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Pregnancy reduces maternal risk of breast cancer in the long term, but the biological determinants of the protection are unknown. Animal experiments suggest that estrogens and progesterone could be involved, but direct human evidence is scant. A case-control study (536 cases and 1,049 controls) was nested within the Finnish Maternity Cohort. Eligible were primiparous women who delivered at term a singleton offspring before age 40. For each case, two individually matched controls by age (+/- 6 months) and date of sampling (+/- 3 months) were selected. Estradiol, estrone and progesterone in first-trimester serum were measured by high-performance liquid chromatography tandem mass spectrometry and sex-hormone binding globulin (SHBG) by immunoassay. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through conditional logistic regression. In the whole study population there was no association of breast cancer with any of the studied hormones. In analyses stratified by age at diagnosis, however, estradiol concentrations were positively associated with risk of breast cancer before age 40 (upper quartile OR, 1.81; CI, 1.083.06), but inversely associated with risk in women who were diagnosed =age 40 (upper quartile OR, 0.64; CI, 0.401.04), pinteraction 0.004. Risk estimates for estrone mirrored those for estradiol but were less pronounced. Progesterone was not associated with risk of subsequent breast cancer. Our results provide initial evidence that concentrations of estrogens during the early parts of a primiparous pregnancy are associated with maternal risk of breast cancer and suggest that the effect may differ for tumors diagnosed before and after age 40.

Background: Several sexually transmitted infections (STI) have been reported to interact with human papillomavirus (HPV) in the etiology of cervical cancer. A large cohort study is required to obtain a both unbiased and stable estimate of their effects. Methods: Four major biobanks in the Nordic Countries containing samples from about 1,000,000 subjects were linked with nation-wide cancer registries. Serum samples from 604 women with invasive cervical cancer (ICC) diagnosed on average 10 years after sampling and 2,980 matched control women were retrieved and analyzed with serology for key STI. Results: Exposure to HPV16 was the strongest risk factor for cervical cancer [ OR = 2.4; 95% confidence interval (CI), 2.0-3.0], particularly for squamous cell carcinoma (OR = 2.9; 95% CI, 2.2-3.7). HPV18 was strongly associated with increased risk for adenocarcinoma (OR = 2.3; 95% CI, 1.3-4.1). Baseline seropositivity for HPV16 did not confer any increased risk for HPV18 DNA-positive cancer and conversely HPV18 seropositivity had no association with HPV16 DNA-positive cancers. HPV6 had no effect on its own (OR = 1.1; 95% CI, 0.9-1.3), but had an antagonistic effect on the risk conferred by HPV16 (P < 0.01). Herpes simplex virus 2 had little or no association (OR = 1.1; 95% CI, 0.8-1.4). Previous exposure to Chlamydia trachomatis, as indicated by serum antibodies, had a strongly increased risk for cervical cancer (OR = 1.9; 95% CI, 1.5-2.3). Conclusions: A large prospective study has assessed the role of different STIs in cervical cancer. Impact: Prospective evidence supports cofactor role of some STI in cervical cancer. Cancer Epidemiol Biomarkers Prev; 20(12); 2541-50. (C) 2011 AACR.

This is the first prospective study providing initial evidence that elevated androgens play a role in the pathogenesis of SCST. Impact: Our study may note a particular need for larger confirmatory investigations on sex steroids and NEOC. Cancer Epidemiol Biomarkers Prev; 20(2); 324-36. ©2010 AACR.

According to the leading hypothesis on testicular cancer (TC) etiology exposure to a specific pattern of steroid hormones in utero, in particular, to high levels of estrogens and low levels of androgens is the major determinant of TC risk in the offspring. We performed a case-referent study nested within Finnish, Swedish and Icelandic maternity cohorts exploiting early pregnancy serum samples to evaluate the role of maternal endogenous steroid hormones with regard to the risk of TC. TC cases and referents were aged between 0 and 25 years. For each case-index mother pair, three or four matched referent-referent mother pairs were identified using national population registries. First trimester or early second trimester sera were retrieved from the index mothers of 73 TC cases and 286 matched referent mothers, and were tested for dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, estradiol, estrone, and sex hormone binding globulin (SHBG). Offspring of mothers with high DHEAS levels had a significantly decreased risk of TC (OR for highest vs. lowest DHEAS quartile, 0.18 (95% CI 0.06-0.58). In contrast, offspring of mothers with high androstenedione levels had an increased risk of TC (OR 4.1; 95% CI 1.2-12.0). High maternal total estradiol level also tended to be associated with an increased risk of TC in the offspring (OR 32; 95% CI 0.98-1,090). We report the first direct evidence that interplay of maternal steroid hormones in the early pregnancy is important in the etiology of TC in the offspring. (c) 2009 UICC.

Some large ecological studies have noted a significant association of testicular cancer (TC) with maternal smoking during pregnancy, while several more controlled studies have been negative. It has been difficult to obtain reliable data on exposure because of the long lag time to cancer diagnosis. We performed a case-control study nested within Finnish, Swedish and Icelandic maternity cohorts exploiting early pregnancy serum samples to evaluate the role of maternal smoking in the risk of TC in the offspring. After reviewing the literature, we also performed a meta-analysis of published studies. For each index mother of the TC patient, three to nine matched control mothers with a cancer-free son born at the same time as the TC case were identified within each cohort. First trimester sera were retrieved from the 70 index mothers and 519 control mothers and were tested for cotinine level by a novel HPLC-MS-MS method developed. No statistically significant association between maternal cotinine level and risk of TC in the offspring was found (OR 0.68; 95% CI 0.35, 1.34). This is the first study based on individual exposure measurements. Its results agree with our meta-analysis of seven previous epidemiological studies (total number of 2149 cases, 2762 controls) using indirect exposure assessment (OR 1.0; 95% CI 0.88, 1.12).

