The impact of disease distribution on survival in patients with stage III epithelial ovarian cancer cytoreduced to microscopic residual: a Gynecologic Oncology Group study.

OBJECTIVE

To assess the survival impact of initial disease distribution on patients with stage III epithelial ovarian cancer (EOC) cytoreduced to microscopic residual.

METHODS

We reviewed data from 417 stage III EOC patients cytoreduced to microscopic disease and given adjuvant intravenous platinum/paclitaxel on one of three randomized Gynecologic Oncology Group (GOG) trials. We subdivided patients into three groups based on preoperative disease burden: (1) minimal disease (MD) defined by pelvic tumor and retroperitoneal metastasis (2) abdominal peritoneal disease (APD) with disease limited to the pelvis, retroperitoneum, lower abdomen and omentum; and (3) upper abdominal disease (UAD) with disease affecting the diaphragm, spleen, liver or pancreas. We assessed the survival impact of potential prognostic factors, focusing on initial disease distribution using a proportional hazards model and estimated Kaplan-Meier survival curves.

RESULTS

The study groups had similar clinicopathologic characteristics. Median overall survival (OS) was not reached in MD patients compared to 80 and 56 months in the APD and UAD groups (P<0.05). The five-year survival percentages for MD, APD, and UAD were 67%, 63%, and 45%. In multivariate analysis, the UAD group had a significantly worse prognosis than MD and APD both individually and combined (Progression Free Survival (PFS) Hazards Ratio (HR) 1.44; P=0.008 and OS HR 1.77; P=0.0004 compared to MD+APD).

CONCLUSION

Stage III EOC patients with initial disease in the upper abdomen have a worse prognosis despite cytoreductive surgery to microscopic residual implying that factors beyond cytoreductive effort are important in predicting survival.