Identification of Clinically Significant Prostate Cancer by Combined PCA3 and AMACR mRNA Detection in Urine Samples

Abstract

Purpose

Preclinical evaluation of PCA3 and AMACR transcript simultaneous detection in urine to diagnose clinical significant prostate cancer (prostate cancer with Gleason score ≥7) in a Russian cohort.

Patients and Methods

We analyzed urine samples of patients with a total serum PSA ≥2 ng/mL: 31 men with prostate cancer scheduled for radical prostatectomy, 128 men scheduled for first diagnostic biopsy (prebiopsy cohort). PCA3, AMACR, PSA and GPI transcripts were detected by multiplex reverse transcription quantitative polymerase chain reaction, and the results were used for scores for calculation and statistical analysis.

Results

There was no significant difference between clinically significant and nonsignificant prostate cancer PCA3 scores. However, there was a significant difference in the AMACR score (patients scheduled for radical prostatectomy p=0.0088, prebiopsy cohort p=0.029). We estimated AUCs, optimal cutoffs, sensitivities and specificities for PCa and csPCa detection in the prebiopsy cohort by tPSA, PCA3 score, PCPT Risk Calculator and classification models based on tPSA, PCA3 score and AMACR score. In the clinically significant prostate cancer ROC analysis, the PCA3 score AUC was 0.632 (95%CI: 0.511–0.752), the AMACR score AUC was 0.711 (95%CI: 0.617–0.806) and AUC of classification model based on the PCA3 score, the AMACR score and total PSA was 0.72 (95%CI: 0.58–0.83). In addition, the correlation of the AMACR score with the ratio of total RNA and RNA of prostate cells in urine was shown (tau=0.347, p=6.542e–09). Significant amounts of nonprostate RNA in urine may be a limitation for the AMACR score use.

Conclusion

The AMACR score is a good predictor of clinically significant prostate cancer. Significant amounts of nonprostate RNA in urine may be a limitation for the AMACR score use. Evaluation of the AMACR score and classification models based on it for clinically significant prostate cancer detection with larger samples and a follow-up analysis is promising.

Keywords:

• prostatic neoplasms
• early diagnosis
• neoplasm grading
• alpha-methylacyl-CoA racemase
• RNA

Acknowledgments

The authors thank the Ministry of Education and Science of Russian Federation and the Russian Foundation for Basic Research for their support.

Abbreviations

PSA, prostate specific antigen; RT-qPCR, reverse transcription quantitative polymerase chain reaction; csPCa, clinically significant prostate cancer; GS, Gleason score; AUC, area under the ROC curve; non-csPCa, clinically nonsignificant prostate cancer; PCa, prostate cancer; BPH, benign prostate hyperplasia; RPE, radical prostatectomy; qPCR, quantitative polymerase chain reaction; tPSA, total PSA; PCPTRC, Prostate Cancer Prevention Trial Risk Calculator; ROC curve, Receiver operating characteristic curve.

Ethics Approval and Informed Consent

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Declaration of Helsinki and its later amendments. Harmonized protocol was approved September 14, 2017 by the local ethics committee of The First Moscow State Medical University named after I.M. Sechenov (Sechenov University, Moscow, Russia) followed by all centers. Informed consent was obtained from all participants included in the study. Patient information was anonymized and remained confidential. Samples were collected between September 15, 2017 and February 27, 2018.

Disclosure

Elena S Kotova reports grants from Ministry of Education and Science of Russian Federation, grants from Russian Foundation for Basic Research, grants from Russian Foundation for Basic Research, during the conduct of the study. Yulia A Savochkina is an employee of Lytech Ltd. Alexander O Vasilyev reports grants from Russian Foundation for Basic Research according, during the conduct of the study. Elena A Prilepskay reports grants from Russian Foundation for Basic Research, during the conduct of the study. Konstantin A Babalyan reports grants from Ministry of Education and Science of Russian Federation, during the conduct of the study. Alexander Govorov reports grants from Russian Foundation for Basic Research, during the conduct of the study. Elena S Kostryukova reports grants from Ministry of Education and Science of Russian Federation, during the conduct of the study. Elena I Sharova reports grants from Ministry of Education and Science of Russian Federation, grants from Russian Foundation for Basic Research, during the conduct of the study. The authors reports no other potential conflicts of interest in this work.

Additional information

Funding

Primers and probes design, plasmid construction, reverse transcription and multiplex qPCR condition optimization was supported by the Ministry of Education and Science of Russian Federation (grant no. 14.607.21.0068, Sep 23, 2014, unique ID RFMEFI60714×0068). Prebiopsy cohort urine samples analysis, histopathological examination of biopsy material, statistical analysis of obtained data funded by the Russian Foundation for Basic Research according to the research project no. 17-29-06076 (grant no. 17-29-06076\18, Dec 05, 2018). Urine analysis and histopathological examination of surgical material of patients scheduled for radical prostatectomy, statistical analysis of obtained data funded by the Russian Foundation for Basic Research according to the research project no. 18-315-00363 (grant no. 18-315-00363\19, Mar 07, 2019).