Comparative immunocytochemical assessment of isolated carcinoma cells in lymph nodes and bone marrow of patients with clinically localized prostate cancer

After radical prostatectomy for clinically localized prostate cancer, bioch emical progression is seen in up to 40% of the patients due to persistent l ocal and/or systemic remnants. Isolated disseminated carcinoma cells, undet ectable by current staging methods, are of special interest as potential pr ecursors of subsequent overt metastases. In the present study, immunohistoc hemistry (IHC) was pet-formed to evaluate simultaneously the frequency of o ccult carcinoma cells in both lymph nodes (LNs) and bone marrow (BM) obtain ed from the iliac crests of 45 prostate cancer patients with untreated stag e T1-3 pN(0) M-0 prostatic carcinoma. IHC using monoclonal antibodies (MAbs ) against epithelial cytokeratins was performed on 521 paraffin-embedded LN s histopathologically classified as tumorfree (pN(0)), as well as on BM cyt ospin preparations. To confirm the prostatic origin of positive cells in LN s, additional IHCs for prostate-specific antigen (PSA) and epithelial glyco proteins were performed, In total, isolated tumor cells in LNs and/or BM we re detected in 17 of the 45 patients. Parameters such as tumor stage, grade and volume of the primary tumor as well as blood serum PSA levels could no t detect patients harboring disseminated single tumor cells in LNs or BM. F ollowing a median observation time of 24.9 months, no significant correlati on between IHC positivity and PSA progression as a measure of early relapse was observed. Although the overall incidence of occult tumor cell spread c orresponds to similar incidence of relapses after radical prostatectomy as reported by others, the fate of these cells needs to be evaluated in longer follow-up studies. Int. J. Cancer(Pred. Oncol.) 84: 145-149, 1999. (C) 199 9 Wiley-Liss, Inc.