Primary cytoreductive surgery compared with neoadjuvant chemotherapy in patients with mutated advanced high grade serous ovarian cancer: 10 year survival analysis.

Objectives: Given the high response to platinum based chemotherapy in 1/2 mutated high grade serous ovarian cancers, there is uncertainty about the relative benefits of primary cytoreductive surgery versus neoadjuvant chemotherapy in this population. We aimed to compare the survival outcomes for women with 1/2 mutated high grade serous ovarian cancers undergoing either primary cytoreductive surgery or neoadjuvant chemotherapy.

Methods: We conducted a retrospective cohort study of all stage III/IV mutated high grade serous ovarian cancers treated with primary cytoreductive surgery or neoadjuvant chemotherapy at a single tertiary cancer center between 1991 and 2020. Baseline demographics, initial disease burden, surgical complexity, and survival outcomes were examined.

Results: Of 314 women with germline or somatic mutations, 194 (62%) underwent primary cytoreductive surgery and 120 (38%) underwent neoadjuvant chemotherapy followed by interval cytoreductive surgery. Those undergoing primary cytoreductive surgery were younger (median age 53 years (range 47-59) vs 59 years (50-65), p<0.001), but there were no differences in functional status or underlying comorbidities. The initial disease burden was lower (disease score high (40% vs 44%; p<0.001) but surgical complexity was higher (surgical complexity score high (18% vs 3%; p<0.001) in the primary cytoreductive surgery cohort. The rate of optimal or complete cytoreduction was similar in both groups (89% vs 90%; p=0.23) as well as the rate of poly (ADP-ribose) polymerase inhibitor use (62% vs 68%; p=0.3). The 10 year overall survival and recurrence free survival were superior in the primary cytoreductive surgery cohort (overall survival 49% vs 25%, p<0.001 and progression free survival 25% vs 10%, p<0.001). After controlling for confounders, primary cytoreductive surgery remained a significant predictor of improved overall survival (hazard ratio (HR) 0.45; 95% confidence interval (CI) 0.27 to 0.74; p=0.002) and recurrence free survival (HR 0.55; 95% CI 0.37 to 0.80; p=0.002).

Conclusions: Primary cytoreductive surgery was associated with improved survival in women with stage III/IV mutated high grade serous ovarian cancers compared with neoadjuvant chemotherapy.