Investigating the timing and site of recurrence for ovarian clear cell carcinoma: Analysis of the JGOG/GCIG trial-JGOG 3017-A3

Abstract

BackgroundThis study was conducted to determine the optimal monitoring after initial treatment of ovarian clear cell carcinoma (OCCC) using data from patients enrolled in the Japanese Gynecologic Oncology Group (JGOG) 3017 study. The JGOG study evaluated the efficacy of an irinotecan and cisplatin combination regimen compared with that of a paclitaxel and carboplatin regimen for OCCC patients who underwent primary surgery. MethodsYielding 619 total patients in this study, to analyze progression-free and overall survival, the hazards over time were estimated using kernel smoothing curves to identify the peak of event occurrence. The number of progression events was summed by progression site, and the cumulative incidence proportion was estimated for the major progression sites, considering competing risks. ResultsThe peak hazard for progression or death was observed at 12 months post-treatment, and most events were observed by 24 months. The hazard for death peaked at 18 months post-treatment, with most events being observed by 48 months. The hazard for lung, liver, and spleen metastases remained constant for 18 months post-treatment, with a decreasing trend thereafter; most events were observed by 18 months. The hazard for peritoneal dissemination was constant for 12 months, with a decreasing trend thereafter, with most exacerbations observed by 24 months. The risk of pelvic recurrence peaked at 6 months, with most exacerbations observed by 24 months. DiscussionThe incidence of progression events for OCCC peaked at 12 months and most progression events occurred within 24 months. Close follow-up for the initial 24 months post-treatment and fewer visits thereafter may be acceptable. However, closely monitoring symptoms and examining patients based on differences in progression rates at different sites may be important.