Periprostatic lymph node metastasis in prostate cancer and its clinical significance

Abstract

Aims: To evaluate the potential of periprostatic lymph node (LN) as a staging indicator, particularly with the use of methods for enhanced detection of micrometastasis.

Methods and results: We retrieved cases with periprostatic LN from radical prostatectomy specimens accrued between 1997 and 2007 at our institution. Twenty-one (0.8%) of 2663 radical prostatectomy specimens had periprostatic LNs (total number of LNs = 22). LN size ranged from 0.8 to 4.7 mm. Most of the periprostatic LNs were located close to the posterior base. Seven (32%) of 22 LNs were involved by metastatic prostate cancer (PCa), including five detected on routine haematoxylin and ceosin slides and an additional two detected only by immunohistochemistry. Cases with periprostatic LNs had a significantly higher metastatic rate (29%; six of 21) compared to those with pelvic LNs sampled at radical prostectatomy in our institution (1.9%). When compared to cases with negative periprostatic LNs (n = 15), the tumour characteristics of cases with metastatic periprostatic LNs (n = 6) included higher tumour volume, Gleason score, stage and a greater propensity for prostate-specific antigen (PSA) recurrence.

Conclusions: Despite their infrequent identification, periprostatic LNs if detected in the radical prostatectomy specimen should be evaluated with greater scrutiny (step sections and/or immunohistochemical studies) to evaluate their prognostic potential.