Prediagnostic serum concentrations of per- and polyfluoroalkyl substances and risk of papillary thyroid cancer in the Finnish Maternity Cohort.

Human exposure to per- and polyfluoroalkyl substances (PFAS) occurs globally through contaminated food, dust, and drinking water. Studies of PFAS and thyroid cancer have been limited. We conducted a nested case-control study of prediagnostic serum levels of 19 PFAS and papillary thyroid cancer (400 cases, 400 controls) in the Finnish Maternity Cohort (pregnancies 1986-2010; follow-up through 2016), individually matched on sample year and age. We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for log2 transformed and categorical exposures, overall and stratified by calendar period, birth cohort, and median age at diagnosis. We adjusted for other PFAS with Spearman correlation rho = 0.3-0.6. Seven PFAS, including perfluoroctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), N-ethyl-perfluorooctane sulfonamidoacetic acid (EtFOSAA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorohexane sulfonic acid (PFHxS) were detected in >50% of women. These PFAS were not associated with risk of thyroid cancer, except for PFHxS, which was inversely associated (OR log2 = 0.82, 95% CI: 0.70-0.97). We observed suggestive but imprecise increased risks associated with PFOA, PFOS, and EtFOSAA for those diagnosed at ages <40 years, whereas associations were null or inverse among those diagnosed at 40+ years (P-interaction: .02, .08, .13, respectively). There was little evidence of other interactions. These results show no clear association between PFAS and papillary thyroid cancer risk. Future work would benefit from evaluation of these relationships among those with higher exposure levels and during periods of early development when the thyroid gland may be more susceptible to environmental harms.

Associations between pregnancy-related factors and birth characteristics with risk of rare uterine cancer subtypes: a Nordic population-based case-control study.

PURPOSE: Uterine sarcomas are a rare group of uterine malignancies. Due to the low incidence and changes in uterine sarcoma classification, risk factors are not well characterized. Our objective was to evaluate risk factors for uterine sarcoma and compare risk factors between uterine sarcoma, malignant mixed Mullerian tumors (MMMTs), and type I endometrial carcinomas. METHODS: This nested case-control study utilized linked data from population-based medical birth and cancer registries in Denmark, Finland, Norway, and Sweden. Up to 10 controls were matched on country and birth year for each uterine cancer case. Using multivariable adjusted multinomial logistic regression, estimates of the associations between pregnancy-related factors and risk of uterine sarcoma, MMMTs, and type I endometrial carcinomas were determined. RESULTS: Having a very-low-birth-weight infant (< 1500 vs. 2500-3999 g: OR [95% CI] 2.83 [1.61-4.96]) was associated with an increased risk of uterine sarcoma. Whereas, having a more recent pregnancy was associated with reduced risks of MMMT (< 10 vs. ≥ 30 years: 0.66 [0.20-2.23]) and type 1 endometrial carcinomas (0.35 [0.30-0.41]) but not uterine sarcomas (1.33 [0.90-1.98], p-heterogeneity < 0.01). CONCLUSION: Our study provides evidence that risk factors for uterine sarcoma and MMMT, previously grouped with uterine sarcomas, vary substantially. Additionally, MMMT and type I endometrial carcinomas are more similar than uterine sarcoma in that pregnancy complications like gestational hypertension and preeclampsia were associated with reduced risks of both but not uterine sarcoma, suggesting different etiologies.

Maternal Health, Pregnancy and Offspring Factors, and Maternal Thyroid Cancer Risk: A Nordic Population-Based Registry Study.

