Role of anterior prostatic fat pad dissection for extended lymphadenectomy in prostate cancer: a non-randomized study of 100 patients

Presence of lymph nodes and metastasis within prostatic anterior fat pad in radical prostatectomy patients: A single Chinese institution experience and literature review

INTRODUCTION

Limited data from China, aim to investigate the incidence and the risk fctors of lymph node metastases in the prostatic anterior fat pad (PAFP).

MATERIAL AND METHODS

Patients underwent radical prostatectomy (RP) were enrolled between March 2020 to December 2022 at a single institution. Separate pathological analysis of PAFP was performed within this area. Univariate analysis and Multivariate analysis were performed to determine the risk factor of PAFP metastasis.

RESULT

A total of 255 patients were included. The study revealed an average age of 67.72 ± 7.07 years, with a mean total tumor volume of 41.54 ± 23.79 mL, and an average Pre-op PSA of 16.85 ng/mL. Clinical T stage was divided into T2, T3, and T4 (226, 25, 4 cases, respectively), while the Clinical M stage was categorized as M0 and M1 (248 and 7 cases, respectively). Out of the patients with PAFP, 19 (7.45 %) had lymph node in PAFP, and 3 (1.18 %) patients had metastases. In the univariate and multivariate analysis, Clinical M stage and anterior primary tumor were found to be a significant high-risk factor. Among the other 15 studies, six examined the risk factors associated with it, including anterior tumors, higher tumour volume, intermediate or high risk prostate cancer.

CONCLUSION

Due to the low proportion of lymph node involvement (7.45 %) and rare tumor metastasis (1.18 %), routine separate pathological analysis of PAFP is not recommended in all RP patients unless there are anterior tumors, higher tumor volume, or intermediate/high risk prostate cancer.

The impact of histopathological analysis of anterior peri-prostatic fat in radical prostatectomy patients

Objective:

To determine the usefulness of histopathological analysis of peri-prostatic fat in a cohort of prostate cancer patients undergoing radical prostatectomy (RP) in an Australian regional centre. During RP, removal of the anterior peri-prostatic fat (APPF) is commonly undertaken; some surgeons routinely request histopathological analysis of this specimen. Previously published data show positive cancer detection in peri-prostatic fat in 0–2.5% of specimens and positive yields are mostly detected in patients with adverse pathological features.

Subjects and methods:

All patients undergoing RP in a regional urology unit in Queensland were identified. Pathology results were examined retrospectively to determine the rate of cancer involvement in APPF specimens and medical records were reviewed to assess any clinical impact.

Results:

APPF was sent for pathological analysis in 270/298 (90%) of patients undergoing RP. Prostate cancer was detected in one sample containing a single involved lymph node in a patient with Gleason 5 + 4 = 9 prostate cancer and pathological stage pT3bN1R1Mx. The presence of the cancer in the APPF did not affect the decision to offer adjuvant radiotherapy.

Conclusion:

In our population, we have identified a positive cancer yield of 0.3% in APPF specimens. When combined with all previously published series, we found positive cancer detection in 72/7391 (1%) specimens, and most patients with positive fat involvement had adverse pre-operative and final pathological features. Surgeons may consider omitting sending APPF specimens for analysis based on the low yield with little additional staging information. If surgeons continue this practice, they should consider selectively requesting analysis in intermediate- and high-risk patients.

Level of evidence:

2b

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.