IntroductionOvarian cancer (OC) is the eighth most common cancer in women, with a poor prognosis, particularly in older women. The aim of this study was to describe an octogenarian population with OC and to examine the differences in net survival (NS) according to age. Material and methodsIn this retrospective observational population-based study from a gynecological cancer registry, patients aged > 18 years with an identified epithelial ovarian cancer stage IA to IVB diagnosed between 1998 and 2018 were included. Patients with non-available FIGO stage were excluded. Patients were stratified into three age groups: <70, 70-79 and ≥80 years, then by OC stage (FIGO I-II, IIIA-IIIB, IIIC-IV). Sociodemographic and cancer-related variables were compared using univariate test (Khi²). The 5-year NS was calculated using the Pohar-Perme method. ResultsAmong the 721 patients included: 462 (64.1%) were younger than 70 years, 176 (24.4%) were aged between 70 and 79 years, and 83 (11.85%) were aged 80 years or older. Patients ≥80 years had a trend for lower rate of serous carcinoma than the other age subgroups. As age increased, patients were less likely to undergo surgery and chemotherapy. While 73% of women <70 years received a combination of surgery and chemotherapy, the rate was 62% among women 70-79 years and 27% among women ≥80 years (p<.0001). When focusing on FIGO IIIC-IV stages, the 5-year NS rate for women <70 years was 45.1% (95% CI 39.1-52.0). For women 70-79 years, it was 25.9% (95% CI 18.6-36.1), and for those ≥80 years, it was 19.5% (95% CI 10.0-38.0) (p<.005). DiscussionThe oldest patients had less optimal treatment and a lower NS compared to patients in their seventies or younger. Frailty should be carefully assessed to optimize care in the oldest patients with OC.