Detection of micrometastatic prostate cancer cells in the lymph nodes by reverse transcriptase polymerase chain reaction is predictive of biochemical recurrence in pathological stage T2 prostate cancer

Abstract

Purpose: We evaluated whether detecting prostate cancer cells by the nested reverse transcriptase-polymerase chain reaction (RT-PCR) in lymph nodes has predictive value for serum prostate specific antigen (PSA) recurrence in patients undergoing radical prostatectomy.

Materials and methods: We assessed the presence of prostate cancer cells by RT-PCR for prostate specific membrane antigen and PSA assay in lymph nodes dissected from 38 patients with localized prostate cancer treated with radical prostatectomy. The results of nested RT-PCR assay were compared with biochemical recurrence.

Results: Nested RT-PCR was positive in the lymph nodes of 2 of 18 patients (11%) with stage pT2a and 5 of 20 (25%) with stage pT2b disease. All 7 patients had biochemical recurrence. We noted a significant difference in the Kaplan-Meier recurrence-free actuarial probability curve in those with positive and negative nested RT-PCR results for prostate specific membrane antigen, PSA and prostate specific membrane antigen-PSA in the lymph nodes (p = 3.02x10(-7), 2.23x10(-7) and 3.02x10(-7), respectively). Multivariate analysis of serum PSA, Gleason score and preoperative RT-PCR assay in peripheral blood showed that nested RT-PCR for prostate specific membrane antigen, PSA and prostate specific membrane antigen-PSA in the lymph nodes were independent predictors of recurrence (p = 0.0089, 0.0075 and 0.0089, respectively).

Conclusions: Nested RT-PCR of the lymph nodes may be a useful pretreatment prognostic test for patients undergoing radical prostatectomy. Further research is necessary using a much larger number of patients with a longer followup.