Objective: To correlate the histopathological characteristics of lymph node metastases in prostate cancer with cancer-specific survival (CSS).
Patients and methods: The histopathological slides from 142 patients who had had a pelvic lymph node dissection for node-positive prostate cancer were reviewed. For each patient we recorded the number of lymph nodes removed, the number of positive nodes, the diameter of the largest metastasis and extranodal extension (ENE). The lymph node metastases were graded according to the Gleason system. These variables were correlated with CSS.
Results: The mean age of the patients was 62.4 years and the mean preoperative prostate-specific antigen level was 40.2 ng/mL. The median follow-up was 77.5 months, and the median overall and CSS were 91 and 112 months, respectively. On univariable analysis the following variables correlated with poor CSS: a nodal Gleason score of >7 (hazard ratio 2.4, P < 0.001), a diameter of the largest metastasis of >3 mm (2.2, P = 0.025), more than two lymph node metastases (2.0, P = 0.003), and ENE in more than one lymph node (1.9, P = 0.014). Multivariable analysis showed only the nodal Gleason score and the diameter of the largest metastasis to be independent predictors of CSS (1.8, P = 0.021, and 2.2, P = 0.046, respectively).
Conclusion: The histopathological characteristics of lymph node metastases in prostate cancer have predictive value for the clinical outcome. The nodal Gleason score and the diameter of the largest metastasis are independent predictors of survival.