Circulating endogenous sex steroids and risk of differentiated thyroid carcinoma in men and women.

Thyroid cancer (TC) is substantially more common in women than in men, pointing to a possible role of sex steroid hormones. We investigated the association between circulating sex steroid hormones, sex hormone binding globulin (SHBG) and the risk of differentiated TC in men and women within the European Prospective Investigation into Cancer and nutrition (EPIC) cohort. During follow-up, we identified 333 first primary incident cases of differentiated TC (152 in pre/peri-menopausal women, 111 in post-menopausal women, and 70 in men) and 706 cancer-free controls. Women taking exogenous hormones at blood donation were excluded. Plasma concentrations of testosterone, androstenedione, dehydroepiandrosterone, estradiol, estrone and progesterone (in pre-menopausal women only) were performed using liquid chromatography/mass spectrometry method. SHBG concentrations were measured by immunoassay. Odds ratios (ORs) were estimated using conditional logistic regression models adjusted for possible confounders. No significant associations were observed in men and postmenopausal women, while a borderline significant increase in differentiated TC risk was observed with increasing testosterone (adjusted OR T3 vs T1: 1.68, 95% CI: 0.96-2.92, ptrend = .06) and androstenedione concentrations in pre/perimenopausal women (adjusted OR T3 vs T1: 1.78, 95% CI: 0.96-3.30, ptrend = .06, respectively). A borderline decrease in risk was observed for the highest progesterone/estradiol ratio (adjusted OR T3 vs T1: 0.54, 95% CI: 0.28-1.05, ptrend = .07). Overall, our results do not support a major role of circulating sex steroids in the etiology of differentiated TC in post-menopausal women and men but may suggest an involvement of altered sex steroid production in pre-menopausal women.

Compliance with public health recommendations of cancer-free female research volunteers: the French Seintinelles study.

PURPOSE: Acting on modifiable risk factors can prevent approximately 40% of cancers. Knowing the factors that lead people to adopt healthy behaviors is crucial for designing effective primary prevention campaigns. Our study attempts to provide knowledge in this direction. METHODS: This cross-sectional study was conducted via the Seintinelles collaborative research platform in a community of women without a personal cancer history, and volunteering to take online questionnaires. We collected data on sociodemographic and health factors, knowledge of cancer risk factors, behaviors, and possible behavior changes (tobacco/alcohol use, diet, body weight, and physical activity) in the last 10 years. RESULTS: The study involved 1465 women aged between 18 and 84 years. Factors such as young age, living alone, and obesity were associated with some positive or negative behavior changes. Being professionally active and having comorbidities favored certain positive behavior changes, while having dependent children, living in a rural area, and being hospitalized were associated with negative or no change in behaviors. Lack of knowledge about modifiable risk factors for cancer was associated with the non-adoption of various healthy behaviors (consumptions of fruit and vegetables, processed and red meat; physical activity). Only 5.5% of participants currently reported to be compliant with seven public health recommendations (smoking; alcohol, fruit/vegetables, and red/processed meat intakes; body mass index; and physical activity). CONCLUSIONS: This study allowed to identify the need to increase the level of knowledge on modifiable risk factors for cancer among the general population and to better clarify the content of prevention messages.

Quality of life among French breast cancer survivors in comparison with cancer-free women: the Seintinelles study.

BACKGROUND: Health-Related Quality of life (HRQoL) in cancer survivors can be significantly affected in the long-term by various consequences resulting from differing levels of severity of cancer and its treatments. Our objective was to identify factors associated with HRQoL in breast cancer survivors (BCSs) and cancer-free women (CFWs). METHODS: We conducted a cross-sectional study in Seintinelles volunteers who answered online questionnaires between September 15, 2020 and February 5, 2021. HRQoL was measured using the World Health Organization Quality of Life-BREF questionnaire. We collected data on sociodemographic and health-related factors, lifestyle habits, coping mechanisms, locus of control, and health literacy. SAS version 9.4 statistical software was used for analyses. We performed descriptive analyses of the characteristics of the participants in each group and compared these characteristics between the two groups using the Chi2 test or the Student t-test. The adjusted means of the scores of different psychometric scales were calculated and compared using the method of least squares to fit general linear models (GLM) while adjusting for various factors. Multiple linear or multiple logistic regression models were used to assess the factors associated with WHOQOL-BREF scores, separately, in the two groups of participants. RESULTS: The study involved 722 BCSs and 1359 CFWs aged 26-75 years. BCSs had significantly lower physical health scores and were less likely to be satisfied with their health compared to CFWs (59.5 vs. 63.2, p < 0.0001; and 56.5% vs. 75.2%, p = 0.002, respectively). In both groups, some common factors were positively associated with physical health (high financial level, being professionally active, normal BMI, good health status, alcohol consumption, higher values (> 22) of internal locus of control); or inversely associated (neurological and sleep problems, over two medical consultations/year). In BCSs, treatment by mastectomy or radiation therapy/brachytherapy, a short-time since diagnosis, current cancer therapy, and presence of sequalae were inversely associated with physical health. BCSs' health satisfaction was diminished with lower values of coping by positive thinking (≤ 14) and seeking social support (≤ 18). CONCLUSIONS: HRQoL can be improved by developing strategies that increase internal locus of control and coping (positive thinking, problem-solving and seeking social support), and through health literacy.

