Neoadjuvant chemotherapy in advanced-stage epithelial ovarian, fallopian tube, and primary peritoneal carcinoma: Do number of cycles matter?

Abstract

Objectives: There has been a growing body of literature supporting the use of neoadjuvant chemotherapy (NACT) in advanced-stage epithelial ovarian cancer (EOC); however, there are no data to inform the optimal number of cycles before interval debulking surgery (IDS). The objective of this study was to determine if the number of cycles of NACT has an impact on clinical outcomes in advanced EOC. Methods: Institutional review board approval was obtained. From January 2007 to December 2014, patients treated with either primary debulking surgery (PDS) or NACT followed by IDS were included. Patient charts were abstracted for demographic information, treatment characteristics, and patient outcomes. Statistical tests were performed with the Fisher exact, Pearson χ2, and simple linear regression using STATA version 14. P = .05 was considered statistically significant. Results: A total of 239 patients were identified, 141 in the PDS group and 98 in the NACT group. We compared patients who received ≤3 cycles of NACT before IDS with those who had ≥4 cycles. In the ≤3-cycles cohort, 77.2% achieved R0 status compared with 61.8% in the ≥4-cycles cohort. There was no difference in the rate of optimal debulking between groups (P = .18). When comparing both NACT cohorts with the PDS group, the number of cycles was associated with debulking status. The PDS group had a 40.4% R0 rate, which was significantly lower than that in the ≤3-cycles cohort (P = .006) and the ≥4-cycles cohort (P < .001). The median progression-free interval (PFI) was not different between the 2 NACT cohorts. The median PFI in the ≤3-cycles group was 13.4 months and in the ≥4-cycles group was 7.7 months (P = .993). Complete pathologic response was achieved in 3 patients (3.1%), who received 4, 5, and 6 of cycles of NACT, respectively, and 16 patients (16.7%) had microscopic disease of 5 mm or less. The pathologic response was a predictor of PFI, with a median PFI of 34.4 months in the complete pathologic response group, 11.1 in the group with 5 mm or less disease versus 7.3 in the group with more than 5 mm disease (P = .0002). Conclusions: The number of cycles of NACT before IDS did not affect optimal debulking rates or PFI after primary treatment, but resulted in a higher R0 resection rate than PDS. Additionally, pathologic response rates may be a surrogate marker for survival. Prospective study is warranted to better evaluate prognosticators for outcomes in patients treated with NACT.