Molecular and immunohistochemical staging of men with seminal vesicle invasion and negative pelvic lymph nodes at radical prostatectomy

BACKGROUND. Patients with seminal vesicle invasion (SVI) at radical retropu bic prostatectomy (RRP) have a poor prognosis. Routine microscopic examinat ion of pelvic lymph nodes (LNs) can miss small metastases and, thereby, con fuse tumor staging and clinical decision-making. The authors used immunohis tochemical and molecular methods to examine archival paraffin-embedded LNs of men who had undergone RRP for clinically localized prostate carcinoma an d who had tumors demonstrating SVI and negative LNs at surgery. METHODS. Between June 1982 and June 1997, 2151 consecutive men underwent RR P for clinically localized prostate carcinoma. Of these, 109 (5.1%) tumors had SVI with negative LNs. The actuarial likelihood of having a tumor that was undetectable by testing prostate-specific antigen (PSA) 5 and 10 years after surgery was 45% and 29%, respectively, for men with isolated SVI. Arc hival LN specimens were available for 102 men who had isolated SVI. Reverse transcription polymerase chain reaction (RT-PCR) was performed for PSA and prostate-specific membrane antigen (PSMA). All specimens were examined con currently by immunohistochemistry (IHC). RESULTS, Careful reevaluation of pelvic LNs demonstrated metastases in 9 (8 .8%) men originally classified as metastasis-free. Reevaluation by hematoxy lin and eosin (H&E) staining identified three previously unrecognized cases of LN metastases. IHC identified six cases, three of which were missed by H&E. RT-PCR identified four cases, three of which were not revealed by othe r methods. CONCLUSIONS. The poor prognosis of patients with SVI does not seem due to o ccult LN metastases. The low yield of unsuspected foci of prostate carcinom a in the LNs of men with SVI and negative LNs by routine staging does not j ustify IHC or molecular examination to find occult carcinoma. Cancer 2000;8 9:2577-86, (C) 2000 American Cancer Society.