The value of combined detection of PCA3 mRNA and PSA mRNA in peripheral blood of patients with prostate cancer

Abstract

Objective To evaluate the application value of combined detection of PCA3 and PSA mRNA in peripheral blood of patients with prostate cancer(PCa) for evaluation of mien)metastasis. Methods PCA3 and PSA mRNA were detected by duplex real time quantitative RT-PCR in a total of 49 PCa and 71 benign protatic hyperplasia (BPH) patients' peripheral blood. The diagnostic value was analyzed by receiver operative characteristic(ROC) curve. Results The levels of PCA3 mRNA in PCa patients were significantly higher than those in BPH patients [2 362( <30-7 421 ) copies/ml vs <30 copies/M, Z = -6. 66, P < 0. 01 ], and the same to PSA mRNA [3 425 ( 908-36 639 ) copies/ml vs < 200 copies/ml, Z = - 6. 40, P<0. 01 ]. The positive rate of PCA3 and PSA mRNA in peripheral blood was positively correlated with clinical stage[clinical stage B: 30.0% (3/10), C: 60.0% (9/15) and 86.7% (13/15), D: 91.7% (22/24) and 91.7% (22/24) ,Chi-square = 13. 534 and 16. 541, P <0. 01, respectively]. Meanwhile, the positive rate of PCA3 mRNA and PSA mRNA was also increased with the increase of Gleason score[ Gleason score of 2 to 4 : 20.0% (1/5) and 40. 0% (2/5) ;5 to 7 : 66.7% (12/18) and 72. 2% ( 13/18 ) ;8 to 10 : 84. 6% (22/26) and 92.3% ( 24/26 ) ;Chi-square = 8. 895 and 8. 015, P < 0. 05, respectively ]. ROC analysis showed that the sensitivities for PCA3 and PSA mRNA were 69. 4% (34/49) and 81.7% (40/49) and the specificities was 90. 1% (64/71) and 77.5% (55/71), respectively, when the cut-off value was 846 copies/ml for PCA3 mRNA and 280 copies/ml for PSA mRNA. Meanwhile, the sensitivity can reach to 85.7% (42/49) when the detection of PCA3 and PSA mRNA were combined. However, the specificity was decreased to 76. 1% (54/71). For the diagnosis of PCa micrometastasis, the sensitivity and specificity for PCA3 mRNA was 90.9% (20/22) and 84.7% (11/13), respectively. Conclusions PCA3 and PSA mRNA in peripheral blood are useful markers for PCa diagnosis. Simultaneous detection for PCA3 and PSA mRNA is more helpful for PCa diagnosis. Meanwhile, detection of PCA3 mRNA is a useful marker for diagnosing PCa micrometastasis. Key words: Prostatic neoplasms; Neoplasms metastasis; Antigens, neoplasm; Prostate-specific antigen; Reverse transcriptase polymerase chain reaction