Prognosis and conditional survival among women with newly diagnosed ovarian cancer

An important question in determining long-term prognosis for women with ovarian cancer is whether risk of death changes the longer a woman lives. Large real-world datasets permit assessment of conditional survival (CS) given both prior overall survival (OS) and real-world progression-free survival (rwPFS). Using a longitudinal dataset from US oncology centers, this study included 6778 women with ovarian cancer. We calculated CS rates as the Kaplan-Meier probability of surviving an additional 1 or 5 years, given no mortality (OS) or disease progression (rwPFS) event in the previous 0.5–5 years since first-line chemotherapy initiation, adjusted for factors associated with OS based on multivariable Cox regression. Median study follow-up was 9 years (range, 1–44) from first-line initiation to data cutoff (17-Feb-2021). Median OS was 58.0 months (95% CI, 54.9–60.8); median rwPFS was 18.4 months (17.4–19.4). The adjusted 1-year CS rate (ie, rate of 1 year additional survival) did not vary based on time alive, whereas the adjusted 5-year CS rate increased from 48.5% (47.0%–50.1%) for women who had already survived 6 months to 66.4% (63.3%–69.6%) for those already surviving 5 years (thus surviving 10 years total). The adjusted 1-year CS rate increased from 90.4% (89.5%–91.4%) with no rwPFS event at 6 months to 97.6% (96.4%–98.8%) with no rwPFS event at 5 years; adjusted 5-year CS rate increased from 53.7% (52.0%–55.5%) to 85.0% (81.2%–88.9%), respectively. This analysis extends the concept of CS by also conditioning on time progression-free. Patients with longer rwPFS experience longer survival than patients with shorter rwPFS. •Women with ovarian cancer have an increasing probability of survival with increasing time survived after the diagnosis.•Conditional survival (CS) is the probability of surviving +y years, given already having survived x years post-diagnosis.•The 5-year CS rate increased from 54% for survival with no disease progression at 6 mos to 85% with no progression at 5 yrs.•The prognosis for ovarian cancer improved substantially with time for women alive without disease progression.