Prognostic evaluation of tumour type and other histopathological characteristics in advanced epithelial ovarian cancer, treated with surgery and paclitaxel/carboplatin chemotherapy: cell type is the most useful prognostic factor.

AIM: Ovarian carcinomas have been classified into types I and II according to the hypothesised mode of carcinogenesis and molecular characteristics. The prognostic significance of this classification has not been studied. PATIENTS AND METHODS: Five hundred and sixty-eight patients with histologically confirmed, ovarian, fallopian tube or peritoneal carcinomas, international federation of gynecology and obstetrics (FIGO) stages IIC-IV, treated with paclitaxel/platinum following cytoreductive surgery, were included in this analysis. Type I included low-grade serous, mucinous, endometrioid and clear-cell and type II high-grade serous, unspecified adenocarcinomas and undifferentiated carcinomas.
RESULTS: Median overall survival (OS) was 49 months for type I versus 45 for type II (p=0.576). In contrast to type II, there was considerable prognostic heterogeneity among the subtypes included in type I. Cox regression analysis showed that cell-type classification: low-grade serous, mucinous, endometrioid, clear-cell, type II (high-grade serous, unspecified adenocarcinomas, undifferentiated carcinoma) was an independent predictor of survival (respective median OS 121 versus 15 versus 64 versus 29 versus 45 months, p=0.003). On the contrary, histopathological subtype or tumour type (I versus II) did not offer additional prognostic information.
CONCLUSION: The proposed model of ovarian tumourigenesis does not reflect tumour behaviour in advanced disease. Tumour-cell type is the most relevant histopathological prognostic factor in advanced ovarian cancer treated with platinum/paclitaxel.