Background: Fatty acid synthase (FAS) is a molecule found in tumor cells from breast carcinomas of patients whose prognosis is very poor. Recently, this molecule has been identified as the key enzyme in fatty acid biosynthesis. This study was done to test the strength of FAS as a prognostic indicator for disease free survival (DFS) and overall survival (OS).
Methods: Clinical records, histologic features, immunohistochemical expression of cathepsin D and c-erbB-2, and estrogen and progesterone receptor status of 110 Stage I breast carcinoma patients were all associated with FAS by a chi-square test. The patterns of DFS and OS were estimated over a ten-year follow-up period using the Kaplan-Meier method. Univariate and multivariate analysis were evaluated using a log logistic regression model. Multivariate regression analysis was based on the Cox proportional hazard model. To detect FAS, cathepsin D and c-erbB-2 expression as well as estrogen and progesterone receptor status, we used the unlabeled immunoperoxidase technique on formalin fixed, paraffin embedded tissue.
Results: FAS was significantly associated with a higher risk of recurrence because it predicted both DFS (P = 0.0001) and OS (P = 0.003) when evaluated as a continuous variable and DFS (P = 0.0001) when evaluated with other prognostic markers. Peritumoral lymphatic vessel invasion was the other most significant independent predictor for DFS (P = 0.001) and OS (P = 0.003).
Conclusions: FAS is a reliable prognostic marker to predict DFS and OS in patients with early breast cancer.