Marianne Levesque

Background: Identifying people with Lynch syndrome, a genetic condition predisposing those affected to colorectal, endometrial and other cancers, allows for implementation of risk-reducing strategies for patients and their families. The goal of this study was to describe screening and testing practices for this condition among people with endometrial cancer in Nova Scotia, Canada, and to determine the prevalence of Lynch syndrome in this population. Methods: All patients diagnosed with endometrial cancer in Nova Scotia between May 1, 2017, and Apr. 30, 2020 were identified through a provincial gynecologic oncology database. Patients from out of province were excluded. We collected age, body mass index, tumour mismatch repair protein immunohistochemistry results, personal and family histories, and germline testing information for all patients. Results: We identified 465 people diagosed with endometrial cancer during the study period. Most were aged 51 years or older, and had obesity and low-grade early-stage endometrioid tumours. Tumour immunohistochemistry testing was performed in 444 cases (95.5%). Based on local criteria, 189 patients were eligible for genetic counselling, of whom 156 (82.5%) were referred to medical genetics. Of the 98 patients who underwent germline testing, 9 (9.2%) were diagnosed with Lynch syndrome. Interpretation: The prevalence of Lynch syndrome was at least 1.9% (9/465) in this population. Our results illustrate successful implementation of universal tumour testing; however, there remains a gap in access to genetic counselling.

Persistent organic pollutants (POPs) are toxic chemicals with demonstrable effects on pregnancy and neonatal outcomes. The associations of early pregnancy body mass index (BMI) and antenatal weight changes with circulating POP concentrations are poorly understood in the Canadian context. The aim of this study was to explore the relationship between maternal BMI in the first trimester, weight change from pre-pregnancy to 6–13 weeks of pregnancy, and first-trimester plasma POP concentrations among Canadian pregnant women. We analyzed data collected as part of the Maternal-Infant Research on Environmental Chemicals (MIREC) study and evaluated POP concentrations based on first-trimester BMI and early gestational weight change categories. We tested for overall differences using Kruskal-Wallis tests. The associations between first-trimester maternal BMI, weight change, and plasma concentrations of 41 POPs were evaluated using censored regression models. After controlling for potential confounders, first-trimester plasma levels of multiple POPs differed significantly across BMI categories, with the highest concentrations in underweight/normal-weight individuals and the lowest in class III obese individuals. Our findings provide preliminary evidence of higher circulating POP levels in individuals with obesity and align with previous findings of an inverse relationship between circulating POP concentrations and BMI in pregnancy. Future studies should prospectively evaluate the interplay between weight change and POP concentrations throughout pregnancy to inform gestational weight gain recommendations for pregnant individuals with obesity.