Baseline and lifetime alcohol consumption and risk of skin cancer in the European Prospective Investigation into Cancer and Nutrition cohort (EPIC).

Experimental evidence suggests that alcohol induces cutaneous carcinogenesis, yet epidemiological studies on the link between alcohol intake and skin cancer have been inconsistent. The European Prospective Investigation into Cancer and Nutrition (EPIC) is a prospective cohort initiated in 1992 in 10 European countries. Alcohol intake at baseline and average lifetime alcohol intake were assessed using validated country-specific dietary and lifestyle questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated in Cox models. A total of 14 037 skin cancer cases (melanoma: n = 2457; basal-cell carcinoma (BCC): n = 8711; squamous-cell carcinoma (SCC): n = 1928; unknown: n = 941) were identified among 450 112 participants (average follow-up: 15 years). Baseline alcohol intake was positively associated with SCC (>15 vs 0.1-4.9 g/day: HR = 1.44, 95% CI = 1.17-1.77; Ptrend  = .001), BCC (HR = 1.12, 95% CI = 1.01-1.23; Ptrend  = .04), and melanoma risks in men (HR = 1.17, 95% CI = 0.95-1.44; Ptrend  = .17), while associations were more modest in women (SCC: HR = 1.09, 95% CI = 0.90-1.30; Ptrend  = .13; BCC: HR = 1.08, 95% CI = 1.00-1.17, Ptrend  = .03; melanoma: HR = 0.93, 95% CI = 0.80-1.08, Ptrend  = .13). Associations were similar for lifetime alcohol intake, with an attenuated linear trend. Lifetime liquor/spirit intake was positively associated with melanoma (fourth vs first quartile: HR = 1.47, 95% CI = 1.08-1.99; Ptrend  = .0009) and BCC risks in men (HR = 1.17, 95% CI = 1.04-1.31; Ptrend  = .14). Baseline and lifetime intakes of wine were associated with BCC risk (HR = 1.25 in men; HR = 1.11-1.12; in women). No statistically significant associations were found between beverage types and SCC risk. Intake of beer was not associated with skin cancer risk. Our study suggests positive relationships between alcohol intake and skin cancer risk, which may have important implications for the primary prevention of skin cancer.

Circulating vitamin D and breast cancer risk: an international pooling project of 17 cohorts.

Laboratory and animal research support a protective role for vitamin D in breast carcinogenesis, but epidemiologic studies have been inconclusive. To examine comprehensively the relationship of circulating 25-hydroxyvitamin D [25(OH)D] to subsequent breast cancer incidence, we harmonized and pooled participant-level data from 10 U.S. and 7 European prospective cohorts. Included were 10,484 invasive breast cancer cases and 12,953 matched controls. Median age (interdecile range) was 57 (42-68) years at blood collection and 63 (49-75) years at breast cancer diagnosis. Prediagnostic circulating 25(OH)D was either newly measured using a widely accepted immunoassay and laboratory or, if previously measured by the cohort, calibrated to this assay to permit using a common metric. Study-specific relative risks (RRs) for season-standardized 25(OH)D concentrations were estimated by conditional logistic regression and combined by random-effects models. Circulating 25(OH)D increased from a median of 22.6 nmol/L in consortium-wide decile 1 to 93.2 nmol/L in decile 10. Breast cancer risk in each decile was not statistically significantly different from risk in decile 5 in models adjusted for breast cancer risk factors, and no trend was apparent (P-trend = 0.64). Compared to women with sufficient 25(OH)D based on Institute of Medicine guidelines (50- < 62.5 nmol/L), RRs were not statistically significantly different at either low concentrations (< 20 nmol/L, 3% of controls) or high concentrations (100- < 125 nmol/L, 3% of controls; ≥ 125 nmol/L, 0.7% of controls). RR per 25 nmol/L increase in 25(OH)D was 0.99 [95% confidence intervaI (CI) 0.95-1.03]. Associations remained null across subgroups, including those defined by body mass index, physical activity, latitude, and season of blood collection. Although none of the associations by tumor characteristics reached statistical significance, suggestive inverse associations were seen for distant and triple negative tumors. Circulating 25(OH)D, comparably measured in 17 international cohorts and season-standardized, was not related to subsequent incidence of invasive breast cancer over a broad range in vitamin D status.

