Secondary cytoreduction for ovarian cancer relapse: results from the high surgical quality, multi-center "Surgery in Recurrent Ovarian Cancer Research Consortium (SURROC-CON)".

To evaluate the effect of secondary cytoreductive surgery on survival outcomes in patients with ovarian cancer recurring more than 6 months after first-line therapy, treated at specialized high-volume centers. Exploratory data analysis of prospective registries from 5 cancer centers in Europe and the USA (2004-2022). Patients with a first recurrence of any epithelial ovarian cancer >6 months following first-line chemotherapy were eligible. To minimize selection bias, all eligible patients who received any anti-cancer treatment were evaluated. Overall and progression-free survival were calculated from the date of recurrence. All statistical tests were 2-sided. Of 3109 included patients, 38.7% underwent secondary cytoreduction; 83.6% achieved complete clearance. Mean and median platinum-free intervals were 33 and 23 months, respectively (range; 6-300). All 3 scores (Arbeitsgemeinschaft Gynäkologische Onkologie, iMODEL, and Memorial Sloan Kettering criteria) had similar predictive values for complete clearance. Median overall survival was 81 months (95% confidence interval 73 to 88) after complete clearance versus 39 months (95% confidence interval 33 to 44) with residual disease (p <.001). Median overall survival with chemotherapy alone was 34 months (95% confidence interval 33 to 36). BRCA1/2 mutations were associated with significantly improved progression-free survival after secondary cytoreduction (27.4 vs. 21.3 months, p <.0021) but not overall survival and did not retain their effect in the complete gross resection cohort. Timing of initial cytoreduction did not significantly affect the benefit of secondary cytoreduction. Median overall survival without previous maintenance therapy was 73 months (95% confidence interval 65 to 79) versus 55 months (95% confidence interval 47 to 63) after previous bevacizumab versus 44 months (95% confidence interval 32 to 56) after previous poly(adenosine diphosphate-ribose) polymerase inhibitors (p =.0056). Unifocal relapse, platinum-free interval > 16 months, age < 75 years, CA125 < 105 U/mL, Eastern Cooperative Oncology Group performance status 0, initial International Federation of Gynecology and Obstetrics-stage I/II, <500 mL ascites, non-mucinous histologies, and complete gross resection were associated with significantly improved overall survival post-secondary cytoreduction. Secondary cytoreductive surgery performed at specialized high-volume centers was associated with substantially prolonged overall survival compared with chemotherapy alone, particularly when complete gross resection was achieved. Neither BRCA status nor timing of initial cytoreduction significantly influenced this benefit, whereas prior maintenance therapy with poly(adenosine diphosphate-ribose) polymerase inhibitors and/or bevacizumab was associated with shorter overall survival after surgery.