A recent study looked at whether a rectal examination performed by family doctors is useful in screening for prostate cancer.
Current estimates state that over one million men receive a diagnosis of prostate cancer every year. The prostate is a small, walnut-sized organ sitting just below the bladder in men. It surrounds a part of the male urethra, which is the outflow tube from the bladder. It produces some of the fluid that is found in semen. As men age, they have an increasing risk of prostate cancer. Because it is one of the most common cancers in men, there are several screening programs for prostate cancer to make early diagnoses.
Most screening programs include a rectal examination by a physician. By placing their finger in the patient’s rectum, the doctor can feel the prostate gland through the rectal wall and check for changes in its shape or hardness that may indicate cancer. However, there has been some debate as to how useful rectal examinations are in screening for prostate cancer, particularly if they are performed by a non-specialist.
Researchers in Canada combined and analyzed data from published studies on the accuracy of digital rectal examination performed by family doctors. They recently published their findings in the Annals of Family Medicine.
Rectal examination by family doctors has low accuracy
The researchers made an extensive search of the published literature to find studies looking at rectal examinations by family doctors to screen for prostate cancer. Seven studies, including over 9,200 patients were eligible for their analysis. All of these patients had rectal examination and biopsies to check for prostate cancer.
The researchers combined the data from these studies to calculate the “sensitivity” and “specificity” of rectal examination performed by family doctors. Sensitivity and specificity are measures of the accuracy of a test in identifying true cases while avoiding false negatives (missed disease cases) and false positives (healthy subjects identified as disease cases). The combined analysis showed that the sensitivity and specificity of rectal examination by family doctors in identifying true prostate cancer cases is low.
Rectal examination not recommended for prostate cancer screening in primary care
This combined analysis suggests that the accuracy of rectal examination performed by family doctors as a screening test for prostate cancer is low. Furthermore, a survey of family doctors showed that only one-half of them feel confident in their ability to detect changes in the prostate by rectal examination.
On the basis of this analysis and a review of other available studies, the researchers do not recommend the routine use of rectal examination as a prostate cancer screening test in the primary care setting. This may avoid unnecessary further invasive tests, over-diagnosis, and the over-treatment of prostate cancer.
Written by Julie McShane, Medical Writer
Reference: Naji L, Randhawa H, Sohani, et al. Digital rectal examination for prostate cancer screening in primary care: a systematic review and meta-analysis. Annals of Family Medicine Vol 16, No. 2, March-April 2018.