The value of digital rectal examination as a predictor of prostate cancer diagnosis among United States Veterans referred for prostate biopsy

Background: As digital rectal examination (DRE) remains an essential part of a routine physical examination, it is important to understand its diagnostic value in different circumstances. Aim: To quantify sensitivity, specificity and predictive value of DRE as a predictor of biopsy-confirmed prostate cancer in the US Veteran population. Methods: The study group included 628 consecutive patients who underwent transrectal biopsy for suspected prostate cancer due to abnormal digital examination of the prostate, elevated serum prostate specific antigen (PSA) or both. The DRE results reported in this study are documented during physical examinations that were performed after referral for biopsy. The relation between DRE results and positive biopsy was examined while taking into consideration demographic and clinical patient characteristics. Results: Among men with normal PSA the adjusted odds ratio (OR) reflecting the association between abnormal DRE and positive prostate biopsy was 0.53 with a 95% confidence interval (CI) from 0.27 to 1.06. In the presence of a moderately elevated (4.1–10 ng/mL) PSA, the OR was 1.07 (0.72–1.60). When serum PSA exceeded 10 ng/mL, the OR was 2.15 (1.12–4.43). The positive predictive value of an abnormal DRE varied widely from as high as 81% to as low as 14% depending on the other patient characteristics. Discussion: These results indicate that DRE results are most informative when evaluated in conjunction with other clinical and demographic information.