Effect of neoadjuvant chemotherapy on platinum resistance in stage IIIC and IV epithelial ovarian cancer

It remains controversial whether neoadjuvant chemotherapy (NACT) followed by interval debulking surgery (IDS) induces chemoresistance in advanced epithelial ovarian cancer (EOC) compared with primary debulking surgery (PDS). The aim of this study was to compare platinum-resistant recurrence following treatment with NACT-IDS or PDS in patients with stage IIIC and IV EOC.We retrospectively reviewed the records of 341 patients who underwent PDS or NACT-IDS for Federation of Gynecology and Obstetrics stage IIIC or IV EOC between March 1990 and December 2010. Risk factors of platinum resistance, including NACT, postoperative residual tumor size, and various clinicopathological factors, were evaluated by univariate and multivariate logistic regression analyses. Survival analysis was performed by the Kaplan-Meier method and Cox regression modeling to measure overall survival (OS).Of 341 patients, 58 (17.0%) underwent NACT-IDS and 283 (83.0%) were treated with PDS. Twenty-nine (50.0%) patients developed platinum-resistant disease at first relapse after NACT-IDS and 99 (35.0%) patients recurred after PDS (P = 0.033). In the multivariate logistic regression analyses, NACT-IDS and postoperative residual tumor mass >1 cm were risk factors for platinum-resistant recurrence (adjusted odds ratios 2.950 and 2.915; 95% confidence intervals [CIs] 1.572-5.537 and 1.780-4.771, P = 0.001 and 0.000, respectively). Postoperative residual tumor mass >1 cm and platinum-resistant disease were significantly correlated with shorter OS (adjusted hazard ratios 1.579 and 4.078; 95% CI 1.193-2.089 and 3.074-5.412, P = 0.001 and 0.000, respectively), whereas NACT-IDS did not extend OS.NACT-IDS increases the risk of platinum-resistant recurrence in patients with stage IIIC and IV EOC.