Thyroid cancer incidence is higher in women than men, especially during the reproductive years, for reasons that remain poorly understood. Using population-based registry data from 4 Nordic countries through 2015, we examined associations of perinatal characteristics with risk of maternal thyroid cancer. Cases were women diagnosed with thyroid cancer ≥2 years after last birth (n = 7,425, 83% papillary). Cases were matched to controls (n = 67,903) by mother's birth year, country, and county of residence. Odds ratios (ORs) were estimated using conditional logistic regression models adjusting for parity. Older age at first pregnancy, postpartum hemorrhage (OR = 1.18, 95% (confidence interval) CI: 1.08, 1.29), and benign thyroid conditions (ORs ranging from 1.64 for hypothyroidism to 10.35 for thyroid neoplasms) were associated with increased thyroid cancer risk, as were higher offspring birth weight (per 1-kg increase, OR = 1.17, 95% CI: 1.12, 1.22) and higher likelihood of offspring being large for gestational age (OR = 1.26, 95% CI: 1.11, 1.43). Unmarried/noncohabiting status (OR = 0.91, 95% CI: 0.84, 0.98), maternal smoking (OR = 0.75, 95% CI: 0.67, 0.84), and preterm birth (OR = 0.90, 95% CI: 0.83, 0.98) were associated with reduced risk. Several factors (e.g., older age at first pregnancy, maternal smoking, goiter, benign neoplasms, postpartum hemorrhage, hyperemesis gravidarum, and neonatal jaundice) were associated with advanced thyroid cancer. These findings suggest that some perinatal exposures may influence maternal thyroid cancer risk.

In utero exposure to diethylstilbestrol and blood DNA methylation in adult women: Results from a meta-analysis of two cohort studies.

BACKGROUND: Prenatal exposure to diethylstilbestrol (DES) is associated with several adverse health outcomes. Animal studies have shown associations between prenatal DES exposure and DNA methylation. OBJECTIVE: The aim of this study was to explore blood DNA methylation in women exposed and unexposed to DES in utero. METHODS: Sixty women (40 exposed and 20 unexposed) in the National Cancer Institute's Combined DES Cohort Study and 199 women (99 exposed and 100 unexposed women) in the Sister Study Cohort were included in this analysis. Within each study, robust linear regression models were used to assess associations between DES exposure and blood DNA methylation. Study-specific associations were combined using fixed-effect meta-analysis with inverse variance weights. Our analysis focused on CpG sites located within nine candidate genes identified in animal models. We further explored whether in utero DES exposure was associated with age acceleration. RESULTS: Blood DNA methylation levels at 10 CpG sites in six of the nine candidate genes were statistically significantly associated with prenatal DES exposure (P < 0.05) in this meta-analysis. Genes included EGF, EMB, EGFR, WNT11, FOS, and TGFB1, which are related to cell proliferation and differentiation. The most statistically significant CpG site was cg19830739 in gene EGF, and it was associated with lower methylation levels in women prenatally exposed to DES compared with those not exposed (P < 0.0001; false discovery rate<0.05). The association between prenatal DES exposure in utero and age acceleration was not statistically significant (P = 0.07 for meta-analyzed results). CONCLUSIONS: There are few opportunities to investigate the effects of prenatal DES exposure. These findings suggest that in utero DES exposure may be associated with differential blood DNA methylation levels, which could mediate the increased risk of several adverse health outcomes observed in exposed women. Our findings need further evaluation using larger data sets.

Maternal autoimmune disease is not associated with cancer in the offspring.

AIM: Autoimmune disease and its medication are associated with increased cancer risk in adults, but it is unknown whether maternal autoimmune disease and/or medication use in pregnancy are associated with increased cancer risk in offspring. METHODS: In this case-control study, we identified all patients under 20 years of age with their first cancer diagnosis in 1996-2014 from the Finnish Cancer Registry (n = 2029) and 1:5 population-based controls (n = 10,103) from the Medical Birth Register. We obtained information on maternal autoimmune disease and its medication from the relevant Finnish registries and used conditional logistic regression to analyse the risk of offspring cancer after maternal autoimmune disease exposure. RESULTS: The odds ratio (OR) for cancer in offspring following maternal autoimmune exposure was 0.76 (95% confidence interval [CI] 0.47-1.23). Individual ORs for inflammatory bowel and connective tissue diseases were 1.08 (95% CI 0.56-2.01) and 0.50 (95% CI 0.23-1.08), respectively. The OR for maternal autoimmune medication was 0.95 (95% CI 0.80-1.14) overall and similar by drug subtype. There was an increased risk with medication in late pregnancy but the ORs were unstable owing to small numbers. CONCLUSION: Our study does not support an increased cancer risk among offspring of women with autoimmune disease or its medication during pregnancy.

Associations of pregnancy-related factors and birth characteristics with risk of endometrial cancer: A Nordic population-based case-control study.

