Abstract
Women with ovarian cancer may be at increased risk of severe COVID-19 outcomes. This study aimed to compare mortality and clinical outcomes between women with severe COVID-19, with and without a history of ovarian cancer. We conducted a matched case-control study using national surveillance data. Cases included women with severe COVID-19 and a history of ovarian cancer; controls were women with severe COVID-19 without such history. Matching was done at a 1:4 ratio using age, comorbidities, vaccination status, diagnosis date, and region. The primary outcome was COVID-19-related mortality. A total of 474 ovarian cancer cases and 1,896 controls were included. Mortality was significantly higher in women with ovarian cancer (54.9 vs 32.7%, P<0.001). Multivariate analysis showed that ovarian cancer increased the risk of death (OR: 2.76, 95%CI: 2.22-3.43). Age also influenced mortality: OR 2.57 (95%CI: 2.11-3.13) for women aged 65-84, and OR 3.86 (95%CI: 2.52-5.97) for those 85 and older. Vaccination provided protection: complete vaccination (OR: 0.67, 95%CI: 0.51-0.88) and complete vaccination plus booster (OR: 0.35, 95%CI: 0.27-0.47). Women with ovarian cancer had a significantly higher risk of death from severe COVID-19. Vaccination, particularly with a booster, was associated with 65% reduced mortality.