Anatomical extent of lymph node dissection: impact on men with clinically localized prostate cancer.

PURPOSE

This study evaluates the influence of the anatomical extent of pelvic lymph node dissection performed at radical prostatectomy on lymph node yield, staging accuracy and time to prostate specific antigen progression.

MATERIALS AND METHODS

Between February 1992 and April 2003, 2 surgeons at 1 hospital performed 2,135 and 1,865 radical prostatectomies with pelvic lymph node dissection, respectively. One surgeon routinely performed an extended lymph node dissection while the second surgeon performed a limited pelvic lymphadenectomy. The number of lymph nodes extracted and the number of patients with positive lymph nodes detected were analyzed and compared. Kaplan-Meier analysis was used to compare the biochemical recurrence-free survival between the 2 groups of patients with occult nodal disease.

RESULTS

Extended lymph node dissection removed more lymph nodes (mean 11.6 vs 8.9, p<0.0001) and detected more lymph node positive disease (3.2% vs 1.1%, p<0.0001) than the more anatomically limited technique. This finding held true for patients across all pathology groups. Among men with lymph node positive disease involving less than 15% of extracted nodes, the 5-year prostate specific antigen progression-free rate for extended lymph node dissection was 43% versus 10% for the more limited lymph node dissection (p = 0.01).

CONCLUSIONS

Compared to limited lymph node dissection, extended pelvic lymphadenectomy appears to identify men with positive lymph nodes more frequently. A significant benefit in biochemical recurrence-free survival may exist for certain subgroups undergoing the extended dissection. However, because the results may be influenced by stage migration, longer followup is necessary to determine whether the apparent therapeutic effect persists.