Many pregnancy-related factors are associated with reduced endometrial cancer risk. However, it remains unclear whether pregnancy-related complications (e.g., hypertensive conditions) are associated with risk and whether these associations vary by endometrial cancer subtype. Thus, we evaluated the risk of endometrial cancer, overall and by subtype, in relation to pregnancy-related factors, pregnancy complications and birth characteristics. Utilizing population-based register data from four Nordic countries, we conducted a nested case-control analysis of endometrial cancer risk. We included 10,924 endometrial cancer cases and up to 10 matched controls per case. Odds ratios (ORs) with 95% confidence intervals (CIs) were derived from unconditional logistic regression models. We further evaluated associations by individual histology (i.e., endometrioid, serous, etc.) or, for rare exposures (e.g., pregnancy complications), by dualistic type (Type I [n = 10,343] and Type II [n = 581]). Preexisting and pregnancy-related hypertensive conditions were associated with increased endometrial cancer risk (OR [95% CI]: preexisting hypertension 1.88 [1.39-2.55]; gestational hypertension 1.47 [1.33-1.63]; preeclampsia 1.43 [1.30-1.58]), with consistent associations across dualistic type. Increasing number of pregnancies (≥4 vs. 1 birth: 0.64 [0.59-0.69]) and shorter time since last birth (<10 vs. ≥30 years: 0.34 [0.29-0.40]) were associated with reduced endometrial cancer risk, with consistent associations across most subtypes. Our findings support the role for both hormonal exposures and cell clearance as well as immunologic/inflammatory etiologies for endometrial cancer. This research supports studying endometrial hyperplasia, a precursor condition of endometrial cancer, in the context of pregnancy-related exposures, as this may provide insight into the mechanisms by which pregnancy affects subsequent cancer risk.

Pregnancy-related risk factors for sex cord-stromal tumours and germ cell tumours in parous women: a registry-based study.

BACKGROUND: Non-epithelial ovarian cancers are divided into sex cord-stromal tumours (SCSTs) and germ cell tumours (GCTs). Whereas parity and other pregnancy-related factors are protective for epithelial ovarian cancer, their associations with SCSTs and GCTs remains unclear. METHODS: Using data from the medical birth registries from Denmark, Finland, Norway and Sweden, we compared all parous women with a diagnosis of SCSTs (n = 420) or GCTs (n = 345) 1970-2013 with up to 10 parous controls (SCSTs n = 4041; GCTs n = 2942) matched on the cases' birth year and country. We used conditional logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) of associations between pregnancy-related factors and SCSTs and GCTs. RESULTS: The risk of SCSTs, but not GCTs, decreased with higher age at last birth [≥40 versus <25 years: OR 0.48 (95% CI 0.23-0.98)]. The risk of SCSTs (but not GCTs) also decreased with shorter time since last birth. Number of births, preterm birth, preeclampsia, and offspring size were not associated with risk of SCSTs or GCTs. CONCLUSIONS: We found a decreased risk of SCSTs with higher age at last birth and shorter time since last birth. The risk of SCSTs (but not GCTs) may be influenced by the woman's reproductive history.

Birthweight and all-cause mortality after childhood and adolescent leukemia: a cohort of children with leukemia from Denmark, Norway, Sweden, and Washington State.

Background: High birthweight may predispose children to acute lymphoid leukemia, whereas low birthweight is associated with childhood morbidity and mortality. Low and high birthweight have been inconsistently associated with mortality in children with leukemia.Material and methods: In a cohort of childhood and adolescent leukemia (0-19 years) patients from registries in Denmark, Norway, Sweden, and Washington State in the United States (1967-2015), five-year all-cause mortality was assessed by birthweight and other measures of fetal growth using the cumulative incidence function and Cox regression with adjustment for sex, diagnosis year, country, the presence of Down's syndrome or other malformations, and type of leukemia.Results: Among 7148 children and adolescents with leukemia (55% male), 4.6% were low (<2500 g) and 19% were high (≥4000 g) birthweight. Compared with average weight, hazard ratios (HRs) of death associated with low birthweight varied by age at leukemia diagnosis: 1.5 (95% confidence interval (CI): 0.7, 3.2) for patients 0-1 year old, 1.6 (95% CI: 1.0, 2.6) for >1-2 years old; 1.0 (95% CI: 0.6, 1.5) for 3-8 years old; 1.0 (95% CI: 0.6, 1.8) for 9-13 years old; and 1.2 (95% CI: 0.7, 2.1) for 14-19 years old, and were similar for size for gestational age and Ponderal index. In analyses restricted to children born full term (37-41 weeks of gestation), results were only slightly attenuated but risk was markedly increased for infants aged ≤1 year (HR for low birthweight = 3.2, 95% CI: 1.2, 8.8).Conclusion: This cohort study does not suggest that low birthweight or SGA is associated with increased five-year all-cause mortality risk among children with any type of childhood leukemia or acute lymphoblastic leukemia, specifically, beyond infancy.

