 0.69-1.93; Ptrend = 0.54), estradiol (HRQ4 vs. Q1 = 0.98; 95% CI, 0.58-1.64; Ptrend > 0.99), or total EM (the sum of all EM; HRQ4 vs. Q1 = 1.35; 95% CI, 0.81-2.24; Ptrend = 0.33). Most metabolites in the 2-, 4-, or 16-pathway were unrelated to risk, although a borderline trend in risk was associated with high levels of 17-epiestriol. Conclusion: Circulating estrogens and their metabolites were generally unrelated to colorectal cancer risk in postmenopausal women. Impact: Additional studies are needed to understand how exogenous estrogen may prevent colorectal cancer. [ABSTRACT FROM AUTHOR]

Previous results from research on menopausal hormone therapy (MHT) and lung cancer survival have been mixed and most have not studied women who used estrogen therapy (ET) exclusively. We examined the associations between MHT use reported at baseline and lung cancer-specific mortality in the prospective California Teachers Study cohort. Among 727 postmenopausal women diagnosed with lung cancer from 1995 through 2007, 441 women died before January 1, 2008. Hazard Ratios (HR) and 95% Confidence Intervals (CI) for lung-cancer-specific mortality were obtained by fitting multivariable Cox proportional hazards regression models using age in days as the timescale. Among women who used ET exclusively, decreases in lung cancer mortality were observed (HR, 0.69; 95% CI, 0.52–0.93). No association was observed for estrogen plus progestin therapy use. Among former users, shorter duration (<5 years) of exclusive ET use was associated with a decreased risk of lung cancer mortality (HR, 0.56; 95% CI, 0.35–0.89), whereas among recent users, longer duration (>15 years) was associated with a decreased risk (HR, 0.60; 95% CI, 0.38–0.95). Smoking status modified the associations with deceases in lung cancer mortality observed only among current smokers. Exclusive ET use was associated with decreased lung cancer mortality. [ABSTRACT FROM AUTHOR]

The article discusses a case-control study which examined the association of circulating adipokine levels with the risk of endometrial cancer among postmenopausal women. Topics discussed include the inverse association of adiponectin levels with endometrial cancer risk, positive association for elevated leptin levels and nonsignificant positive associations for visfatin.

Ruth Pfeiffer and colleagues describe models to calculate absolute risks for breast, endometrial, and ovarian cancers for white, non-Hispanic women over 50 years old using easily obtainable risk factors. Please see later in the article for the Editors' Summary [ABSTRACT FROM AUTHOR]

Endometrial cancer risk is strongly influenced by obesity, but the mechanisms of action remain unclear. Leptin and adiponectin, secreted from adipose tissue, reportedly play a role in such carcinogenic processes as cell proliferation, angiogenesis, and insulin regulation. In this case-control study, nested within the Breast and Bone Follow-up of the Fracture Intervention Trial (n=15 595), we assessed pre-diagnostic serum leptin, total adiponectin, and high-molecular-weight (HMW) adiponectin in relation to endometrial cancer among postmenopausal women. During the 10-year follow-up, 62 incident endometrial cases were identified and matched to 124 controls on age, geographical site, time of fasting blood draw at baseline (1992-1993), and trial participation status. Adipokines and C-peptide were measured by ELISA. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated via conditional logistic regression, with exposures categorized in tertiles (T). Multivariable models considered C-peptide, BMI (kg/m2), and estradiol (E2) as potential confounders. Endometrial cancer risk was significantly associated with higher leptin levels, adjusted for E2 and C-peptide (ORT3 vs T1=2.96; 95% CI, 1.21-7.25; P trend !0.01). After further adjustment for BMI, the estimates were attenuated and the positive trend was no longer statistically significant (ORT3 vs T1=2.11; 95% CI, 0.69-6.44; P trend=0.18). No significant associations were observed with adiponectin or HMW adiponectin and endometrial cancer. Our findings with leptin suggest that the leptin-BMI axis might increase endometrial cancer risk through mechanisms other than estrogen-driven proliferation. Continued exploration of these pathways in larger prospective studies may help elucidate mechanisms underlying observed obesity-endometrial cancer associations. [ABSTRACT FROM AUTHOR]

The article discusses research on the link between alcohol consumption and breast cancer risk among postmenopausal women who stopped taking hormone therapy (HT). Background of California Teachers Study participants such as details of their daily alcohol intake and previous HT use is given. The administration of follow-up questionnaires regarding invasive breast cancer diagnosis is reported. The substantial adverse effects of HT and alcohol on breast cancer risk are also explored.

