Ten-year conditional probability of survival for patients with ovarian cancer: A new metric tailored to Long-term survivors.

OBJECTIVES: We assessed a conditional probability of survival (CPS) model to determine the probability of living 10 years after ovarian cancer diagnosis after having already survived 5 years. METHODS: We identified patients newly diagnosed with high-grade epithelial ovarian cancer from 1/1/2001-12/31/2009 and treated at our institution. Patients with <3 years follow-up were excluded. CPS was defined as the probability of surviving additional years (y) based on the condition a patient had already survived a given time (x): S(x + y)/S(x). Confidence intervals were estimated using a variation of Greenwood's formula. RESULTS: Of 916 patients meeting inclusion criteria, 473 (52%) were diagnosed from 2001 to 2005 and 443 (48%) from 2006 to 2009. Median age at diagnosis was 60 years (range, 25-95). The conventional 10-year OS rate for all patients was 29% (95% CI: 26%-32%)-75% (95% CI: 68%-82%) for stage I/II disease, 22% (95% CI: 19%-26%) for stage III, and 6.9% (95% CI: 3.9%-12%) for stage IV. For patients <65 years, the 10-year CPS for 5-year survivors was 65% (95% CI: 59%-70%); for those ≥65 years, it was 48% (95% CI: 38%-57%). For patients <65 years, the 10-year CPS for 5-year survivors by stage was: stage I/II, 89% (95% CI: 81%-94%); stage III, 58% (95% CI: 50%-66%); and stage IV, 26% (95% CI: 12%-42%). For patients ≥65 years, rates by stage were 78% (95% CI: 53%-91%), 42% (95% CI: 30%-53%), and 29% (95% CI: 7%-56%), respectively. CONCLUSIONS: For long-term survivors with high-grade epithelial ovarian cancer, CPS provides better prediction of survival than conventional methods.

Conditional Probability of Survival and Prognostic Factors in Long-Term Survivors of High-Grade Serous Ovarian Cancer.

Objective: High-grade serous ovarian cancers (HGSOC) are heterogeneous, often diagnosed at an advanced stage, and associated with poor overall survival (OS, 39% at five years). There are few data about the prognostic factors of late relapses in HGSOC patients who survived ≥five years, long-term survivors (LTS). The aim of our study is to assess the probability of survival according to the already survived time from diagnosis. Methods: Data from HGSOC patients treated between 1995 and 2016 were retrospectively collected to estimate the conditional probability of survival (CPS), probability of surviving Y years after diagnosis when the patient had already survived X years, and to determine the LTS prognostic factors. The primary endpoint was OS. Results: 404 patients were included; 120 of them were LTS. Patients were aged 61 years (range: 20-89), WHO performance status 0-1 in 86.9% and 2 in 13.1%, and Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) staging III and IV in 82.7% and 17.3% patients. Breast cancer (BRCA) status was available in 116 patients (33% mutated), including 58 LTS (36% mutated). No macroscopic residual disease was observed in 58.4% patients. First-line platinum-based chemotherapy plus paclitaxel was administered in 80.4% of patients (median: six cycles (range: 1-14)). After a 9 point 3-year follow-up, median OS was four years (95% CI: 3.6-4.5). The CPS at five years after surviving one year was 42.8% (95% CI: 35.3-48.3); it increased to 81.7% (95% CI: 75.5-87.8) after four survived years. Progression-free interval>18 months was the only LTS prognostic factor in the multivariable analysis (hazard ratio (HR) = 0.23; 95% CI: 0.13-0.40; p < 0.001). Conclusion: The CPS provided relevant and encouraging clinical information on the life expectancy of HGSOC patients who already survived a period of time after diagnosis. LTS prognostic factors are useful for clinicians and patients.