Gender Identity and Sexual Orientation Identity in Women and Men Prenatally Exposed to Diethylstilbestrol.

We assessed the associations of prenatal diethylstilbestrol (DES) exposure, a potent estrogen, with sexual orientation and gender identity in 3306 women and 1848 men who participated in a study of prenatal DES exposure. Odds ratios (OR) and 95% confidence intervals (CI) were derived from logistic regression models adjusted for birth year, study cohort, and education. Among women, the OR for DES in relation to reporting sexual orientation identity as nonheterosexual was 0.61 (95% CI 0.40-0.92) primarily due to a strong inverse association with a lesbian identity (OR 0.44, 95% CI 0.25-0.76). Among men, the OR for DES in relation to reporting a nonheterosexual sexual orientation identity was 1.4 (95% CI 0.82-2.4), and ORs were similar for having a gay identity (1.4, 95% CI 0.72-2.85) and bisexual identity (1.4, 95% CI 0.57-3.5). Only five individuals reported a gender identity not conforming to that assigned at birth, preventing meaningful analysis. Women who were prenatally exposed to DES were less likely to have a lesbian or bisexual orientation, while DES-exposed men were somewhat more likely to report being gay or bisexual, but estimates were imprecise.

Pubertal timing and breast density in young women: a prospective cohort study.

BACKGROUND: Earlier age at onset of pubertal events and longer intervals between them (tempo) have been associated with increased breast cancer risk. It is unknown whether the timing and tempo of puberty are associated with adult breast density, which could mediate the increased risk. METHODS: From 1988 to 1997, girls participating in the Dietary Intervention Study in Children (DISC) were clinically assessed annually between ages 8 and 17 years for Tanner stages of breast development (thelarche) and pubic hair (pubarche), and onset of menses (menarche) was self-reported. In 2006-2008, 182 participants then aged 25-29 years had their percent dense breast volume (%DBV) measured by magnetic resonance imaging. Multivariable, linear mixed-effects regression models adjusted for reproductive factors, demographics, and body size were used to evaluate associations of age and tempo of puberty events with %DBV. RESULTS: The mean (standard deviation) and range of %DBV were 27.6 (20.5) and 0.2-86.1. Age at thelarche was negatively associated with %DBV (p trend = 0.04), while pubertal tempo between thelarche and menarche was positively associated with %DBV (p trend = 0.007). %DBV was 40% higher in women whose thelarche-to-menarche tempo was 2.9 years or longer (geometric mean (95%CI) = 21.8% (18.2-26.2%)) compared to women whose thelarche-to-menarche tempo was less than 1.6 years (geometric mean (95%CI) = 15.6% (13.9-17.5%)). CONCLUSIONS: Our results suggest that a slower pubertal tempo, i.e., greater number of months between thelarche and menarche, is associated with higher percent breast density in young women. Future research should examine whether breast density mediates the association between slower tempo and increased breast cancer risk.

Maternal reproductive hormones and angiogenic factors in pregnancy and subsequent breast cancer risk.