Endometriosis, Psoriasis, and Psoriatic Arthritis: A Prospective Cohort Study.

Endometriosis, psoriasis, and psoriatic arthritis (PsA) are chronic inflammatory disorders whose etiologies remain poorly understood but may be correlated, as endometriosis has been associated with other inflammatory disorders. We investigated the bidirectional associations between laparoscopically confirmed endometriosis and physician-diagnosed psoriasis and PsA in the Nurses' Health Study II cohort (n = 116,429, United States, 1991-2013). We confirmed 4,112 incident cases of laparoscopically confirmed endometriosis (mean age at diagnosis = 40.3 years) and 697 validated physician-diagnosed cases of psoriasis (mean age at diagnosis = 43.6 years), 110 of which presented with concomitant PsA. A history of psoriasis with concomitant PsA was associated with a 2-fold higher risk of endometriosis (hazard ratio (HR) = 2.01, 95% CI: 1.23, 3.30); however, no association was observed between psoriasis without PsA and endometriosis risk (HR = 0.93, 95% CI: 0.68, 1.26). When endometriosis was the exposure, it was not associated with a risk of subsequent psoriasis (HR = 1.28, 95% CI: 0.95, 1.72). The risk of psoriasis with PsA was notably higher; however, the sample size was small and the confidence intervals wide (HR = 1.77, 95% CI: 0.89, 3.52). Our findings suggest that psoriasis with concomitant PsA is associated with greater risk of laparoscopically confirmed endometriosis. In addition, there was a suggestive association between endometriosis diagnosis and subsequent risk of psoriasis with PsA.

Circulating inflammatory biomarkers, adipokines and breast cancer risk-a case-control study nested within the EPIC cohort.

BACKGROUND: Inflammation has been hypothesized to play a role in the development and progression of breast cancer and might differently impact breast cancer risk among pre and postmenopausal women. We performed a nested case-control study to examine whether pre-diagnostic circulating concentrations of adiponectin, leptin, c-reactive protein (CRP), tumour necrosis factor-α, interferon-γ and 6 interleukins were associated with breast cancer risk, overall and by menopausal status. METHODS: Pre-diagnostic levels of inflammatory biomarkers were measured in plasma from 1558 case-control pairs from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. We used conditional logistic regression to estimate the odds ratios (ORs) of breast cancer at blood collection, per one standard deviation increase in biomarker concentration. RESULTS: Cases were diagnosed at a mean age of 61.4 years on average 8.6 years after blood collection. No statistically significant association was observed between inflammatory markers and breast cancer risk overall. In premenopausal women, borderline significant inverse associations were observed for leptin, leptin-to-adiponectin ratio and CRP [OR= 0.89 (0.77-1.03), OR= 0.88 (0.76-1.01) and OR= 0.87 (0.75-1.01), respectively] while positive associations were observed among postmenopausal women [OR= 1.16 (1.05-1.29), OR= 1.11 (1.01-1.23), OR= 1.10 (0.99-1.22), respectively]. Adjustment for BMI strengthened the estimates in premenopausal women [leptin: OR = 0.83 (0.68-1.00), leptin-to-adiponectin ratio: OR = 0.80 (0.66-0.97), CRP: OR = 0.85 (0.72-1.00)] but attenuated the estimates in postmenopausal women [leptin: OR = 1.09 (0.96-1.24), leptin-to-adiponectin ratio: OR = 1.02 (0.89-1.16), CRP: OR = 1.04 (0.92-1.16)]. CONCLUSIONS: Associations between CRP, leptin and leptin-to-adiponectin ratio with breast cancer risk may represent the dual effect of obesity by menopausal status although this deserves further investigation.

Dietary antioxidant supplements and risk of keratinocyte cancers in women: a prospective cohort study.

