Joint Effect of Genotypic and Phenotypic Features of Reproductive Factors on Endometrial Cancer Risk

Early Pregnancy Plasma Per- and Polyfluoroalkyl Substances (PFAS) and Maternal Midlife Adiposity

CONTEXT

Evidence suggests that exposure to per- and polyfluoroalkyl substances (PFAS) increases the risk of developing cardiometabolic disease risk factors. Limited research has evaluated associations between PFAS, assessed during pregnancy, a sensitive window for maternal endocrine effects, and long-term maternal adiposity.

OBJECTIVE

Estimate associations of early pregnancy measures of individual PFAS, and PFAS mixtures, with maternal adiposity in midlife.

METHODS

We studied 547 Project Viva participants with measures of early pregnancy (mean gestation 10.0 weeks; mean age 32.5 years) plasma concentrations of 6 PFAS and midlife adiposity outcomes (mean follow-up 17.7 years; mean age 50.7 years), including weight, waist circumference (WC), trunk fat mass (TFM), and total body fat mass (TBFM). We used linear regression and Bayesian Kernel Machine Regression (BKMR).

RESULTS

Linear regression estimated higher midlife weight per doubling of perfluorooctane sulfonate (PFOS) (3.8 kg [95% CI: 1.6, 5.9]) and 2-(N-ethyl-perfluorooctane sulfonamido) acetate (2.3 kg [95% CI: 0.9, 3.7]). BKMR analyses of single PFAS plasma concentrations (comparing the 25th percentile concentration to the 75th percentile) showed a positive association between PFOS and midlife adiposity (weight: 7.7 kg [95% CI: 4.0, 11.5]; TFM: 1.2 kg [95% CI: 0.0, 2.3]; TBFM: 3.0 kg [95% CI: 0.8, 5.2]), but inverse associations with perfluorononanoate (weight: -6.0 kg [95% CI: -8.5, -3.5]; WC: -1.8 cm [95% CI: -3.2, -0.3]; TFM: -0.8 kg [95% CI: -1.5, -0.1]; TBFM: -1.4 kg [95% CI: -2.7, -0.3]) and perfluorohexane sulfonate (TFM: -0.8 kg [95% CI: -1.5, -0.1]; TBFM: -1.4 kg [95% CI: -2.6, -0.2]). No associations were observed with the overall PFAS mixture.

CONCLUSION

Select PFAS, assessed in pregnancy, may differentially affect maternal midlife adiposity, influencing later-life maternal cardiometabolic health.

Number of lifetime menses increases breast cancer occurrence in postmenopausal women at high familial risk

It is increasingly thought that part of human susceptibility to cancer is the result of evolutionary mismatches: our ancestors evolved cancer suppression mechanisms in a world largely different from our modern environments. In that context, it has been shown in cohorts from general Western populations that reproductive traits modulate breast cancer risk. Overall, the more menses women experience, the more at risk they are to develop postmenopausal breast cancer. This points towards an evolutionary mismatch but brings the question whether the reproductive pattern also modulates the breast cancer risk in menopausal women at high familial risk. We thus studied the influence of menses on breast cancer risk in a case–control study of 90 postmenopausal women (including BRCA1/2 and non BRCA1/2) nested within a cohort at high familial risk. We tested the association of the lifetime number of menses and the number of menses before first full-term pregnancy with postmenopausal breast cancer risk using Cox survival models. We showed that the total lifetime number of menses was significantly associated with postmenopausal breast cancer risk and associated with a quicker onset of breast cancer after menopause. Those results align with similar studies lead in general cohorts and suggest that the reproductive pattern modulates the familial risk of developing breast cancer after menopause. Altogether, those results impact how we envision breast cancer prevention and call for more research on how ecological and genetic factors shape breast cancer risk.

