SENSITIVITY OF IMMUNOHISTOCHEMISTRY AND POLYMERASE CHAIN-REACTION IN DETECTING PROSTATE-CANCER CELLS IN BONE-MARROW

Occult micrometastases detected by immunohistochemistry have prognosti c significance in patients with localized breast cancer. To determine the usefulness of this technique and of polymerase chain reaction in d etecting occult prostate cancer, we evaluated the sensitivity and spec ificity of immunohistochemistry and polymerase chain reaction amplific ation of mRNA to detect prostate cancer cells in bone marrow samples. We used cells from an established prostate cancer cell line (LNCAP) mi xed with lymphocytes at various dilutions from 10(5) cancer cells in 1 0(6) lymphocytes to 1:10(6). Both techniques had a 100% specificity an d identified cancer cells at all dilutions. Polymerase chain reaction was more sensitive than immunohistochemistry at the lowest dilutions ( 10(-5) and 10(-6), p = 0.033). We have evaluated seven patients with p rostate cancer for micrometastases. Both of the patients with known me tastatic prostate cancer and one of the five patients with cinically l ocalized tumors had micrometastases. Detection of micrometastases may be useful in the staging of prostate cancer.