Adenocarcinoma of the Prostate Involving 2 Cell Types (Prostate Specific Antigen Producing and Carcinoembryonic Antigen Producing) with Selective Metastatic Spread

Of 3 patients with clinically localized adenocarcinoma of the prostate 2 were treated by radical prostatectomy and 1 was treated with radiation therapy. Serum prostate specific antigen (PSA) values were elevated before therapy. After treatment the PSA levels were decreased to zero. All 3 patients later had evidence of metastatic tumor spread to the liver with elevation of serum carcinoembryonic antigen but not PSA. Immunohistochemical staining of the 2 primary tumors from the prostatectomy specimens identified 2 cell clones, one immunoreactive to PSA and prostatic acid phosphatase (PAP) and nonimmunoreactive to carcinoembryonic antigen, and the other immunoreactive to carcinoembryonic antigen but not PSA or PAP. Biopsy of a hepatic metastasis in 2 patients confirmed anaplastic carcinoma of the carcinoembryonic antigen-producing cell type. Immunohistochemical staining of a lymph node metastasis identified the PSA-producing cell type only. Such results suggest selective metastatic spread of each cell type to its own organ tropic site. Occasional carcinoembryonic antigen-producing prostate cancers may metastasize to the liver. Serum carcinoembryonic antigen measurements occasionally may be useful in the management of certain prostate adenocarcinoma patients.