Is digital rectal examination still useful in prostate cancer diagnosis? NO!

Prostate cancer (PCa) screening is one of the most controversial topics in the urological literature. The World Health Organization (WHO) has stipulated that screening tests should have scientific evidence to demonstrate their effectiveness and that the overall benefits of screening should outweigh harms. Official guidelines on PCa screening are conflicting because of potential harms from overdiagnosis and overtreatment versus the benefits of improved morbidity and mortality from early diagnosis.

Recently (2017), the U.S. Preventive Services Task Force (USPSTF) issued an updated statement suggesting that men aged 55–69 years should be informed about the benefits and harms of prostate-specific antigen (PSA)-based screening, as this might be associated with a small survival benefit. However, the impact of the USPSTF recommendation on use of digital rectal examination (DRE) remains unstudied. ¹ Following USPSTF recommendation, the proportion of visits, in the United States, where DRE was performed in primary care, dramatically decreased from 16.0% to 5.8%. ²

Some studies indicate that an ‘abnormal’ DRE, in patients with a PSA level ⩽2 ng/mL, has a positive predictive value of 5%–30% and is associated with an increased risk of higher Gleason Score and is an indication for biopsy. ³

However, the current role of the DRE remains to be clarified, due to the high levels of between-study heterogeneity. Recently, the first systematic review to investigate the effectiveness of DRE for PCa screening in primary care was published. ⁴ The study included the review and meta-analysis of seven studies with 9241 patients who underwent both DRE and prostate biopsy. In the pooled analysis of the seven studies, DRE performed by primary-care clinicians generally had poor performance for PCa screening, and there was high heterogeneity across studies. Pooled sensitivity, specificity, positive predictive value and negative predictive value of the DRE performed by primary care clinicians was 0.51, 0.59, 0.41 and 0.64, respectively.

Many studies of DRE have flaws, resulting in ‘very low’ quality. There are various definitions for abnormal DRE and a lot of differences in training for primary care practitioners, in performing DRE, which could explain the between-study heterogeneity. A survey across Canadian medical schools revealed considerable differences in teaching methods and found that approximately one-half of graduating students had never performed a DRE during their clerkship training. ⁵ Moreover, there is a significant inter-examiner reliability between urologists in identifying a prostate finding as suspicious for cancer.

Some evidence suggests that the DRE may not significantly reduce mortality but instead may result in a high number of false-positives, leading to overdiagnosis and overtreatment of PCa. ⁶

Therefore, routine DRE in PCa screening does not meet the WHO criteria. Particularly, we do not recommend the routine use of DRE as a screening tool for PCa in primary care, unless it is proven effective in future studies. In addition, the role of the DRE will lose more significance since the increasing of two evidences: