Can Anterior Prostatic Fat Harbor Prostate Cancer Metastasis? A Prospective Cohort Study

Objectives: Traditionally anterior prostatic fat (APF) hasn't been included in pelvic lymph node (LN) dissection templates following radical prostatectomy. In this study we evaluate the incidence of lymphoid tissue in the APF and the incidence of LN metastasis in APF in patients who have undergone robotic-assisted laparoscopic radical prostatectomy (RALP). Methods: A prospective database of RALP has been maintained between January 2010 and September 2015. APF is routinely excised and sent separately for histopathological evaluation to identify lymphoid tissue and metastatic prostate cancer. Results: A total of 629 underwent RALP. Forty-six (7.3%) of the patients had lymphoid tissue on histopathological evaluation. Two patients had meta-static disease. Both patients with positive LNs were intermediate risk on pre-operative evolution (A-PSA 16.6 ng/ml, Gleason 3 + 4; B PSA 7.3 ng/ml, Gleason 4 + 3) and upgraded on final prostate pathological evaluation to high risk disease (A-Gleason 4 + 5, pT3b, B-Gleason 4 + 3, pT4). Conclusion: There appears to be lymphatic drainage to the APF from the prostate. Hence APF should be included in pelvic LN dissection templates when lymphadenectomy is contemplated in patients undergoing radical prostatectomy.