Objectives: To evaluate the prognostic significance of reverse transcriptase polymerase chain reaction (RT PCR) detection of prostate-specific antigen (PSA) mRNA in relation to survival in patients with metastatic androgen-independent prostatic carcinoma (AIPC).
Methods: Peripheral blood from 122 men (64 from Memorial Sloan-Kettering Cancer Center [MSKCC] and 58 from the Dana Farber Cancer Institute [DFCI]) with metastatic (Stage D2) AIPC was analyzed for PSA mRNA using RT PCR. Forty-one controls without prostatic carcinoma were also evaluated.
Results: RT PCR positivity for PSA mRNA was present in 24 of the 64 (38%) patients seen at MSKCC and in 26 of the 58 (45%) patients followed at DFCI. All control individuals were PSA PCR negative. There was a significant correlation between RT PCR positivity and decreased survival in each of the Memorial and Dana Farber population (P = 0.028 and 0.039, respectively). Serum PSA (at time of blood collection for PCR) was not predictive of survival as a continuous variable in the MSKCC [P = 0.31] and the DFCI (P = 0.09) groups. RT PCR for PSA mRNA was found to be independent from and superior to serum PSA in predicting survival in both the MSKCC and DFCI populations (P = 0.048 and P = 0.027, respectively).
Conclusions: The detection of PSA mRNA in the peripheral blood by RT PCR is a predictor of survival in patients with metastatic AIPC, and PCR is superior to a single serum PSA measurement. Further studies are needed to test the value of this factor in comparison to and coupled with other prognostic parameters.