# Clinical Relevance of Digital Rectal Examination in Men With Low and Very Low Prostate-Specific Antigen (PSA): Reassessing Its Diagnostic Value in the MRI Era and in Light of Modern Guidelines

## TL;DR

This study finds that while digital rectal exams (DRE) are not a primary screening tool for prostate cancer, they still help detect some clinically significant cases in men with low PSA levels.

## Contribution

The study reassesses the role of DRE in low PSA patients in the MRI era, showing its continued relevance in detecting clinically significant prostate cancer.

## Key findings

- DRE detected 16.8% of prostate cancers in low PSA patients that would have been missed otherwise.
- Among DRE-positive patients with PSA < 4 ng/mL, 67.9% had prostate cancer and 35.7% had clinically significant tumors.
- DRE-associated cancer detection was more frequent in PSA < 3 ng/mL compared to 3-4 ng/mL.

## Abstract

Background/aim

Digital rectal examination (DRE) has declined in importance as a primary screening tool for prostate cancer (PCa), yet it remains relevant as a selective clinical assessment. This study aimed to evaluate the residual diagnostic value of DRE in men with low prostate-specific antigen levels (PSA < 4 ng/mL), who would otherwise not undergo further diagnostic evaluation, and to identify cases in which PCa was detected primarily on the basis of an abnormal DRE finding.

Patients and methods

We conducted a retrospective analysis of a prospectively maintained, single-center database comprising all consecutive MRI-ultrasound fusion-guided prostate biopsies performed between August 2014 and September 2024 at a university high-volume center (n = 1,300). Men were eligible if they presented with elevated PSA and/or a suspicious DRE, with abnormal findings confirmed by a second senior urologist. For the present analysis, all patients with PSA < 4 ng/mL (Group A, n = 114) were selected and further stratified into two subgroups: PSA 3-4 ng/mL (Group B, n = 57) and PSA < 3 ng/mL (Group C, n = 57). Primary endpoints were the detection of overall PCa and clinically significant PCa (csPCa; International Society of Urological Pathology (ISUP) grade group ≥ 2). In addition, we evaluated the proportion of tumors associated with a positive DRE.

Results

No significant differences were observed between the three subgroups in the detection rates of overall PCa (64/114 vs. 31/57 vs. 33/57; p = 0.85) or csPCa (29/64 vs. 15/57 vs. 14/57; p = 1.00). However, DRE-associated PCa detection was significantly more frequent in the PSA < 3 ng/mL subgroup than between 3 and 4 ng/mL (24.6% vs. 8.8%; p = 0.044), with no corresponding difference in DRE-detected csPCa (p = 0.32). Among all DRE-positive patients with PSA < 4 ng/mL, PCa and csPCa detection rates were 67.9% and 35.7%, respectively, without significant differences between PSA strata (both p = 0.63). Without DRE, 16.8% of PCas (19/114) would not have been detected, including 10 clinically significant tumors (8.8%). Histopathological analysis showed predominantly low-grade tumors (peak ISUP 1), with fewer csPCa cases.

Conclusion

In men with PSA < 4 ng/mL, the diagnostic yield of DRE was limited, yet a clearly abnormal DRE remained a meaningful indicator of PCa and identified a small but relevant proportion of clinically significant tumors that would have been missed by PSA- and MRI-driven pathways alone. While DRE no longer serves as a screening tool, our findings support its selective use in the diagnostic work-up, where suspicious palpatory findings continue to warrant further evaluation.