Impact on survival of surgically defined favorable responses to salvage intraperitoneal chemotherapy in small-volume residual ovarian cancer

Purpose: To evaluate the impact on survival of the attainment of surgically defined favorable responses (S-R) to salvage intraperitoneal (IP) chemotherapy after initial systemic cytotoxic drug delivery. Patients and Methods: We examined the survival of patients who were treated on one of three phase II IP trials that were conducted at the Memorial Sloan-Kettering Cancer Center. A total of 58 patients whose largest residual tumor masses measured ≤ 0.5 cm in maximum diameter at the initiation of this salvage therapy were assessable for response, 28 of whom (48%) demonstrated a S-R, which included 19 (33%) who achieved a surgically defined complete response (S-CR). Results: With a median follow-up of 43+ months (range, 33+ to 58+ months) from the initiation of IP therapy, 12 of 19 (63%) have recurred. The median duration of S-CR for the 10 patients with microscopic residual disease was 32 months compared with 15 months for the nine patients with macroscopic residual disease (largest tumor mass ≤ 0.5 cm; P > .1). For patients with microscopic residual disease who experienced a S-CR (n = 10) after salvage IP therapy, the median overall survival from the initiation of therapy has not been reached, but will exceed 4 years compared with a 25-month median survival for the nonresponding patients (n = 13; P = .004). The median survival for the 18 patients with small-volume macroscopic disease who responded to therapy was 40 months compared with 19 months for the nonresponders (P = .009). Conclusion: Although the results of this evaluation are encouraging and suggest that the attainment of a S-R, particularly a S-CR, after IP chemotherapy may result in a clinically meaningful favorable impact on survival, a randomized controlled trial will be required to address definitively this important issue.