PURPOSE: Experimental studies suggested that antioxidants could protect against skin carcinomas. However, epidemiological studies on antioxidant supplement use in relation to basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC) risks yielded inconsistent findings, and few prospective studies have been conducted to date. We aimed to investigate the associations between antioxidant supplement intake and keratinocyte cancer (KC) risk. METHODS: E3N is an ongoing prospective cohort initiated in 1990 and involving 98,995 French women aged 40-65 years at recruitment. Intakes of dietary antioxidants were estimated via a validated dietary questionnaire in 1993 and self-reported antioxidant supplement use was collected in 1995. We used Cox models to compute hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for age and skin cancer risk factors. RESULTS: Over 1995-2014, 2426 BCC and 451 SCC cases were diagnosed among 63,063 women. We found positive relationships between vitamin A supplement use and KC risk (HR = 1.37, 95% CI 1.15-1.62), particularly with BCC (HR = 1.40, 95% CI 1.17-1.69); and between vitamin E supplement use and risks of both BCC (HR = 1.21, 95% CI 1.03-1.52) and SCC (HR = 1.43, 95% CI 1.03-1.99). Intake of beta-carotene supplements was associated with an increased SCC risk (HR = 1.59, 95% CI 1.00-2.54). Vitamin C supplement use was not associated with KC risk. We found similar results when considering total antioxidant intake. CONCLUSIONS: Intakes of vitamin A or E supplements were associated with an increased KC risk in women. Further studies with information on doses and duration of supplement use and the ability to examine their underlying mechanisms are needed.

Associations between plasma levels of brominated flame retardants and methylation of DNA from peripheral blood: A cross-sectional study in a cohort of French women.

BACKGROUND: Brominated flame retardants (BFRs) are organic compounds that are widespread in the environment. Because of their persistence, they are able to bioaccumulate with major impacts on human health. It has been hypothesized that the effect of BFRs on human health is mediated by alterations of DNA methylation. OBJECTIVE: The aim of this study was to examine the association between methylation of DNA extracted from peripheral blood and circulating levels of BFRs measured in plasma. METHODS: We conducted a methylation wide association study on 336 blood samples from a study within the E3N (Etude Epidémiologique auprès de femmes de l'Education Nationale) cohort, a long-term longitudinal cohort of French women. DNA methylation at more than 850 000 cytosine-guanine dinucleotide (CpG) sites was measured with the Illumina Infinium HumanMethylation - EPIC BeadChip. Circulating levels of seven BFRs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and PBB-153) were measured by gas chromatography coupled to high-resolution mass spectrometry in plasma samples. The association between DNA methylation and BFRs plasma levels was assessed through linear mixed-effects models followed by gene-set enrichment analyses (GSEA). RESULTS: We identified 253 CpG sites whose methylation levels were significantly associated with exposure to BFRs after Bonferroni correction. For 50 of these CpGs the p-values were less than 2.2x10-9 with the strongest association being between BDE-154 and cg23619365 (4.32x10-13). GSEA of CpG sites associated with exposure to BFRs identified significant enrichment of genes involved in hypoxia, glycolysis and adipogenesis. CONCLUSIONS: Exposure to BFRs appears to be related to numerous alterations in DNA methylation. These findings, if replicated in independent studies, provide insights into the biological and health effects of BFRs.

Recreational and residential sun exposure and risk of endometriosis: a prospective cohort study.

STUDY QUESTION: Is recreational and residential sun exposure associated with risk of endometriosis? SUMMARY ANSWER: Tanning bed use in early adulthood, sunscreen use and history of sunburns were associated with a greater risk of endometriosis; however, higher residential UV exposure was associated with a lower endometriosis risk. WHAT IS KNOWN ALREADY: Previous research has reported an association between endometriosis and skin cancer, with evidence of shared risk factors between the two diseases. We investigated the potential associations between ultraviolet radiation and endometriosis risk. STUDY DESIGN, SIZE, DURATION: The Nurses' Health Study II is a prospective cohort of 116 429 female US nurses aged 25-42 years at enrolment in 1989. Participants completed self-administered biennial questionnaires through June 2015. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: We investigated self-reported measures of recreational sun-exposure and geocoded residential UV exposure in childhood and adulthood in relation to risk of laparoscopically confirmed endometriosis among premenopausal white women. We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% CIs. MAIN RESULTS AND THE ROLE OF CHANCE: During follow-up, 4791 incident cases of laparoscopically confirmed endometriosis were reported among 1 252  248 person-years. Tanning bed use during high school/college (≥6 times per year vs. never use: HR = 1.19, 95% CI = 1.01-1.40; Ptrend = 0.04) and at ages 25-35 (HR = 1.24, 95% CI = 1.12-1.39; Ptrend ≤ 0.0001), number of sunburns during adolescence (Ptrend = 0.03) and percentage of time using sunscreen in adulthood (Ptrend = 0.002) were positively associated with risk of endometriosis. In contrast, residential UV level at birth (highest vs. lowest quintile: HR = 0.81, 95% CI = 0.72-0.92; Ptrend = 0.0001), at age 15 (HR = 0.79, 95% CI = 0.70-0.88; Ptrend ≤ 0.0001) and at age 30 (HR = 0.90, 95% CI = 0.82-0.99; Ptrend = 0.21) were associated with a decreased risk of endometriosis. LIMITATIONS, REASONS FOR CAUTION: Self-reported endometriosis diagnosis may be prone to misclassification; however, we restricted our definition to laparoscopically confirmed endometriosis, which has been shown to have high validity compared to medical records. WIDER IMPLICATIONS OF THE FINDINGS: Our results suggest that tanning bed use in early adulthood increases endometriosis risk, potentially through a harmful effect of ultraviolet A wavelengths, and that residential UV exposure reduces risk, possibly via optimal vitamin D synthesis. These findings should be investigated further to enhance our understanding of endometriosis aetiology. STUDY FUNDING/COMPETING INTEREST(S): This project was supported by NICHD grants HD48544 and HD52473, HD57210, NIH grant CA50385, CA176726. M.K. was supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme (#PIOF-GA-2011-302078) and is grateful to the Philippe Foundation and the Bettencourt-Schueller Foundation for their financial support. H.R.H. is supported by the National Cancer Institute, National Institutes of Health (K22 CA193860). The authors have nothing to disclose. TRIAL REGISTRATION NUMBER: N/A.

