Prostate cancer diagnostics test
The prostate cancer diagnostic test is an examination measure to estimate the likelihood of the positive biopsy and to aid in the decision for biopsy. In this test two scores are determined, one of which evaluates the possibility of the positive biopsy, while the other estimates the risk of clinically significant cancer. Cancer is considered clinically significant if the Gleason score is equal to or higher than 7. The test can be performed using urine samples collected with or without DRE (prostate massage). A biopsy is required to confirm the diagnosis of prostate cancer.
Implementing the prostate cancer diagnostic test the quantities of prostate cancer-specific biomarkers are determined in the first catch urine specimens. Urine specimens are collected using special tubes with a funnel that ensures that the first 10 ml of the urine are collected. Once in the tube, the urine is immediately mixed with the stabilizing medium that protects the nucleic acids from degradation. The stabilized urine specimens are shipped to Diagnolita’s laboratory for analysis.
Prostate cancer
Prostate cancer is mostly diagnosed in older men. For a prolonged period of time after the first appearance of cancer cells in the prostate no disease symptoms are manifested. Therefore, this disease is often diagnosed in the late stages when the patients start expressing symptoms similar to those of urinary tract infection or benign prostatic hyperplasia. When prostate cancer spreads to other organs and tissues such symptoms as pains in the pelvic area, in the hips, and in the back, as well as blood in the urine appear.
Several biochemical, molecular, physical and radiological methods are used to diagnose prostate cancer. However, the final approval of the diagnosis is based on the histological examination of the prostate tissue -biopsy. The main prostate cancer diagnostic test in the current clinical practice is the concentration of the PSA in the blood serum.
In the case of elevated concentration of PSA in blood serum biopsy (an invasive procedure) is assigned. The tissue is collected from several locations in the prostate. The biopsy may be performed transrectally or through the perineum. The examination of the tissue confirms or denies the cancer diagnosis. In the case of cancer, the histological structure of the cancerous tissue is determined.
The PSA protein is specific for the prostate but not specific for the prostate cancer. Increase in the concentration of PSA may be caused not only by cancer but also by several other conditions – benign prostatic hyperplasia, prostatitis, high grade prostatic intraepithelial neoplasia (HPIN). Therefore, quite often the biopsies do not confirm the cancer diagnosis. Biopsies increase the risk of complications caused by the invasive test. Diagnolita‘s molecular urine test allows avoiding prostate biopsies in case of low risk of cancer.
Features of Diagnolita’s Prostate Cancer Test
Non-invasive – patient‘s urine specimen is used for analysis
Versatile– can be performed with or without DRE
Cost efficient – one test estimates both the likelihood of cancer and the risk of high-grade cancer
Sensitive and specific – based on detection of well-defined molecular biomarkers
Diagnolita’s Non-invasive Prostate Cancer Diagnostic Test
Diagnolita’s prostate cancer test is recommended for men when the PSA concentration in their serum is between 2 ng/ml and 10 ng/ml and prostate cancer is suspected. Two prostate cancer-specific RNA biomarkers are quantified in patients‘ urine using RT-qPCR method. The data is combined with clinical parameters to predict both the presence of prostate cancer and the likelihood of the high-grade prostate cancer on biopsy.
Diagnolita‘s test biomarkers
PCA3 –prostate cancer antigen 3, the gene of prostate-specific long noncoding RNA, which has high expression levels in 95% of prostate cancer cases.
TMPRSS2:ERG (TE) – gene fusion between the androgen-regulated gene TMPRSS2 and transcription factor ERG is present in about 40-80% of prostate cancer cases, can be found in the case of HGPIN.
Features of Diagnolita’s Prostate Cancer Test
Non-invasive – patient‘s urine specimen is used for analysis
Versatile– can be performed with or without DRE
Cost efficient – one test estimates both the likelihood of cancer and the risk of high-grade cancer
Sensitive and specific – based on detection of well-defined molecular biomarkers
Examples of Diagnolita’s test results
Results of the Study of Clinical Efficiency of the Test
The clinical efficiency of the Diagnolita‘s prostate cancer diagnostic test has been proved in a multicenter study with a large cohort of patients.
| Number of patients (PSA 2-10 ng/ml) | Urine collected w/o DRE | Urine collected after DRE |
|---|---|---|
| Total number of patients | 295 | 303 |
| Patients with positive biopsy | 146 | 153 |
| Patients with negative biopsy | 149 | 150 |
The diagnostic parameters of Diagnolita’s test performed both with or without DRE outperform the diagnostic parameters of the PSA test. At 90% sensitivity, the specificity of Diagnolita’s test for high-grade prostate cancer is 43% versus 9% of the PSA test.
The diagnostic parameters of Diagnolita’s test are comparable to similar urine molecular diagnostic tests
| Prognosis | DRE | AUC | Sensitivity | Specificity | NPV | PPV | Avoided biopsies |
|---|---|---|---|---|---|---|---|
| LIKELIHOOD OF PROSTATE CANCER (Positive biopsy) | NO | 71% | 90% | 33% | 78% | 57% | 21% |
| Yes | 78% | 90% | 43% | 81% | 62% | 26% | |
| LIKELIHOOD OF HIGH GRADE (Gleason >= 7, ISUP >= 2) PROSTATE CANCER | NO | 74% | 90% | 43% | 93% | 33% | 35% |
| Yes | 79% | 89% | 55% | 94% | 38% | 45% |