Validation of dominant and secondary sequence utilization in PI-RADS v2 for classifying prostatic lesions

INTRODUCTION

To assess the secondary sequence rule in The Prostate Imaging Reporting Data System (PI-RADS) version 2 by comparing the detection of Grade group 1+ (GG1+) and 2+ (GG2+) cancers in PI-RADS 3, an upgraded PI-RADS 4, and true (non-upgraded) PI-RADS 4 targets.

MATERIALS AND METHODS

We analyzed a total of 589 lesions scored as PI-RADS 3 or 4 obtained from 434 men who underwent mpMRI-US fusion biopsy from September 2015 to November 2017 for evaluation of GG1+ and GG2+ prostate cancer. PI-RADS 4 lesions were differentiated into those that were 'upgraded' to PI-RADS 4 based on the secondary sequence and those that were 'true' PI-RADS 4 based on the dominant sequence.

RESULTS

The odds of detecting a GG2+ cancer was significantly higher for an upgraded 4 (peripheral zone (PZ): OR 5.06, 95%CI 2.04-12.54, p < 0.001, transitional zone (TZ): OR 3.08, 95%CI 1.04-9.08, p = 0.042) and true 4 (PZ: OR 5.82, 95%CI 3.10-10.94, p < 0.0001, TZ: OR 2.43, 95%CI 1.14-5.18, p = 0.022) lesions compared to PI-RADS 3 lesions. Additionally, we found no difference in the odds of detecting a GG2+ prostate cancer between a true PI-RADS 4 (OR 1.15, 95%CI 0.49-2.71 p = 0.746) and upgraded 4 (referent) in the PZ. Similar non-significance was noted between true 4 (OR 0.79, 95%CI 0.26-2.38 p = 0.674) and upgraded 4 lesions in the TZ for detection of GG2+ cancers.

CONCLUSIONS

Upgraded PI-RADS 4 and true 4 targets have a higher odds of detecting GG1+ and GG2+ compared to PI-RADS 3 in the PZ and TZ. Our findings validate the revised scoring system for PI-RADS.

Entering an era of radiogenomics in prostate cancer risk stratification

Radiogenomics is a field that amalgamates data from genomics and imaging techniques in order to derive clinically meaningful trends. In this article, we discuss the importance of prostate cancer risk classification and how data derived from genomic testing and multi-parametric magnetic resonance imaging (mpMRI) can be integrated into clinical decision-making processes with a focus on active surveillance (AS). Finally, we describe an ongoing prospective trial (Miami MAST trial) which incorporates imaging (mpMRI) and radiomics data in patients who are on AS for prostate cancer.

The Influence of Ethnic Heterogeneity on Prostate Cancer Mortality After Radical Prostatectomy in Hispanic or Latino Men: A Population-based Analysis

OBJECTIVE

To determine if recently found disparities in prostate cancer-specific mortality (PCSM) among Mexican and Puerto Rican men remained true in patients undergoing radical prostatectomy (RP), where the true grade and extent of cancer are known and can be accounted for.

MATERIALS AND METHODS

Men diagnosed with localized-regional prostate cancer who had undergone RP as primary treatment were identified (N = 180,794). Patients were divided into the following racial and ethnic groups: non-Hispanic white (NHW) (n = 135,358), non-Hispanic black (NHB) (n = 21,882), Hispanic or Latino (n = 15,559), and Asian American or Pacific Islander (n = 7995). Hispanic or Latino men were further categorized into the following subgroups: Mexican (n = 3323) and South or Central American, excluding Brazilian (n = 1296), Puerto Rican (n = 409), and Cuban (n = 218). A multivariable analysis was conducted using competing risk regression in the prediction of PCSM.

RESULTS

This analysis revealed hidden disparities in surgical outcomes for prostate cancer. In the multivariable analysis, Hispanic or Latino men (hazard ratio [HR] = 0.88, P = .207) did not show a significant difference in PCSM compared with NHW men. When breaking Hispanic or Latino men into their country of origin or ancestry, Puerto Rican men were found to have significantly worse PCSM than NHW men (HR = 2.55, P = .004) and NHB men (HR = 2.33, P = .016).

CONCLUSION

Our findings reveal higher rates of PCSM for Puerto Rican men after RP than for both NHW and NHB men. At a minimum, these findings need further validation and should be considered in the screening and management of these men.

Imaging for the selection and monitoring of men on active surveillance for prostate cancer

Traditional prostate imaging is fairly limited, and only a few imaging modalities have been used for this purpose. Until today, grey scale ultrasound was the most widely used method for the characterization of the prostatic gland, however its limitations for prostate cancer (PCa) detection are well known and hence ultrasound is primarily used to localize the prostate and facilitate template prostate biopsies. In the past decade, multiparametric magnetic resonance imaging (mpMRI) of the prostate has emerged as a promising tool for the detection of PCa. Evidence has shown the value of mpMRI in the active surveillance (AS) population, given its ability to detect more aggressive disease, with data building up and supporting its use for the selection of patients suitable for surveillance. Additionally, mpMRI targeted biopsies have shown an improved detection rate of aggressive PCa when compared to regular transrectal ultrasound (TRUS) guided biopsies. Current data supports the use of mpMRI in patients considered for AS for reclassification purposes; with a negative mpMRI indicating a decreased risk of reclassification. However, a percentage of patients with negative imaging or low suspicion lesions can experience reclassification, highlighting the importance of repeat confirmatory biopsy regardless of mpMRI findings. At present, no robust data is available to recommend the substitution of regular biopsies with mpMRI in the follow-up of patients on AS and efforts are being made to determine the role of integrating genomic markers with imaging with the objective of minimizing the need of biopsies during the follow up period.