Family structure and living arrangements as indicators of social isolation, and prostate cancer risk

Abstract

Social isolation has been linked to a poorer prostate cancer prognosis. Little is known about how it could also influence its incidence. We investigated the association between family structure and living arrangements as potential indicators of social isolation, and prostate cancer risk, globally and according to disease aggressiveness.Data from the Prostate Cancer & Environment Study (PROtEuS), a case-control population-based study conducted between 2005 and 2012 in Montreal, Canada, were used. The study population comprised 1931 incident cases of prostate cancer, aged ≤75 years, and 1994 age-matched (±5 years) population controls. In-person interviews collected information on family composition and living arrangements recently and at age 40. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for potential confounders.Single men had an increased risk of high-grade prostate cancer at diagnosis (OR 1.80; 95% CI 1.29–2.51), compared to men currently married or with a partner. Having at least one daughter was associated with a lower risk of aggressive cancer (OR 0.76; 95% CI 0.61–0.96) while no association was found with having son(s). An inverse dose-response relationship was observed between the number of people living with the subject 2 years before diagnosis/interview and prostate cancer risk (p-trend<0.001).These results suggest a protective role of a rich personal environment on the risk of developing prostate cancer. As several of the associations studied here are novel, replication is required.