Perfluorinated alkylated substances serum concentration and breast cancer risk: Evidence from a nested case-control study in the French E3N cohort.

Endocrine-disrupting chemicals are proposed to increase breast cancer (BC) incidence. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), two perfluorinated alkylated substances (PFASs), are suspected to be ubiquitously present in the blood of human population worldwide. We investigated the associations between serum concentrations of these substances and BC risk. Etude Epidémiologique auprès de femmes de l'Education Nationale is a cohort of 98,995 French women born in 1925-1950 and followed up since 1990. We sampled 194 BC cases and 194 controls from women with available blood samples. Serum concentrations of PFASs were measured by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Adjusted conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). All statistical tests were two sided. While PFASs concentrations were not associated with BC risk overall, we found positively linear associations between PFOS concentrations and the risk of ER+ (3rd quartile: OR = 2.22 [CI = 1.05-4.69]; 4th quartile: OR = 2.33 [CI = 1.11-4.90]); Ptrend = 0.04) and PR+ tumors (3rd quartile: OR = 2.47 [CI = 1.07-5.65]; 4th quartile: OR = 2.76 [CI = 1.21-6.30]; Ptrend = 0.02). When considering receptor-negative tumors, only the 2nd quartile of PFOS was associated with risk (ER-: OR = 15.40 [CI = 1.84-129.19]; PR-: OR = 3.47 [CI = 1.29-9.15]). While there was no association between PFOA and receptor-positive BC risk, the 2nd quartile of PFOA was positively associated with the risk of receptor-negative tumors (ER-: OR = 7.73 [CI = 1.46-41.08]; PR-: OR = 3.44 [CI = 1.30-9.10]). PFAS circulating levels were differentially associated with BC risk. While PFOS concentration was linearly associated with receptor-positive tumors, only low concentrations of PFOS and PFOA were associated with receptor-negative tumors. Our findings highlight the importance of considering exposure to PFASs as a potential risk factor for BC.

Serologic markers of Chlamydia trachomatis and other sexually transmitted infections and subsequent ovarian cancer risk: Results from the EPIC cohort.

A substantial proportion of epithelial ovarian cancer (EOC) arises in the fallopian tube and other epithelia of the upper genital tract; these epithelia may incur damage and neoplastic transformation after sexually transmitted infections (STI) and pelvic inflammatory disease. We investigated the hypothesis that past STI infection, particularly Chlamydia trachomatis, is associated with higher EOC risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort including 791 cases and 1669 matched controls. Serum antibodies against C. trachomatis, Mycoplasma genitalium, herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) 16, 18 and 45 were assessed using multiplex fluorescent bead-based serology. Conditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) comparing women with positive vs. negative serology. A total of 40% of the study population was seropositive to at least one STI. Positive serology to C. trachomatis Pgp3 antibodies was not associated with EOC risk overall, but with higher risk of the mucinous histotype (RR = 2.30 [95% CI = 1.22-4.32]). Positive serology for chlamydia heat shock protein 60 (cHSP60-1) was associated with higher risk of EOC overall (1.36 [1.13-1.64]) and with the serous subtype (1.44 [1.12-1.85]). None of the other evaluated STIs were associated with EOC risk overall; however, HSV-2 was associated with higher risk of endometrioid EOC (2.35 [1.24-4.43]). The findings of our study suggest a potential role of C. trachomatis in the carcinogenesis of serous and mucinous EOC, while HSV-2 might promote the development of endometrioid disease.

