INCREASED EXPRESSION OF FATTY-ACID SYNTHASE (OA-519) IN OVARIAN NEOPLASMS PREDICTS SHORTER SURVIVAL

Certain cancers exhibit derangement of de novo fatty acid biosynthesis , manifested as overexpression and hyperactivity of the lipogenic enzy me fatty acid synthase (FAS). Correlation of elevated FAS with high tu mor grade and advanced stage in primary breast, prostate, and colorect al cancers has drawn attention to the enzyme as a possible marker of p oor prognosis. To find a similar utility of FAS in ovarian neoplasms, we compared FAS expression in 68 ovarian tumors with their histologica l features and clinical outcome. Immunohistochemical localization of F AS was observed in 48 (71%) cases in which staining was either focal ( defined as positive staining in 1% to 20% of cells) or multifocal/diff use (positive staining in >20% of cells). Most (83%) of the 48 cases w ere represented by endometrioid, serous, or mucinous carcinomas and ma lignant mixed mullerian tumors (MMMTs). In contrast, ovarian adenomas and tumors of low malignant potential (LMPs) contained little or no FA S. Association between FAS expression and histological diagnosis was s tatistically significant. The extent of FAS immunostaining was also pr edictive of prognosis. Among all patients with ovarian malignancies (i ncluding LMPs), median survival was 64.8 months, when their tumors exh ibited no or focal immunostaining for FAS, as opposed to 31.2 months, when staining was multifocal/diffuse (P = .005). Similar median surviv al values were obtained when cases were limited to endometrioid, serou s, and mucinous carcinomas. Short-term survival at 1 and 2 years was s ignificantly higher in patients whose tumors showed no or focal expres sion of FAS compared with multifocal/diffuse expression. Thus, elevate d FAS may serve as an independent marker for predicting poor clinical outcome in patients with ovarian cancer. Copyright (C) 1997 by W.B. Sa unders Company.