The article reports on the California Teacher Study (CTS) which examined hormone therapy (HT) use in relation to lung cancer risk among postmenopausal women between 1995 and 2007. The Multivariable Cox proportional hazards regression models are described as the methods used, with age as the time metric. Results show that recent or past HT use, whether estrogen alone or with progestin, and taking into consideration the women's menopausal status and smoking history, is not associated with lung cancer risk.

The article discusses a study which evaluated the hypothesis that the genetic risk factors of obesity and diabetes and the risk of endometrial cancer. The authors genotyped tag-single nucleotide polymorphisms (SNP) and candidate SNPs in fat mass and obesity-associated gene (FTO) and hematopoietically-expressed homeobox protein (HHEX) in a primary set of 417 endometrial cancer cases. It was found that there was no association between endometrial cancer and the phenotypes.

Background. Estrogen plays a major role in endometrial carcinogenesis, suggesting that common variants of genes in the sex hormone metabolic pathway may be related to endometrial cancer risk. In support of this view, variants in CYP19A1 [cytochrome P450 (CYP), family 19, subfamily A, polypeptide 1] have been associated with both circulating estrogen levels and endometrial cancer risk. Associations with variants in other genes have been suggested, but findings have been inconsistent. Methods. We examined 36 sex hormone-related genes using a tagging approach in a population-based case–control study of 417 endometrial cancer cases and 407 controls conducted in Poland. We evaluated common variation in these genes in relation to endometrial cancer risk using sequential haplotype scan, variable-sized sliding window and adaptive rank-truncated product (ARTP) methods. Results. In our case–control study, the strongest association with endometrial cancer risk was for AR (androgen receptor; ARTP P = 0.006). Multilocus analyses also identified boundaries for a region of interest in AR and in CYP19A1 around a previously identified susceptibility loci. We did not find evidence for consistent associations between previously reported candidate single-nucleotide polymorphisms in this pathway and endometrial cancer risk. Discussion. In summary, we identified regions in AR and CYP19A1 that are of interest for further evaluation in relation to endometrial cancer risk in future haplotype and subsequent fine mapping studies in larger study populations. [ABSTRACT FROM PUBLISHER]

The article reports on the study which establishes the association of menstrual and reproductive factors with the cancers in the upper gastrointestinal tract (UGI). It notes that the UGI tract cancers risks which involve the head and neck, esophagus, and stomach are higher in men to develop adenicarcinomas and squamous cell carcinomas. It implies that the higher levels of progesterone and estrogen levels in women could explain the lower incidence rates of UGI cancers in women than in men.

The article discusses the relation between body mass index (BMI) and ovarian cancer risk with the use of menopausal hormone therapy (MHT). The study involved 94,525 women in the U.S. wherein 303 of the respondents have epithelial ovarian cancer. Researchers expect that obesity is associated with enhanced ovarian cancer risk through a hormonal mechanism.

The article presents a study which aims to look on the correlation of androgen receptor (AR) genetic variation and the risk of acquiring endometrial cancer. Researchers have conducted an assessment by measuring the haplotype-tagging single nucleotide polymorphisms (htSNP) found in AR and found insignificant correlation. Moreover, the said study has provided meager proof on the link between AR genetic variation and the risk of the mentioned cancer.