Theoretical potential for endometrial cancer prevention through primary risk factor modification: Estimates from the EPIC cohort.

Endometrial cancer (EC) incidence rates vary ~10-fold worldwide, in part due to variation in EC risk factor profiles. Using an EC risk model previously developed in the European EPIC cohort, we evaluated the prevention potential of modified EC risk factor patterns and whether differences in EC incidence between a European population and low-risk countries can be explained by differences in these patterns. Predicted EC incidence rates were estimated over 10 years of follow-up for the cohort before and after modifying risk factor profiles. Risk factors considered were: body mass index (BMI, kg/m2 ), use of postmenopausal hormone therapy (HT) and oral contraceptives (OC) (potentially modifiable); and, parity, ages at first birth, menarche and menopause (environmentally conditioned, but not readily modifiable). Modeled alterations in BMI (to all ≤23 kg/m2 ) and HT use (to all non-HT users) profiles resulted in a 30% reduction in predicted EC incidence rates; individually, longer duration of OC use (to all ≥10 years) resulted in a 42.5% reduction. Modeled changes in not readily modifiable exposures (i.e., those not contributing to prevention potential) resulted in ≤24.6% reduction in predicted EC incidence. Women in the lowest decile of a risk score based on the evaluated exposures had risk similar to a low risk countries; however, this was driven by relatively long use of OCs (median = 23 years). Our findings support avoidance of overweight BMI and of HT use as prevention strategies for EC in a European population; OC use must be considered in the context of benefits and risks.

Exogenous hormone use and cutaneous melanoma risk in women: The European Prospective Investigation into Cancer and Nutrition.

Evidence suggests an influence of sex hormones on cutaneous melanoma risk, but epidemiologic findings are conflicting. We examined the associations between use of oral contraceptives (OCs) and menopausal hormone therapy (MHT) and melanoma risk in women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is a prospective cohort study initiated in 1992 in 10 European countries. Information on exogenous hormone use at baseline was derived from country-specific self-administered questionnaires. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Over 1992-2015, 1,696 melanoma cases were identified among 334,483 women, whereof 770 cases among 134,758 postmenopausal women. There was a positive, borderline-significant association between OC use and melanoma risk (HR = 1.12, 95% CI = 1.00-1.26), with no detected heterogeneity across countries (phomogeneity = 0.42). This risk increased linearly with duration of use (ptrend = 0.01). Among postmenopausal women, ever use of MHT was associated with a nonsignificant increase in melanoma risk overall (HR = 1.14, 95% CI = 0.97-1.43), which was heterogeneous across countries (phomogeneity = 0.05). Our findings do not support a strong and direct association between exogenous hormone use and melanoma risk. In order to better understand these relations, further research should be performed using prospectively collected data including detailed information on types of hormone, and on sun exposure, which may act as an important confounder or effect modifier on these relations.

Mediation analysis of the alcohol-postmenopausal breast cancer relationship by sex hormones in the EPIC cohort.

Alcohol consumption is associated with higher risk of breast cancer (BC); however, the biological mechanisms underlying this association are not fully elucidated, particularly the extent to which this relationship is mediated by sex hormone levels. Circulating concentrations of estradiol, testosterone, their free fractions and sex-hormone binding globulin (SHBG), were examined in 430 incident BC cases and 645 matched controls among alcohol-consuming postmenopausal women nested within the European Prospective Investigation into Cancer and Nutrition. Mediation analysis was applied to assess whether individual hormone levels mediated the relationship between alcohol intake and BC risk. An alcohol-related hormonal signature, obtained by partial least square (PLS) regression, was evaluated as a potential mediator. Total (TE), natural direct and natural indirect effects (NIE) were estimated. Alcohol intake was positively associated with overall BC risk and specifically with estrogen receptor-positive tumors with respectively TE = 1.17(95%CI: 1.01,1.35) and 1.36(1.08,1.70) for a 1-standard deviation (1-SD) increase of intake. There was no evidence of mediation by sex steroids or SHBG separately except for a weak indirect effect through free estradiol where NIE = 1.03(1.00,1.06). However, an alcohol-related hormonal signature negatively associated with SHBG and positively with estradiol and testosterone was associated with BC risk (odds ratio [OR] = 1.25 [1.07,1.47]) for a 1-SD higher PLS score, and had a statistically significant NIE accounting for a mediated proportion of 24%. There was limited evidence of mediation of the alcohol-BC association by individual sex hormones. However, a hormonal signature, reflecting lower levels of SHBG and higher levels of sex steroids, mediated a substantial proportion of the association.

