Optimizing detection of clinically significant prostate cancer through nomograms incorporating mri, clinical features, and advanced serum biomarkers in biopsy naïve men

PURPOSE

To develop nomograms that predict the detection of clinically significant prostate cancer (csPCa, defined as ≥GG2 [Grade Group 2]) at diagnostic biopsy based on multiparametric prostate MRI (mpMRI), serum biomarkers, and patient clinicodemographic features.

MATERIALS AND METHODS

Nomograms were developed from a cohort of biopsy-naïve men presenting to our 11-hospital system with prostate specific antigen (PSA) of 2-20 ng/mL who underwent pre-biopsy mpMRI from March 2018-June 2021 (n = 1494). The outcomes were the presence of csPCa and high-grade prostate cancer (defined as ≥GG3 prostate cancer). Using significant variables on multivariable logistic regression, individual nomograms were developed for men with total PSA, % free PSA, or prostate health index (PHI) when available. The nomograms were both internally validated and evaluated in an independent cohort of 366 men presenting to our hospital system from July 2021-February 2022.

RESULTS

1031 of 1494 men (69%) underwent biopsy after initial evaluation with mpMRI, 493 (47.8%) of whom were found to have ≥GG2 PCa, and 271 (26.3%) were found to have ≥GG3 PCa. Age, race, highest PIRADS score, prostate health index when available, % free PSA when available, and PSA density were significant predictors of ≥GG2 and ≥GG3 PCa on multivariable analysis and were used for nomogram generation. Accuracy of nomograms in both the training cohort and independent cohort were high, with areas under the curves (AUC) of ≥0.885 in the training cohort and ≥0.896 in the independent validation cohort. In our independent validation cohort, our model for ≥GG2 prostate cancer with PHI saved 39.1% of biopsies (143/366) while only missing 0.8% of csPCa (1/124) with a biopsy threshold of 20% probability of csPCa.

CONCLUSIONS

Here we developed nomograms combining serum testing and mpMRI to help clinicians risk stratify patients with elevated PSA of 2-20 ng/mL who are being considered for biopsy. Our nomograms are available at https://rossnm1.shinyapps.io/MynMRIskCalculator/ to aid with biopsy decisions.

Utilization of genetic testing in men with advanced prostate cancer

BACKGROUND

Genetic evaluation of men with advanced prostate cancer is recognized as imperative both to guide treatment decisions and to trigger cascade genetic testing of family members. Here we investigate utilization patterns of genetic testing among a contemporary cohort of men with advanced prostate cancer at our institution.

METHODS

We queried the Northwestern Electronic Data Warehouse from January 2021 to present for all men diagnosed with National Comprehensive Cancer Network high-risk/very high-risk, regional, or metastatic prostate cancer. Patients were excluded from analyses if treated at an outside institution and/or presented for a second opinion evaluation. Statistics were performed using t-test, Chi-squared test, and univariable and multivariable logistic regression with significance defined as p < 0.05.

RESULTS

Atotal of 320 men (52.5%) had local/regional disease and 290 (47.5%) had metastatic disease, 53 (18.3%) of whom had castrate resistant prostate cancer. Rates of germline genetic testing rate were low in patients with localized disease (9.4%) and metastatic disease (34.1%). Only 19 (35.8%) men diagnosed with metastatic castrate resistant prostate cancer underwent germline genetic evaluation. Germline testing was most frequently discussed or ordered by medical oncologists (52%) followed by urologists (20%). Men who underwent germline testing were younger (p < 0.001), more likely to have Medicaid or private insurance (p = 0.002), and more likely to have metastatic disease (p < 0.001). There were no statistically significant differences in baseline PSA, ethnicity, race, or castration sensitivity status. Age (odds ratio [OR]: 0.94, 95% confidence interval [CI]: 0.91-0.97, p < 0.001) and metastatic disease (OR: 5.71, 95% CI: 3.63-9.22, p < 0.001) were significant independent predictors of genetic testing on multivariable logistic regression.

CONCLUSIONS

Here we report that utilization of genetic testing is associated with metastatic disease and inversely associated with age. Overall, utilization rates of genetic testing remain low in all patient groups, including in the metastatic castrate resistant setting, where genetic testing can identify patients with homologous recombination repair deficiency who may benefit from use of targeted therapeutics such as PARP inhibitors. Genetic testing in men with aggressive prostate cancer is critical and barriers to routine implementation of testing require further study to develop strategies to improve utilization rates.