MSH2 and Lynch syndrome: Ovarian cancer is much less common than endometrial cancer in Lynch syndrome (0.5% vs 5.8%), consistent with the Prospective Lynch Syndrome Database (3–17%).3 Based on these rates, 12–70 ovarian cancers would be expected to occur by 70 years in 413 women depending on pathogenic variant, with an estimated number needed to treat of 6–34.3 Six surgeries would need to occur in MSH2 carriers to detect one ovarian cancer, compared with 34 surgeries needed in PMS2 carriers.