Association of the Age at Menarche with Site-Specific Cancer Risks in Pooled Data from Nine Cohorts

The average age at menarche declined in European and U.S. populations during the 19th and 20th centuries. The timing of pubertal events may have broad implications for chronic disease risks in aging women. Here we tested for associations of recalled menarcheal age with risks of 19 cancers in 536,450 women [median age, 60 years (range, 31-39 years)] in nine prospective U.S. and European cohorts that enrolled participants from 1981 to 1998. Cox regression estimated multivariable-adjusted HRs and 95% confidence intervals (CI) for associations of the age at menarche with risk of each cancer in each cohort and random-effects meta-analysis was used to generate summary estimates for each cancer. Over a median 10 years of follow-up, 60,968 women were diagnosed with a first primary incident cancer. Inverse linear associations were observed for seven of 19 cancers studied. Each additional year in the age at menarche was associated with reduced risks of endometrial cancer (HR = 0.91; 95% CI, 0.89-0.94), liver cancer (HR = 0.92; 95% CI, 0.85-0.99), melanoma (HR = 0.95; 95% CI, 0.93-0.98), bladder cancer (HR = 0.96; 95% CI, 0.93-0.99), and cancers of the colon (HR = 0.97; 95% CI, 0.96-0.99), lung (HR = 0.98; 95% CI, 0.96-0.99), and breast (HR = 0.98; 95% CI, 0.93-0.99). All but one of these associations remained statistically significant following adjustment for baseline body mass index. Similarities in the observed associations between menarche and seven cancers suggest shared underlying causes rooted early in life. We propose as a testable hypothesis that early exposure to sex hormones increases mid-life cancer risks by altering functional capacities of stem cells with roles in systemic energy balance and tissue homeostasis. SIGNIFICANCE: Age at menarche is associated with risk for seven cancers in middle-aged women, and understanding the shared underlying causal pathways across these cancers may suggest new avenues for cancer prevention.

Promotion of the occurrence of endometrioid carcinoma by S100 calcium binding protein P

Background

Endometrial cancer, one of the most common malignant tumors, is a serious threat to women’s health. Endometrial hyperplasia is a precursor of endometrial cancer. S100 calcium binding protein P (S100P) has been found to play important roles in many types of cancer. The present study aimed to investigate the expression of S100P in endometrial cancer and its precursor lesions, and to explore the possible mechanisms.

Methods

We collected paraffin sections of normal endometrium, simple and complex non-atypical hyperplasia, atypical hyperplasia, and endometrioid carcinoma. The expression of S100P in endometrial cancer and its precancerous lesions was observed using immunohistochemistry. We also cultured primary endometrial cells and endometrial cancer cell lines (Ishikawa and RL95–2), and observed the expression of S100P in these cells. Laser confocal microscopy was used to observe the co-localization of S100P and its interacting protein Ezrin in RL95–2 cells. We employed lentiviruses to knockdown and overexpress S100P and then detected the F-actin distribution and cell invasion using phalloidin staining and Transwell assays.

Results

There was a gradual increase in the S100P signal as the disease progressed from normal endometrium and simple non-atypical hyperplasia, to complex non-atypical hyperplasia, atypical hyperplasia, and then to endometrial cancer. S100P was mainly distributed in the cytoplasm and co-localized with Ezrin in endometrial cancer cells. After knocking down S100P, F-actin aggregated in the nucleus or to the local cell membrane. Furthermore, knockdown of S100P in Ishikawa cells decreased their cell invasion capability. Meanwhile, S100P overexpression in endometrial stromal cells increased cell invasion.

Conclusions

These data suggested that S100P might be involved in the occurrence and development of endometrial cancer via interaction with Ezrin and re-organization of F-actin to promote cell invasion.

