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Abnormal digital rectal examinations require urgent investigation for cancer, but the test has flaws, research says

Digital rectal examinations may not be an accurate diagnostic tool for cancer in primary care

Digital rectal examinations may not be an accurate diagnostic tool for cancer in primary care

People with an abnormal digital rectal examination (DRE) should be recommended for urgent referral for suspected prostate cancer, a review suggests. This finding is in line with National Institute for Health and Care Excellence (NICE) guidelines, which recommend performing DRE on patients with urinary symptoms and urgently referring if the prostate feels malignant. However, the study casts doubt on the use of DRE as a diagnostic tool in primary care due to its low sensitivity and negative predictive value.

Patients with an abnormal digital rectal examination should have an urgent referral to investigate for cancer. Picture: Alamy

The review included four studies from 2015, with data from a total sample population of 3,225 patients aged 40-89 years. The primary outcomes observed were the sensitivity and specificity of the examination and secondary outcomes were cost-effectiveness and adverse effects.

Despite the overall finding, the authors say there are issues to be considered that may suggest the test is superfluous and, in some cases, may even delay diagnosis. The sensitivity of the test was low, with the finding that over a quarter of patients subsequently diagnosed with prostate cancer did not have an abnormal DRE. Equally, the predictive value was poor and symptomatic patients who presented to primary care and had a normal prostate examination still had a risk of cancer of 15.8%, considerably above the 3% risk threshold proposed by NICE.

The review concludes that a patient's risk of prostate cancer based on symptoms alone would warrant urgent referral even if the DRE feels normal.

There were 47,151 new cases of prostate cancer in the UK in 2015 and 11,631 deaths from the disease in 2016, according to Cancer Research UK. While survival has increased, more than doubling over the past four decades, the disease remains a significant cause of cancer morbidity and mortality.

Jones D, Friend C, Dreher A et al (2018) The diagnostic test accuracy of rectal examination for prostate cancer diagnosis in symptomatic patients: a systematic review. BMC Family Practice. 19, 79, 1-6. doi: 10.1186/s12875-018-0765-y

Dion Smyth is a lecturer-practitioner in cancer and palliative care at Birmingham City University

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