PURPOSE: Breast cancer risk associated with pregnancy characteristics may be mediated by maternal hormones or angiogenic factors. METHODS: We conducted a prospective breast cancer case-control study among women in the Avon Longitudinal Study of Parents and Children (ALSPAC) and Norwegian Mother and Child Cohort Study (MoBa) related to maternal pregnancy prolactin (n = 254 cases and 374 controls), placental growth factor (PlGF, n = 252 and 371), soluble fms-like tyrosine kinase-1 (sFlt-1, n = 118 and 240) and steroid hormone concentrations (ALSPAC only, n = 173 and 171). Odds ratios (OR) and 95% confidence intervals (CI) for a 1 SD change in analytes were estimated using unconditional logistic regression with matching factors (cohort, mother's birth year, serum/plasma, blood collection timing) and gestational age. RESULTS: Breast cancer ORs (95% CI) were 0.85 (0.51-1.43) for estradiol, 0.86 (0.67-1.09) for testosterone, 0.89 (0.71-1.13) for androstenedione, 0.97 (0.71-1.34) for hCG, 0.93 (0.75, 1.15) for prolactin, 1.00 (0.78-1.27) for PlGF and 1.91 (1.00-3.65 ALSPAC) and 0.94 (0.73-1.21 MoBa) for sFlt-1, and were similar adjusting for potential confounders. Results were similar by blood collection timing, parity, age at first birth or diagnosis, and time between pregnancy and diagnosis. CONCLUSION: These data do not provide strong evidence of associations between maternal hormones or angiogenic factors with subsequent maternal breast cancer risk.

Prenatal Diethylstilbestrol Exposure and Risk of Depression in Women and Men.

BACKGROUND: Prenatal exposure to diethylstilbestrol (DES), an endocrine-disrupting chemical, may be associated with depression in adulthood, but previous findings are inconsistent. METHODS: Women (3,888 DES exposed and 1,729 unexposed) and men (1,021 DES exposed and 1,042 unexposed) participating in the National Cancer Institute (NCI) DES Combined Cohort Follow-up Study were queried in 2011 for any history of depression diagnosis or treatment. Hazard ratios (HRs; 95% confidence intervals [CIs]) estimated the associations between prenatal DES exposure and depression risk. RESULTS: Depression was reported by 993 (26%) exposed and 405 (23%) unexposed women, and 177 (17%) exposed and 181 (17%) unexposed men. Compared with the unexposed, HRs for DES and depression were 1.1 (95% CI = 0.9, 1.2) in women and 1.0 (95% CI = 0.8, 1.2) in men. For medication-treated depression, the HRs (CIs) were 1.1 (0.9, 1.2) in women and 0.9 (0.7, 1.2) in men. In women, the HR (CI) for exposure to a low cumulative DES dose was 1.2 (1.0, 1.4), and for DES exposure before 8 weeks' gestation was 1.2 (1.0, 1.4). In men, the HR for low dose was 1.2 (95% CI = 0.9, 1.6) and there was no association with timing. In women, associations were uninfluenced by the presence of DES-related vaginal epithelial changes or a prior diagnosis of DES-related adverse outcomes. CONCLUSIONS: Prenatal DES exposure was not associated overall with risk of depression in women or men. In women, exposure in early gestation or to a low cumulative dose may be weakly associated with an increased depression risk.

Prenatal diethylstilbestrol exposure and mammographic density.

In a prospective cohort study of the health effects associated with prenatal Diethylstilbestrol (DES) exposure, DES was associated with an increased breast cancer risk after 40 years of age. It is unknown whether it is associated with greater mammographic density, which strongly predicts breast cancer risk. A cohort of DES-exposed and unexposed women was assembled at the Mayo Clinic in 1975, and followed through 2012 as part of the National Cancer Institute's DES follow-up study. Mammographic density from 3,637 mammograms for 332 (222 DES-exposed, 110 unexposed) women in this cohort screened at the Mayo Clinic, Rochester between 1996 and 2015 was determined clinically using the Breast Imaging Reporting and Data System (BI-RADS). Any effect of prenatal DES exposure on mammographic density was estimated using repeated measures logistic regression. There was no association between prenatal DES exposure and high mammographic density for either premenopausal [Odds ratios (OR) = 0.92 (95% Confidence Interval (CI): 0.50, 1.7] or postmenopausal women (OR = 0.90; 95% CI: 0.54, 1.5). Among premenopausal women, associations differed by body mass index (BMI), with ORs of 1.47 (0.70, 3.1) for women with BMI above the median and 0.53 (0.23, 1.3) for those with BMI below the median (pinteraction = 0.05). Overall, however, prenatal DES exposure was not associated with high mammographic density in this sample of DES Study participants. Consequently, this study does not provide evidence that high mammographic density is involved with the influence of DES on breast cancer risk.