During recent decades the incidence of testicular cancer (TC) has increased rapidly around the world. Associated exogenous etiological factors might therefore be identifiable. We performed a case-control study nested within Finnish, Swedish and Icelandic maternity cohorts exploiting early pregnancy serum samples to evaluate the role of congenital or neonatal infections with Epstein-Barr virus (EBV) and cytomegalovirus (CMV) as risk factors of TC in the offspring. For each case-index mother pair, three or four matched control-control mother pairs were identified using national population registries. First trimester sera were retrieved from the index mothers of 66 TC cases and 258 matched control mothers, and were tested for antibodies to EBV and CMV. High level of maternal EBV IgG antibodies was associated with significantly increased risk of TC in the offspring (odds ratio (OR), 2.50; 95% confidence interval (CI), 1.15, 5.40), especially with risk of non-seminoma TC (OR, 2.73; 950% CI, 1.25, 5.99) and non-seminoma TC diagnosed under 8 years of age (OR, 2.72; 95% CI, 1.05, 7.04). In contrast, offspring of CMV IgG-seropositive mothers had a decreased risk of TC diagnosed under 8 years of age (OR, 0.35; 95% CI, 0.14, 0.89). Our results suggest that EBV and CMV infections may be associated with TC.

Validity of biobank studies on hormone associated cancers depend on the extent the sample preservation is affecting the hormone measurements. We investigated the effect of long-term storage (up to 22 years) on immunoassay measurements of three groups of hormones and associated proteins: sex-steroids [estradiol, progesterone, testosterone, dihydroepiandrosterone sulphate (DHEAS), sex hormone-binding globulin (SHBG)], pregnancy-specific hormones [human chorionic gonadotropin (hCG), placental growth hormone (pGH), alpha-fetoprotein (AFP)], and insulin-like growth factor (IGF) family hormones exploiting the world largest serum bank, the Finnish Maternity Cohort (FMC). Hormones of interest were analyzed in a random sample of 154 Finnish women in the median age (29.5 years, range 25 to 34 years) of their first pregnancy with serum samples drawn during the first trimester. All hormone measurements were performed using commercial enzyme-linked- or radio-immunoassays. Storage time did not correlate with serum levels of testosterone, DHEAS, hCG, pGH and total IGFBP-1. It had a weak or moderate negative correlation with serum levels of progesterone (Spearman's ranked correlation coefficient (rs)=− 0.36), IGF-I (rs=−0.23) and IGF binding protein (BP)-3 (rs=−0.38), and weak positive correlation with estradiol (rs=0.23), SHBG (rs=0.16), AFP (rs=0.20) and non-phosphorylated IGF binding protein (BP)-1 (rs=0.27). The variation of all hormone levels studied followed the kinetics reported for early pregnancy. Bench-lag time (the time between sample collection and freezing for storage) did not materially affect the serum hormone levels. In conclusion, the stored FMC serum samples can be used to study hormone-disease associations, but close matching for storage time and gestational day are necessary design components of all related biobank studies.

Human papillomavirus (HPV) type 16 is the major cause of cervical carcinoma, the incidence of which is decreasing in western countries. In Finland the incidence is, however, increasing in women aged <40 years, but possible underlying changes in HPV-16 epidemiology are unknown. To assess incidence trends of HPV infections, paired sera from a random sample of 8000 women with two pregnancies/sera within 5 years, taken from the serum bank of the Finnish Maternity Cohort (1983–98), were analysed for HPV-6, -11 and -16 antibodies. For 23–31-year-old women, HPV-16 incidence increased over the period 1983–97. HPV-16 seroprevalence increased from 17 % in 1983–85 to 24 % in 1995–97, but HPV-6 and HPV-11 prevalence was stable at 9–12 % throughout the study period. Epidemic spread of the oncogenic HPV-16, but not the non-oncogenic HPV-types, throughout the 1980s and 1990s preceded an increase in the incidence of cervical carcinoma in fertile-aged Finnish women.

To assess the stability of polyomavirus antibodies in serial samples over time and the incidence and age-specific prevalence of polyomavirus infections, we established enzyme immunoassays (EIAs) using purified yeast-expressed virus-like particles (VLPs) containing the VP1 major capsid proteins of JC virus (JCV) and the AS and SB strains of BK virus (BKV). A random subsample of 150 Finnish women who had serum samples taken during the first trimester of pregnancy and had a second pregnancy during a 5 year follow-up period was selected, grouped by age of first pregnancy. The polyomavirus antibody levels were similar in samples taken during the first and second pregnancies (correlation coefficient 0·93 for BKV SB and 0·94 for JCV). Analysis of serum samples from 290 Swedish children aged 1–13 years, grouped by age in 2 year intervals, demonstrated that BKV seropositivity increased rapidly with increasing age of the children, reaching 98 % seroprevalence at 7–9 years of age, followed by a minor decrease. JCV seroprevalence increased only slowly with increasing age and reaching 72 % positivity among mothers >25 years of age. The age-specific seroprevalence of the human polyomaviruses measured using this VLP-based EIA was similar to previous serosurveys by other methods. The stability of the antibodies over time indicates that polyomavirus seropositivity is a valid marker of cumulative virus exposure, and polyoma VLP-based EIAs may therefore be useful for epidemiological studies of these viruses.