Background: Multidisciplinary attempts to understand the etiology of breast cancer are expanding to increasingly include new potential markers of disease risk. Those efforts may have maximal scientific and practical influence if new findings are placed in context of the well-understood lifestyle and reproductive risk factors or existing risk prediction models for breast cancer. We therefore evaluated known risk factors for breast cancer in a cancer screening trial that does not have breast cancer as a study endpoint but is large enough to provide numerous analytic opportunities for breast cancer. Methods: We evaluated risk factors for breast cancer (N = 2085) among 70,575 women who were randomized in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Using Poisson regression, we calculated adjusted relative risks [RRs, with 95% confidence intervals (CIs)] for lifestyle and reproductive factors during an average of 5 years of follow-up from date of randomization. Results: As expected, increasing age, nulliparity, positive family history of breast cancer, and use of menopausal hormone therapy were positively associated with breast cancer. Later age at menarche (16 years or older vs. < 12: RR = 0.81, 95% CI, 0.65-1.02) or menopause (55 years or older vs. < 45: RR = 1.29, 95% CI, 1.03-1.62) were less strongly associated with breast cancer than was expected. There were weak positive associations between taller height and heavier weight, and only severe obesity [body mass index (BMI; kg/m²) 35 or more vs. 18.5-24.9: RR = 1.21, 95% CI, 1.02-1.43] was statistically significantly associated with breast cancer. Conclusion: The ongoing PLCO trial offers continued opportunities for new breast cancer investigations, but these analyses suggest that the associations between breast cancer and age at menarche, age at menopause, and obesity might be changing as the underlying demographics of these factors change. Clinical Trials Registration: http://www.clinicaltrials.gov, NCT00002540. [ABSTRACT FROM AUTHOR]

The article focuses on the study which investigates the association between physical activity and postmenopausal breast cancer risk in women in the U.S. It states that the study used Cox regression to estimate the relative risk (RR) and 95 percent confidence interval of postmenopausal breast cancer overall and by tumor characteristics. The study concluded that physical activity was associated with reduced postmenopausal breast cancer risk, particularly to estrogen receptor (ER)-negative tumors.

The article presents a pooled analysis which tests the hypothesis whether the presence of one or both A alleles in the single nucleotide polymorphisms (SNP) results in an increased endometrial cancer risk. It notes that common CYP19A1 variants are linked with the 10% to 20% increase in the levels of circulating estrogen in postmenopausal women. It analyzes 4,998 endometrial cancer cases and 8,285 controls for ten studies in the Epidemiology of Endometrial Cancer Consortium.

The article focuses on the study regarding the link between menopausal hormone therapy and colorectal cancer risk. It evaluates the relation of colorectal cancer risk with the duration and recency of specific menopausal hormone therapy formulations and regimens among postmenopausal women. The study reveals a decreased risk of colorectal cancer among users of unposed estrogen therapy. It concludes that estrogen plus progestin use is directly associated with colorectal cancer risk reduction.

The article examines the effects of estrogen therapy (ET) and estrogen plus progestin therapy (EPT) on breast cancer risk. It shows that both ET and EPT are associated with breast cancer risks with the magnitude of increase varying according to body mass and clinical characteristics of the tumors. The article analyzes data from 126,638 females ages 50 to 71 years at baseline.

Background: Histopathologic diagnosis of endometrial biopsies is used to estimate the risk of progression to carcinoma and guide clinical management. Problems with the widely used World Health Organization (WHO) system for classifying endometrial hyperplasia (EH) have prompted the development of an alternative system based on endometrial intraepithelial neoplasia (EIN). The authors estimated progression risk associated with EIN among endometrial biopsies in a nested case-control study of EH progression.Methods: Index biopsies with original community pathology diagnoses of disordered proliferative endometrium (DPEM) or EH that were independently confirmed by a panel of pathologists were independently reviewed and assigned EIN classifications (inadequate, benign, EIN, or cancer) by a second panel of pathologists. Cases (N = 138) progressed to carcinoma at least 1 year (median, 6 years) after their index biopsy. Controls (N = 241) also had EH, did not progress to carcinoma, and were individually matched to cases based on age at EH, date of EH, and length of follow-up. By using conditional logistic regression, the authors estimated relative risks (RRs) with 95% confidence intervals (95% CIs) for progression to carcinoma for EIN versus benign.Results: In the EIN system, 71 (52.6%) cases and 159 (66.8%) controls were classified as benign and 42 (31.1%) cases and 65 (27.3%) controls were classified as EIN. The RR for EIN versus benign was 7.76 (95% CI, 3.36-17.91). In the WHO system, the RR for atypical hyperplasia (AH) versus DPEM, simple hyperplasia, or complex hyperplasia was 9.19 (95% CI, 3.87-21.83).Conclusions: Among women observed for at least 1 year after receiving a biopsy-based EH diagnosis, EIN and AH were both found to have similarly increased risks of progression to carcinoma. [ABSTRACT FROM AUTHOR]

