A newly published study has suggested that the risk calculator based on data from the European Randomized Study of Screening for Prostate Cancer (ERSPC-RC) may be a better predictor of risk for prostate cancer in Canadians that the risk calculator based on the US-based Prostate Cancer Prevention Trial (PCPT-RC).
This new paper by Trottier et al. was based on a careful analysis of data from 982 consecutive patients for whom all the appropriate data were available and who were prospectively evaluated before biopsy for risk of prostate cancer. All patients were evaluated at a single Toronto-based institution, which could, perhaps, represent a geographically limiting element of the trial, although Toronto may well be the best possible example of the broad ethnicity of the Canadian population as a whole.
The study showed that:
- Prostate cancer was detected in 46 percent of patients.
- High-grade prostate cancer (i.e., a Gleason grade ≥ 4) was detected in 23 percent of patients.
- The average (median) PSA level of men diagnosed with prostate cancer was 6.02 ng/ml.
- A nodule identifiable on transrectal ultrasonography, the prostate volume, and the patient’s PSA level were the most important predictors of prostate cancer overall and of high-grade prostate cancer.
- The ERSPC-RC (AUC = 0.71) outperformed the PCPT-RC (AUC = 0.63) and PSA alone (AUC = 0.55) as a tool for the prediction of prostate cancer (P < 0.001).
- The PCPT-RC was better calibrated than the ERSPC-RC in the higher risk range (40 to 100 percent).
- Conversely, the ERSPC-RC was better calibrated and avoided more biopsies in the lower risk range (0 to 30 percent).
The ERSPC-RC has never been validated in any North American patient cohort (whereas the PCPT-RC has, multiple times). This study suggests that validation of the ERSPC-RC in a Canadian patient cohort may be a useful exercise to further explore the appropriateness of this risk calculator as compared to the PCPT-RC in Canadian patients at risk for prostate cancer.