Importance: Uncertainty remains about the relative benefits of primary cytoreductive surgery (PCS) vs neoadjuvant chemotherapy (NACT) for advanced-stage epithelial ovarian cancer (EOC).
Objective: To compare overall survival of PCS vs NACT in a large national population of women with advanced-stage EOC.
Design, setting, and participants: Retrospective cohort study of women with stage IIIC and IV EOC diagnosed between 2003 and 2011 treated at hospitals across the United States reporting to the National Cancer Data Base. We focused on patients 70 years or younger with a Charlson comorbidity index of 0 who were likely candidates for either treatment.
Exposures: Initial treatment approach of PCS vs NACT, examined using an intent-to-treat analysis.
Main outcomes and measures: Overall survival, defined as months from cancer diagnosis to death or date of the last contact. We used propensity score matching to compare similar women who underwent PCS and NACT. The association of treatment approach with overall survival was assessed using the Kaplan-Meier method and the log-rank test. We assessed whether the findings were influenced by differences in the prevalence of an unobserved confounder, such as limited performance status (Eastern Cooperative Oncology Group 1-2), preoperative disease burden, and BRCA status.
Results: Among 22 962 patients (mean [SD] age, 56.12 [9.38] years), 19 836 (86.4%) received PCS and 3126 (13.6%) underwent NACT. We matched 2935 patients treated with NACT with similar patients who received PCS. The median follow-up was 56.5 (95% CI, 54.5-59.2) months in the PCS group and 56.3 (95% CI, 54.5-59.8) months in the NACT group in the propensity-matched cohort. Among propensity score-matched groups, the median overall survival was 37.3 (95% CI, 35.2-38.7) months in the PCS group and 32.1 (95% CI, 30.8-34.1) months in the NACT group (P < .001). However, if the NACT group had a higher proportion of women with performance statuses of 1 to 2 compared with those who underwent PCS (60% vs 50%), the association of PCS and improved survival would not be statistically significant.
Conclusions and relevance: Primary cytoreductive surgery was associated with improved survival compared with NACT in otherwise healthy women with advanced-stage epithelial ovarian cancer aged 70 years or younger. The lower survival in women who received NACT could be explained by a higher prevalence of limited performance status in women undergoing NACT.