Does anterior prostatic fat tissue removed during robotic radical prostatectomy contain any lymph nodes?

Impact of prostatic anterior fat pads with lymph node staging in prostate cancer

Background: Several reports have revealed the presence of lymph nodes in the prostatic anterior fat pad (PAFP). To date, no study has described the characteristics of Taiwanese patients harboring PAFP lymph nodes with metastatic prostate cancer involvement.

Method: Between December 2006 and May 2015, a total of 849 consecutive patients underwent robot-assisted laparoscopic radical prostatectomy with PAFP dissection. Pathological examination of the dissected PAFP was conducted to assess the presence of lymphoid tissue and prostate cancer involvement.

Results: Of the 849 patients, 76 (9.0%) had 1-3 PAFP lymph nodes. Moreover, 11 (1.3%) of the 76 patients had positive lymph node metastases of prostate cancer in the PAFP; 5 (0.6%) of the 11 patients, who had negative pelvic lymph node involvement, were upstaged because of positive metastases in PAFP lymph nodes. Among the 76 patients having PAFP lymph nodes, metastatic lymph nodes were associated with the clinical T stage, preoperative Gleason score, pathological T stage, and pathological N stage (p < 0.001). Patients with pathological seminal vesicle invasion and a higher surgical Gleason score also exhibited PAFP lymph node metastases (p < 0.005).

Conclusion: Our data show that 9.0% of patients had PAFP lymph nodes and that 1.3% had prostate cancer metastases. Additionally, 0.6% of patients were upstaged because of positive metastases in PAFP lymph nodes. Because of the pathological analysis of the PAFP, a few patients were upstaged. Thus, routine pathological analysis of the PAFP should only be conducted for those with higher preoperative prostate-specific antigen, higher Gleason score, and advanced T stage observations.

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.