Premenopausal Use of Progestogens and Cutaneous Melanoma Risk: A French Prospective Cohort Study.

We investigated the influence of premenopausal use of progestogens on melanoma using data from E3N (Etude Epidémiologique Auprès de Femmes de l'Education Nationale), a prospective cohort of 98,995 French women, aged 40-65 years at inclusion. We used Cox models to adjust for age and melanoma risk factors. Over 1992-2008, 540 melanoma cases were ascertained among 79,558 women. We found a modest association between self-reported progestogen use and melanoma risk (hazard ratio (HR) = 1.23, 95% confidence interval (CI) = 1.02, 1.47), which was reduced after adjustment for melanoma risk factors (HR = 1.15, 95% CI: 0.95, 1.39). There was no heterogeneity across types of progestogens (P = 0.22), and use of multiple progestogens was positively associated with melanoma risk (HR = 1.33, 95% CI: 1.04, 1.70). Among users, we found no relationship with duration of progestogen use, age at start and last use, and time since first and last use. Although our results did not show evidence of a confounding effect of sun exposure, progestogen users had lower levels of residential sun exposure and were more likely to report sunscreen use, suggesting specific sun exposure profiles in users. Our findings do not support a strong influence of progestogens on melanoma risk. Further research is needed to confirm these results.

Lifestyle factors and risk of multimorbidity of cancer and cardiometabolic diseases: a multinational cohort study.

BACKGROUND: Although lifestyle factors have been studied in relation to individual non-communicable diseases (NCDs), their association with development of a subsequent NCD, defined as multimorbidity, has been scarcely investigated. The aim of this study was to investigate associations between five lifestyle factors and incident multimorbidity of cancer and cardiometabolic diseases. METHODS: In this prospective cohort study, 291,778 participants (64% women) from seven European countries, mostly aged 43 to 58 years and free of cancer, cardiovascular disease (CVD), and type 2 diabetes (T2D) at recruitment, were included. Incident multimorbidity of cancer and cardiometabolic diseases was defined as developing subsequently two diseases including first cancer at any site, CVD, and T2D in an individual. Multi-state modelling based on Cox regression was used to compute hazard ratios (HR) and 95% confidence intervals (95% CI) of developing cancer, CVD, or T2D, and subsequent transitions to multimorbidity, in relation to body mass index (BMI), smoking status, alcohol intake, physical activity, adherence to the Mediterranean diet, and their combination as a healthy lifestyle index (HLI) score. Cumulative incidence functions (CIFs) were estimated to compute 10-year absolute risks for transitions from healthy to cancer at any site, CVD (both fatal and non-fatal), or T2D, and to subsequent multimorbidity after each of the three NCDs. RESULTS: During a median follow-up of 11 years, 1910 men and 1334 women developed multimorbidity of cancer and cardiometabolic diseases. A higher HLI, reflecting healthy lifestyles, was strongly inversely associated with multimorbidity, with hazard ratios per 3-unit increment of 0.75 (95% CI, 0.71 to 0.81), 0.84 (0.79 to 0.90), and 0.82 (0.77 to 0.88) after cancer, CVD, and T2D, respectively. After T2D, the 10-year absolute risks of multimorbidity were 40% and 25% for men and women, respectively, with unhealthy lifestyle, and 30% and 18% for men and women with healthy lifestyles. CONCLUSION: Pre-diagnostic healthy lifestyle behaviours were strongly inversely associated with the risk of cancer and cardiometabolic diseases, and with the prognosis of these diseases by reducing risk of multimorbidity.

Citrus intake and risk of skin cancer in the European Prospective Investigation into Cancer and Nutrition cohort (EPIC).

Citrus intake has been suggested to increase the risk of skin cancer. Although this relation is highly plausible biologically, epidemiologic evidence is lacking. We aimed to examine the potential association between citrus intake and skin cancer risk. EPIC is an ongoing multi-center prospective cohort initiated in 1992 and involving ~ 520,000 participants who have been followed-up in 23 centers from 10 European countries. Dietary data were collected at baseline using validated country-specific dietary questionnaires. We used Cox proportional hazards regression models to compute hazard ratios (HR) and 95% confidence intervals (CI). During a mean follow-up of 13.7 years, 8448 skin cancer cases were identified among 270,112 participants. We observed a positive linear dose-response relationship between total citrus intake and skin cancer risk (HR = 1.10, 95% CI 1.03-1.18 in the highest vs. lowest quartile; Ptrend = 0.001), particularly with basal cell carcinoma (BCC) (HR = 1.11, 95% CI 1.02-1.20, Ptrend = 0.007) and squamous cell carcinoma (SCC) (HR = 1.23, 95% CI 1.04-1.47, Ptrend = 0.01). Citrus fruit intake was positively associated with skin cancer risk (HR = 1.08, 95% CI 1.01-1.16, Ptrend = 0.01), particularly with melanoma (HR = 1.23, 95% CI 1.02-1.48; Ptrend = 0.01), although with no heterogeneity across skin cancer types (Phomogeneity = 0.21). Citrus juice was positively associated with skin cancer risk (Ptrend = 0.004), particularly with BCC (Ptrend = 0.008) and SCC (Ptrend = 0.004), but not with melanoma (Phomogeneity = 0.02). Our study suggests moderate positive linear dose-response relationships between citrus intake and skin cancer risk. Studies with available biomarker data and the ability to examine sun exposure behaviors are warranted to clarify these associations and examine the phototoxicity mechanisms of furocoumarin-rich foods.