Pregnancy complications and subsequent breast cancer risk in the mother: a Nordic population-based case-control study.

Certain features of pregnancy are important risk factors for breast cancer, such as protection afforded by young age at first birth. Preeclampsia, a pregnancy complication, is associated with reduced maternal breast cancer risk. However, questions remain regarding causality, biological mechanisms and the relation of other hypertensive conditions to risk. We conducted a population-based case-control study of breast cancer cases (n = 116,196) in parous women identified through linkage of birth and cancer registries in Denmark, Finland, Norway and Sweden (1967-2013), including up to 10 matched controls per case (n = 1,147,192) sampled from the birth registries (complete data were not available on all variables). Odds ratios (ORs) with 95% confidence intervals (CIs) were derived from unconditional logistic regression models including matching factors (country, maternal birth year) and parity. Hypertension diagnosed before pregnancy (OR 0.87; 95% CI 0.78-0.97), gestational hypertension (OR 0.90; 95% CI 0.86-0.93) and preeclampsia (OR 0.91; 95% CI 0.88-0.95) were associated with reduced breast cancer risk. Results remained similar after adjustment for smoking and maternal body mass index before first pregnancy, and were generally similar stratified by parity, age at breast cancer diagnosis, time since first and last birth, sex of the offspring and calendar time. Except for retained placenta (OR 1.14; 95% CI 0.98-1.32), no other pregnancy complication appeared associated with breast cancer risk. The mechanisms mediating the modest risk reductions for history of preeclampsia or hypertension preceding or arising during pregnancy, and possible increased risk with history of retained placenta are unknown and warrant further laboratory, clinical and epidemiological investigation.

Preterm delivery is associated with an increased risk of epithelial ovarian cancer among parous women.

Epithelial ovarian cancer is a fatal disease of largely unknown etiology. Higher parity is associated with reduced risk of ovarian cancer. However, among parous women, the impact of pregnancy-related factors on risk is not well understood. This population-based case-control study included all parous women with epithelial ovarian cancer in Denmark, Finland, Norway and Sweden during 1967-2013 (n = 10,957) and up to 10 matched controls (n = 107,864). We used conditional logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for pregnancy-related factors and ovarian cancer risk by histological subtype. Preterm delivery was associated with an increased risk [pregnancy length (last pregnancy) ≤30 vs. 39-41 weeks, OR 1.33 (95% CI 1.06-1.67), adjusted for number of births]; the OR increased as pregnancy length decreased (p for trend < 0.001). Older age at first and last birth was associated with a decreased risk [first birth: 30-39 vs. <25 years: adjusted OR 0.76 (95% CI 0.70-0.83); last birth 30-39 vs. <25 years: adjusted OR 0.76 (95% CI 0.71-0.82)]. Increasing number of births was protective [≥4 births vs. 1; OR 0.63 (95% CI 0.59-0.68)] for all subtypes, most pronounced for clear-cell tumors [OR 0.30, (95% CI 0.21-0.44), pheterogeneity < 0.001]. No associations were observed for multiple pregnancies, preeclampsia or offspring size. In conclusion, in addition to high parity, full-term pregnancies and pregnancies at older ages were associated with decreased risk of ovarian cancer. Our findings favor the cell clearance hypothesis, i.e. a recent pregnancy provides protection by clearing of precancerous cells from the epithelium of the ovary/fallopian tubes, mediated by placental or ovarian hormones.

Reproductive history and risk of colorectal adenocarcinoma in parous women: a Nordic population-based case-control study.

BACKGROUND: Data are conflicting regarding the role of endogenous sex hormones in colorectal carcinogenesis. In this large population-based study, we pooled data from birth and cancer registries in four Nordic countries, to evaluate the risk of colorectal adenocarcinoma in relation to women's reproductive history. METHODS: We conducted a population-based case-control study among women registered in Nordic birth registries. The study included colorectal adenocarcinoma cases diagnosed in Denmark, Finland, Norway, and Sweden during 1967-2013 and up to 10 matched controls per case, in total 22 185 cases and 220 246 controls. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were derived from conditional logistic regression models. We had limited information available on possible confounders. RESULTS: We found no evidence for associations between colorectal adenocarcinoma and parity, age at first and last birth, and time since first and last birth. The risk estimates were also close to unity for specific cancer subsites (proximal and distal colon and rectum). As well, when the analyses were stratified on menopausal status, parity, and mother's year of birth, no indication of associations was found. CONCLUSIONS: In this large, Nordic population-based study, no evidence for associations was found between women's reproductive history and colorectal adenocarcinoma in parous women.