Most risk factors for male breast cancer have been derived from retrospective studies that may reflect selective recall. In the prospective National Institutes of Health-AARP Diet and Health Study, we studied 324920 men, among whom 121 developed breast cancer. Men who reported a first-degree relative with breast cancer had an increased risk of breast cancer (relative risk [RR] = 1.92, 95% confidence interval [Cl] = 1.19 to 3.09). Among the medical conditions examined, a new finding emerged regarding increased male breast cancer risk associated with a history of a bone fracture (RR = 2.20, 95% Cl = 1.24 to 3.91). Obesity was positively related to risk (RR = 1.79, 95% Cl = 1.10 to 2.91, for body mass indices of ⩾30 vs <25 kg/m2) and physical activity inversely related, even after adjustment for body mass index. Smokers were at somewhat elevated risk, although trends with smoking characteristics were inconsistent. Alcohol consumption was not related to risk. The identified risk factors show some commonalities with female breast cancer and indicate the importance of hormonal mechanisms. Differences in risk factors may reflect unique mechanisms associated with androgens and their ratio to bioavailable estrogens. [ABSTRACT FROM AUTHOR]

Background: Some, but not all, published results have shown an association between circulating blood levels of some insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) and the subsequent risk for prostate cancer. Purpose: To assess the association between levels of IGFs and IGFBPs and the subsequent risk for prostate cancer. Data Sources: Studies identified in PubMed, Web of Science, and CancerLit. Study Selection: The principal investigators of all studies that published data on circulating concentrations of sex steroids, IGFs, or IGFBPs and prostate cancer risk using prospectively collected blood samples were invited to collaborate. Data Extraction: Investigators provided individual participant data on circulating concentrations of IGF-I, IGF-II, IGFBP-II, and IGFBPIII and participant characteristics to a central data set in Oxford, United Kingdom. Data Synthesis: The study included data on 3700 men with prostate cancer and 5200 control participants. On average, case patients were 61.5 years of age at blood collection and received a diagnosis of prostate cancer 5 years after blood collection. The greater the serum IGF-I concentration, the greater the subsequent risk for prostate cancer (odds ratio [OR] in the highest vs. lowest quintile, 1.38 [95% CI, 1.19 to 1.60]; P < 0.001 for trend). Neither IGF-II nor IGFBP-II concentrations were associated with prostate cancer risk, but statistical power was limited. Insulin-like growth factor I and IGFBP-III were correlated (r = 0.58), and although IGFBP-III concentration seemed to be associated with prostate cancer risk, this was secondary to its association with IGF-I levels. Insulin-like growth factor I concentrations seemed to be more positively associated with low-grade than high-grade disease; otherwise, the association between IGFs and IGFBPs and prostate cancer risk had no statistically significant heterogeneity related to stage or grade of disease, time between blood collection and diagnosis, age and year of diagnosis, prostate-specific antigen level at recruitment, body mass index, smoking, or alcohol intake. Limitations: Insulin-like growth factor concentrations were measured in only 1 sample for each participant, and the laboratory methods to measure IGFs differed in each study. Not all patients had disease stage or grade information, and the diagnosis of prostate cancer may differ among the studies. Conclusion: High circulating IGF-I concentrations are associated with a moderately increased risk for prostate cancer. [ABSTRACT FROM AUTHOR]