Plasma concentration of brominated flame retardants and postmenopausal breast cancer risk: a nested case-control study in the French E3N cohort.

BACKGROUND: Brominated flame retardants (BFRs) are lipophilic substances with endocrine-disrupting properties. To date, only few investigations, mainly retrospective case-control studies, have explored the link between internal levels of BFRs and the risk of breast cancer, leading to conflicting results. We investigated the associations between plasma concentrations of two main groups of BFRs, PBDEs (pentabromodiphenyl ethers) and PBBs (polybrominated biphenyls), and the risk of breast cancer in a nested case-control study. METHODS: A total of 197 incident breast cancer cases and 197 controls with a blood sample collected in 1994-1999 were included. Plasma levels of PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE153, BDE-154) and of PBB-153 were measured by gas chromatography coupled to high-resolution mass spectrometry. Conditional logistic regression models, adjusted for potential confounders, were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Women were aged 56 years on average at blood draw. All cases, except for one, were diagnosed after menopause, with an average age at diagnosis of 68 years. Overall, we found no evidence of an association between plasma levels of PBDEs and PBB-153 and postmenopausal breast cancer risk (log-concentrations of BFRs yielding non-statistically significant ORs of 0.87 to 1.07). The analysis showed a non-linear inverse association for BDE-100 and BDE-153 and postmenopausal breast cancer risk; nevertheless, these findings were statistically significant only when the exposure was modeled as ng/L plasma (third vs. first quintile: OR = 0.42, 95%CI = 0.19-0.93 and OR = 0.42, 95%CI = 0.18-0.98, respectively) and not when modeled as ng/gr of lipids (OR = 0.58, 95%CI = 0.27-1.25 and OR = 0.53, 95%CI = 0.25-1.17). These results were unchanged in stratified analyses by tumor hormone receptor expression or body mass index. CONCLUSIONS: Our results suggest no clear association between internal levels of PBDEs and PBB-153 and the risk of breast cancer in postmenopausal women. However, these findings need to be carefully interpreted, taking into account limitations due to the limited number of women included in the study, the lack of information concerning genetic susceptibility of cases, and the unavailability of exposure assessment during critical windows of susceptibility for breast cancer. More studies are warranted to further investigate the relationships between PBDE and PBB exposure and breast cancer risk.

Circulating insulin-like growth factor I in relation to melanoma risk in the European prospective investigation into cancer and nutrition.

Insulin-like growth factor-I (IGF-I) regulates cell proliferation and apoptosis, and is thought to play a role in tumour development. Previous prospective studies have shown that higher circulating concentrations of IGF-I are associated with a higher risk of cancers at specific sites, including breast and prostate. No prospective study has examined the association between circulating IGF-I concentrations and melanoma risk. A nested case-control study of 1,221 melanoma cases and 1,221 controls was performed in the European Prospective Investigation into Cancer and Nutrition cohort, a prospective cohort of 520,000 participants recruited from 10 European countries. Conditional logistic regression was used to estimate odds ratios (ORs) for incident melanoma in relation to circulating IGF-I concentrations, measured by immunoassay. Analyses were conditioned on the matching factors and further adjusted for age at blood collection, education, height, BMI, smoking status, alcohol intake, marital status, physical activity and in women only, use of menopausal hormone therapy. There was no significant association between circulating IGF-I concentration and melanoma risk (OR for highest vs lowest fifth = 0.93 [95% confidence interval [CI]: 0.71 to 1.22]). There was no significant heterogeneity in the association between IGF-I concentrations and melanoma risk when subdivided by gender, age at blood collection, BMI, height, age at diagnosis, time between blood collection and diagnosis, or by anatomical site or histological subtype of the tumour (Pheterogeneity≥0.078). We found no evidence for an association between circulating concentrations of IGF-I measured in adulthood and the risk of melanoma.