Barnard ME, Beeghly-Fadiel A, Milne GL, et al. - Via this case–control study nested in the Nurses’ Health Study (NHS), NHSII, and Shanghai Women's Health Study, researchers assessed if there exists a link between higher prediagnosis PGE-M [a urinary biomarker of prostaglandin E2] and increased ovarian cancer risk in these 3 prospective cohorts. They analyzed overall 304 cases of epithelial ovarian cancer and 600 matched controls. They measured urinary PGE-M using LC/MS with normalization to creatinine. They used conditional logistic regression, with PGE-M levels modeled in quartiles, to estimate ORs and 95% confidence intervals. Multivariable models adjusted for ovarian cancer risk factors were used. Findings revealed no significant link between prediagnosis urinary PGE-M levels and ovarian cancer risk.