ROR1 is upregulated in endometrial cancer and represents a novel therapeutic target

ROR1 and ROR2 are receptor tyrosine kinases with altered expression in a range of cancers. Silencing ROR1 or ROR2 in different tumour types has been shown to inhibit proliferation and decrease metastatic potential. The aim of this study was to investigate the role of ROR1 and ROR2 in endometrial cancer via immunohistochemistry (IHC) in a large endometrial cancer patient cohort (n = 499) and through in vitro analysis in endometrial cancer cell lines. Correlation was assessed between ROR1/2 expression and clinicopathological parameters. Kaplan Meier curves were produced for 5-year progression free survival (PFS) and overall survival (OS) with low/moderate versus high ROR1/2 intensity. Cox multivariate regression was applied to analyse the effect of selected covariates on the PFS and OS. The effect of ROR1 and/or ROR2 modulation on cell proliferation, adhesion, migration and invasion was analysed in two endometrial cancer cell lines (KLE and MFE-296). We observed a significant decrease in OS and PFS in patients with high ROR1 expression. ROR1 silencing and ROR2 overexpression significantly inhibited proliferation of KLE endometrial cancer cells and decreased migration. This study supports the oncogenic role of ROR1 in endometrial cancer, and warrants investigation of future application of ROR1-targeting therapies in endometrial cancer patients.

Lifetime number of years of menstruation as a risk index for postmenopausal endometrial cancer in the Norwegian Women and Cancer Study

INTRODUCTION

Lifetime number of years of menstruation (LNYM) reflects a woman's cumulative exposure to endogenous estrogen and can be used as a measure of the combined effect of reproductive factors related to endometrial cancer (EC) risk.

MATERIAL AND METHODS

We aimed to study the association between LNYM and EC risk among postmenopausal women and calculate the population attributable fraction of EC for different LNYM categories. Our study sample consisted of 117 589 women from the Norwegian Women and Cancer (NOWAC) Study. All women were aged 30-70 years at enrollment and completed a baseline questionnaire between 1991 and 2006. Women were followed up for EC to December 2014 through linkages to national registries. We used Cox proportional hazards models to estimate hazard ratios with 95% confidence intervals (95% CIs), adjusted for potential confounders.

RESULTS

In all, 720 women developed EC. We found a statistically significant, positive dose-response relationship between LNYM and EC, with a 9.1% higher risk for each additional year of LNYM (P for trend < .001). Using the LNYM category ≥40 as a reference, the hazard ratios for LNYM <25, 25-29, 30-34, 35-39 were 0.17 (95% CI 0.22-0.27), 0.25 (95% CI 0.17-0.36), 0.43 (95% CI 0.32-0.58), and 0.68 (95% CI 0.51-0.92), respectively. The association between LNYM and EC was independent of incomplete pregnancies, menopausal hormone therapy, diabetes, and body mass index. When considering the population attributable fraction, 67% of EC was estimated to be attributable to LNYM ≥25 years.

CONCLUSIONS

Our study supports that increasing LNYM is an important and independent predictor of EC risk.

Meta-dimensional data integration identifies critical pathways for susceptibility, tumorigenesis and progression of endometrial cancer

Endometrial Cancer (EC) is one of the most common female cancers. Genome-wide association studies (GWAS) have been investigated to identify genetic polymorphisms that are predictive of EC risks. Here we utilized a meta-dimensional integrative approach to seek genetically susceptible pathways that may be associated with tumorigenesis and progression of EC. We analyzed GWAS data obtained from Connecticut Endometrial Cancer Study (CECS) and identified the top 20 EC susceptible pathways. To further verify the significance of top 20 EC susceptible pathways, we conducted pathway-level multi-omics analyses using EC exome-Seq, RNA-Seq and survival data, all based on The Cancer Genome Atlas (TCGA) samples. We measured the overall consistent rankings of these pathways in all four data types. Some well-studied pathways, such as p53 signaling and cell cycle pathways, show consistently high rankings across different analyses. Additionally, other cell signaling pathways (e.g. IGF-1/mTOR, rac-1 and IL-5 pathway), genetic information processing pathway (e.g. homologous recombination) and metabolism pathway (e.g. sphingolipid metabolism) are also highly associated with EC risks, diagnosis and prognosis. In conclusion, the meta-dimensional integration of EC cohorts has suggested some common pathways that may be associated from predisposition, tumorigenesis to progression.