INTRODUCTION: The objective of this study was to determine the impact of intra-abdominal residual disease size, type (carcinomatosis, tumor mass or both), and location (upper/lower abdominal/both) on overall survival in women with Federation of Gynecology and Obstetrics (FIGO) stage IIIB-IIIC vs stage IV epithelial ovarian cancer who underwent primary debulking surgery.

MATERIAL AND METHODS: Altogether 2092 women diagnosed with advanced epithelial ovarian cancer undergoing primary debulking surgery in Denmark during 2005-2016 were identified in the Danish Gynecological Cancer Database. The impact of residual disease size, type, and location were evaluated using univariate and multivariate analyses.

RESULTS: Complete cytoreduction (residual disease = 0) was achieved in 47.3% and 38.4% of women with stage IIIB-IIIC and IV epithelial ovarian cancer, respectively. A benefit in overall survival was observed in women with residual disease = 0 compared with women with residual disease, and among women with residual disease ≤1 cm compared with residual disease >2 cm in both stages IIIB-IIIC and stage IV in multivariate analyses. Multivariate analyses showed an inferior overall survival for women with both residual carcinomatosis and residual tumor mass compared with those with residual tumor mass or residual carcinomatosis only for stage IIIB-IIIC and IV, and an inferior overall survival for women with residual disease located in both the upper and lower abdomen compared with residual disease in the upper abdomen only in stages IIIB-IIIC.

CONCLUSIONS: Our results confirm the positive prognostic impact of both complete cytoreduction and residual disease ≤1 cm in stages IIIB-IIIC as well as stage IV epithelial ovarian cancer. Women with stage IV do benefit from cytoreductive surgery and should be considered for primary debulking surgery, if residual disease = 0 can initially be expected.