A prospective study of angiogenic markers and postmenopausal breast cancer risk in the prostate, lung, colorectal, and ovarian cancer screening trial.

PURPOSE: Pro-angiogenic factors are positively associated with breast tumor staging and poorer prognosis, but their role in the etiology of breast cancer has not been assessed. METHODS: We measured serum levels of the pro-angiogenic vascular endothelial growth factor A (VEGF), and placental growth factor (PlGF) and anti-angiogenic soluble fms-like tyrosine kinase-1 (sFlt-1) in 352 incident breast cancer cases [mean age at diagnosis 67 (range 55-83)] and 352 non-cases in the prostate, lung, colorectal, and ovarian screening trial (women enrolled 1993-2001, followed through 2005) matched on age and date of enrollment. Cases were followed on average 4.2 years from blood draw to diagnosis, range 3.9-12.8 years; 53 % were estrogen receptor positive/progesterone receptor positive (ER+/PR+), and 13 % were ER-/PR-. Quartile-specific hazard ratios (HR) and 95 % confidence intervals (CI) were estimated using weighted Cox proportional hazards regression models adjusted for known breast cancer risk factors. An ordinal variable for the angiogenic markers was used to test for trend in the HR. RESULTS: Comparing the highest to lowest quartile, multivariable HR were 0.90 for VEGF (95 % CI 0.33-2.43, p trend = 0.88), 1.38 for sFlt-1 (95 % CI 0.63-3.04, p trend = 0.63), and 0.62 for PlGF (95 % CI 0.19-2.00, p trend = 0.73). Risk patterns were not altered when all angiogenic markers were included in the model simultaneously, or by restricting analyses to invasive breast cancers, to cases diagnosed two or more years after blood collection or to ER+ tumors. CONCLUSIONS: There was no evidence of an increased breast cancer risk associated with circulating levels of pro-angiogenic markers VEGF and PlGF or a reduced risk with circulating levels of anti-angiogenic marker sFlt-1.

Prenatal diethylstilbestrol exposure and high-grade squamous cell neoplasia of the lower genital tract.

BACKGROUND: Prenatal diethylstilbestrol (DES) exposure is associated with an excess risk of clear-cell adenocarcinoma of the vagina and cervix, and of high-grade squamous neoplasia. OBJECTIVE: We explored whether neoplasia risk remains elevated among DES-exposed women as they age. STUDY DESIGN: In all, 4062 DES-exposed and 1837 unexposed daughters were followed for approximately 30 years (1982 through 2013) for pathology-confirmed diagnoses of cervical intraepithelial neoplasia grade ≥2 (CIN2+) of the lower genital tract (n = 178). Hazard ratios (HR) and 95% confidence intervals (CI) were estimated adjusting for birth year and individual study cohort. RESULTS: The cumulative incidence of CIN2+ in the DES-exposed group was 5.3% (95% CI, 4.1-6.5%) and in the unexposed group was 2.6% (95% CI, 1.5-3.7%). The HR for DES and CIN2+ was 1.98 (95% CI, 1.33-2.94), and was similar with further adjustment for frequency of cervical cancer screening (HR, 1.97; 95% CI, 1.33-2.93). The HR was 2.10 (95% CI, 1.41-3.13) with additional adjustment for other potential confounders. The HR for DES exposure was elevated through age 44 years (age <45 years HR, 2.47; 95% CI, 1.55-3.94), but not in women age ≥45 years (HR, 0.91; 95% CI, 0.39-2.10). In exposed women, HRs for DES were 1.74 (95% CI, 1.09-2.79) among those who had earlier evidence of vaginal epithelial changes (VEC), presumably reflecting glandular epithelium undergoing transformation to normal, adult-type squamous epithelium, and 1.24 (95% CI, 0.75-2.06) among those without VEC, compared with unexposed women. The HRs for DES and CIN2+ were higher among women with earlier intrauterine exposure (HR, 2.64; 95% CI, 1.64-4.25 for <8 weeks' gestation and HR, 1.41; 0.88-2.25 for ≥8 weeks' gestation), and lowest when exposure began >15th week (HR, 1.14; 95% CI, 0.59-2.20). CONCLUSION: CIN2+ incidence was higher among the DES exposed, particularly those with early gestational exposure and VEC. The HR for DES and CIN2+ remained positive and significant until the mid-40s, confirming that the recommendation of annual cytological screening among these women is appropriate. Whether those ≥45 years of age continue to require increased screening is unclear, and would require a careful weighing of possible risks and benefits.

