Prognostic Impact of Fatty Acid Synthase Expression in Upper Urinary Tract Urothelial Carcinoma

Objective: Fatty acid synthase has been shown to be highly expressed in various types of cancers with increased tumour aggressiveness. In this study we examined the level of fatty acid synthase expression in surgically resected upper urinary tract urothelial carcinoma specimens and evaluated the relations between fatty acid synthase expression and the patients' pathological features and clinical outcomes. Methods: Sections of paraffin-embedded tumour specimens from 113 patients who underwent surgical treatment for upper urinary tract urothelial carcinoma were immunostained with a polyclonal fatty acid synthase antibody, and a tumour was considered to have high fatty acid synthase expression if >50% of the cancer cells stained with moderate-to-strong intensity. Associations between fatty acid synthase expression and the patients' pathological parameters and survival were analyzed statistically. Results: During the follow-up time (median: 46.8 months), 61 patients (54.0%) had recurrence and 17 (15.0%) died of upper urinary tract urothelial carcinoma. High fatty acid synthase expression was significantly associated with high tumour grade (P = 0.0273). Patients with high fatty acid synthase expression had significantly worse recurrence-free survival and extravesical-recurrence-free survival than those with low fatty acid synthase expression (P = 0.0171, P = 0.0228, respectively). In multivariate analysis, high fatty acid synthase expression was an independent predictor of shortened recurrence-free survival (P = 0.0220, hazard ratio (HR) = 1.970). Conclusions: Fatty acid synthase expression in upper urinary tract urothelial carcinoma is an independent predictor for tumour recurrence. Patients with high fatty acid synthase expression in upper urinary tract urothelial carcinoma should be followed carefully and adjuvant therapy for them should be considered. Keywords: fatty acid synthase, upper urinary tract urothelial carcinoma, prognosis