698 LOW LEVELS OF SERUM OMEGA-3 POLYUNSATURATED FATTY ACID ARE ASSOCIATED WITH TUMOR AGGRESSIVENESS AND POOR PROGNOSIS IN RENAL CELL CARCINOMA

INTRODUCTION AND OBJECTIVES: Epidemiological and preclinical studies have revealed that the polyunsaturated omega-3 fatty acids alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), have anticancer properties. Omega-3 fatty acids are acquired by humans mainly through the consumption of cold-water fish products. The risk and progression of renal cell carcinoma is known to be influenced by many environmental factors, including dietary factors. In the present study, we examined the distribution profile of serum fatty acid in patients with renal cell carcinoma and investigated its relationship between pathological parameters and clinical outcome. METHODS: A total of 113 patients (89 males and 24 females) who underwent surgical treatment for renal cell carcinoma at our institute were included in this study. The levels of fatty acids in fasted serum samples collected in the morning of the day of operation were measured by a transesterification method and distribution profile of each patient was examined. This study was conducted under permission of the ethics committee of our institute. RESULTS: Neither the distribution of omega-3 fatty acids nor the distribution of omega-6 fatty acids was associated with any pathological parameters. None of the levels of constituents of omega-6 fatty acids, such as linoleic acid or arachidonic acid, were associated any pathological parameters. The percentage of ALA in T1-2 patients (0.72 0.19%), however, was significantly higher than that in T3-4 patients (0.61 0.17%, p 0.02). Moreover, the percentage of DHA in N0M0 patients (3.97 1.31%) was significantly higher than that in patients with nodal involvement and/or distant metastasis (3.26 1.02%, p 0.04). The proportion of omega-6 fatty acids had no impact on cancer-specific survival but, patients with a higher proportion of omega-3 fatty acids had significantly better cancer-specific survival than those with a lower proportion of omega-3 fatty acids (p 0.04). CONCLUSIONS: Our results suggest that the serum omega-3 fatty acids distribution profile could be a novel predictor of tumor aggressiveness and prognosis in renal cell carcinoma.