Hyperemesis gravidarum and maternal cancer risk, a Scandinavian nested case-control study.

Reproductive factors have been shown to influence cancer risk. Several pathological conditions during pregnancy have also been associated with subsequent altered cancer risk in the mother. Hyperemesis gravidarum (hyperemesis) is an early pregnancy condition characterized by severe nausea and vomiting resulting in weight loss and metabolic disturbances. Studies have reported associations between hyperemesis and cancer, but results are inconsistent. In this nested case-control study we linked the population-based medical birth registries and cancer registries in Norway, Sweden and Denmark in order to examine overall cancer risk and risk of specific cancer types in women with a history of hyperemesis, using conditional logistic regression. In total, 168,501 cases of cancer in addition to up to 10 cancer-free controls per case were randomly sampled, matched on year of birth and birth registry (n = 1,721,626). Hyperemesis was defined through the International Classification of Diseases. Analyses were adjusted for potential confounders. Hyperemesis was inversely associated with overall cancer risk with adjusted relative risk (aRR) of 0.93 (95% CI: 0.88-0.99), with cancer in the lungs (aRR: 0.60, 95% CI: 0.44-0.81), cervix (aRR: 0.66, 95% CI: 0.49-0.91) and rectum (aRR: 0.48, 95% CI: 0.29-0.78). Thyroid cancer was positively associated with hyperemesis (aRR 1.45, 95% CI: 1.06-1.99) and risk increased with more than one hyperemetic pregnancy (aRR 1.80, 95% CI: 1.23-2.63). Hormonal factors, in particular human chorionic gonadotropin, are likely to be involved in mediating these effects. This study is the first to systematically address these associations and provides valuable knowledge on potential long-term consequences of hyperemesis.

Hyperemesis gravidarum and risk of cancer in offspring, a Scandinavian registry-based nested case-control study.

BACKGROUND: Hyperemesis gravidarum is a serious condition affecting 0.8-2.3% of pregnant women and can be regarded as a restricted period of famine. Research concerning potential long-term consequences of the condition for the offspring, is limited, but lack of nutrition in-utero has been associated with chronic disease in adulthood, including some cancers. There is growing evidence that several forms of cancer may originate during fetal life. We conducted a large study linking the high-quality population-based medical birth- and cancer registries in Norway, Sweden and Denmark, to explore whether hyperemesis is associated with increased cancer risk in offspring. METHODS: A registry-based nested case-control study. Twelve types of childhood cancer were selected; leukemia, lymphoma, cancer of the central nervous system, testis, bone, ovary, breast, adrenal and thyroid gland, nephroblastoma, hepatoblastoma and retinoblastoma. Conditional logistic regression models were applied to study associations between hyperemesis and risk of childhood cancer, both all types combined and separately. Cancer types with five or more exposed cases were stratified by age at diagnosis. All analysis were adjusted for maternal age, ethnicity and smoking, in addition to the offspring's Apgar score, placental weight and birth weight. Relative risks with 95% confidence intervals were calculated. RESULTS: In total 14,805 cases and approximately ten controls matched on time, country of birth, sex and year of birth per case (147,709) were identified. None of the cancer types, analyzed combined or separately, revealed significant association with hyperemesis. When stratified according to age at diagnosis, we observed a RR 2.13 for lymphoma among adolescents aged 11-20 years ((95% CI 1.14-3.99), after adjustment for maternal ethnicity and maternal age, RR 2.08 (95% CI 1.11-3.90)). The finding was not apparent when a stricter level of statistical significance was applied. CONCLUSIONS: The main finding of this paper is that hyperemesis does not seem to increase cancer risk in offspring. The positive association to lymphoma may be by chance and needs confirmation.