Complete cytoreduction: Is epithelial ovarian cancer confined to the pelvis biologically different from bulky abdominal disease?

Objectives. The aim of this study was to determine whether site and size of tumor masses prior to complete surgical cytoreduction affect outcome survival. Methods. A retrospective review was performed of 53 women with stage II and III epithelial ovarian cancer following complete surgical cytoreduction. Results. Fifteen cases (28%) were classified as stage II and the remaining 38 cases (72%) as stage III. The overall median survival was 58 months with overall 2- and 5-year survivals of 76 and 42%, respectively. On univariate analysis, women with well differentiated tumors did significantly better than those with moderately or poorly differentiated tumours (P = 0.0009). FIGO stage did not reach statistical significance (P = 0.066). On multivariate analysis, comparing patient's age, previous history of pelvic surgery, previous history of malignancy, performance of lymphadenectomy for visibly/palpably enlarged nodes, performance of bowel resection, presence of concomitant tumors, positive pelvic and/or paraaortic lymph nodes, histological type, histological grade, and FIGO stage, only histological grade remained an independent variable affecting outcome survival (P = 0.0004; FIGO stage, P = 0.22) (hazard ratio = 6.5: well versus poor differentiation, 95% confidence interval, 1.7-25.5). Conclusion. When surgical cytoreduction to no visible disease has been achieved in women with stage II and III epithelial ovarian cancer, FIGO stage, i.e., site and size of tumor masses prior to surgical cytoreduction, does not appear to influence outcome survival. The aggressiveness of the remaining microscopic disease would seem to be determined largely by histological grade. Bearing in mind the retrospective nature of this study and the relatively small cohort of patients, the results would appear to suggest that it is unlikely that there are any other significant parameters (hidden factors) affecting tumor biology which are independent of tumor grade in these patients. A possible implication of this result is that complete surgical cytoreduction confers a survival benefit by producing a biologically more homogenous tumor. (C) 2000 Academic Press.