Decreased prostatic arachidonic acid in human prostatic carcinoma.

OBJECTIVE: To measure prostatic and blood fatty acid composition in a large group of patients undergoing prostatectomy for benign or malignant prostate disease, as there is evidence linking arachidonic acid metabolism and prostate cancer through its role as an eicosanoid precursor, and earlier studies showed lower prostatic arachidonic acid content in a few patients. PATIENTS AND METHODS: Prostatic phospholipid fatty acid composition was determined in prostate tissue from 173 patients undergoing prostate surgery, i.e. radical prostatectomy, cystoprostatectomy or transurethral resection (TURP). Blood fatty acid composition was determined in 99 of these patients and in 85 undergoing prostatic needle biopsy. RESULTS: There was a significantly lower percentage of arachidonic acid in malignant than in benign portions of the prostate (15.2% vs 17%) in all patients assessed. The changes were greatest in those undergoing TURP for known prostate cancer (13.4% vs 17.2%), these patients having the greatest proportion of malignancy in the specimens. There were no consistent changes in blood fatty acid composition. CONCLUSION: This is the first prospective study of arachidonic acids levels involving many consecutive patients undergoing prostate surgery for either benign or malignant disease. The lower prostatic arachidonic acid level is probably a result of the increased use of arachidonic acid for producing prostaglandins and/or leukotrienes. Further understanding of the cause and/or consequence of this finding might lead to a better understanding of prostate cancer.