The impact of interval cytoreduction and age in advanced-stage ovarian cancer: A GOG ancillary study.

Abstract

5056 Background: To determine if an age group exists for which interval cytoreductive surgery (ICS) in patients with suboptimal residual disease at primary surgery influences progression free survival (PFS) and overall survival (OS) among women with advanced ovarian cancer treated on GOG 182. Methods: GOG 182 was a prospective, randomized trial of first-line chemotherapy in patients with advanced ovarian cancer. Patients with both optimal and suboptimal residual disease were included, and those with suboptimal residual were considered for ICS, with intent registered and stratified prior to randomization. Patients were randomized to one of five chemotherapy arms, employing combinations of either two or three agents delivered intravenously, with a control arm of paclitaxel and carboplatin. A retrospective analysis was approved by the GOG Ancillary Study Committee to investigate the influence of age on treatment and outcomes. In that analysis, Cox regression was used to identify independent prognostic factors and estimate their covariate effects on the adjusted PFS and OS of patients with suboptimal residual disease. Statistical significance was set at p<0.05. Results: Among the entire eligible study population, 28% (n=1,042) were registered with suboptimal residual disease (> 1 cm) and 109 of these patients elected to undergo ICS. Hazard ratios (HR) were determined for patients undergoing ICS with reference to patients with suboptimal disease not undergoing ICS. Based on the most current follow-up data, the HR for progression or death was not statistically different between the groups, but the HR of death alone was significant at 0.72 (95% CI: 0.57–0.92, p=0.008). There was no significant association of age with ICS in either the PFS or the OS model. Conclusions: In this trial, a patient’s age did not influence the effect of ICS on PFS or OS. There is no demonstrable benefit in PFS associated with ICS, but there was a statistically significant improvement in OS. To elucidate this finding, further study is warranted, likely in the form of a meta-analysis incorporating data from other prospective trials.