Background: Patients with seminal vesicle invasion (SVI) at radical retropubic prostatectomy (RRP) have a poor prognosis. Routine microscopic examination of pelvic lymph nodes (LNs) can miss small metastases and, thereby, confuse tumor staging and clinical decision-making. The authors used immunohistochemical and molecular methods to examine archival paraffin-embedded LNs of men who had undergone RRP for clinically localized prostate carcinoma and who had tumors demonstrating SVI and negative LNs at surgery.
Methods: Between June 1982 and June 1997, 2151 consecutive men underwent RRP 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. Archival 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 concurrently by immunohistochemistry (IHC).
Results: Careful reevaluation of pelvic LNs demonstrated metastases in 9 (8.8%) men originally classified as metastasis-free. Reevaluation by hematoxylin 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 other methods.
Conclusions: The poor prognosis of patients with SVI does not seem due to occult LN metastases. The low yield of unsuspected foci of prostate carcinoma in the LNs of men with SVI and negative LNs by routine staging does not justify IHC or molecular examination to find occult carcinoma.
Copyright 2000 American Cancer Society.