Characteristics and prognostic factors of primary peritoneal cancer

Abstract

5136 Background: To compare the disease characteristics of primary peritoneal cancer (PPC) with that of ovarian cancer, and to determine the prognostic factors of peritoneal cancer. Methods: Between 1994 and 2001, histology, tumor grade, CA125 levels, lymph node status, the site(s) of metastatic disease and the residual diseases were recorded for all womwn with ovarian and PPC. Univariate and multivariate analysis were used to evaluate the effects of these prognostic factors on the outcomes of patients with PPC. Results: One-hundred ninety-three patients were analyzed. Twelve percent of patients had ovarian tumors of low malignant potential (LMP), 74% of patients had primary epithelial carcinoma of the ovary and 14% patients had PPC. The mean age of patients with PPC were older than those with ovarian cancer (70 vs. 59, respectively). More PPC were associated with advanced stages (Stage III, IV) and higher grade (95% Grade 3) compared to ovarian cancer where 66% were Stage III, IV and 68% were Grade 3. The predominant histologic cell type of PPC were of serous cell type (94%). There were no significant differences in the status of lymph nodes between the PPC and ovarian cancer. However, there were significant differences in the incidence of diaphragmatic spread (83% vs 59%, p<0.001) between the PPC and ovarian cancer. Similarly, PPC were more likely to be associated with residual tumor size>1cm than ovarian cancer (54% vs. 23%, p<0.001). Using multivariate analysis, stage, grade, ascites, and lymph node status of PPC do not seem to affect the survival, whereas degree of residual disease appear to be the most important prognostic factor for patients with PPC. Conclusions: Patients with PPC are more likely to have advanced stage disease which is higher in grade and more aggressive. The PPC are more likely to have ascites, diaphragmatic involvement, and larger residual tumors than that of ovarian cancer. The status of residual tumor size appear to be significant prognostic factors in predicting long term survivals. Therefore, aggressive tumor debulking including diaphragmatic resection may be important to improve survival of patients with PPC. No significant financial relationships to disclose.