The medical records of 217 prostate cancer patients and 1,080 controls were compared. Impotence, urinary retention, frequency, nocturia, haematuria, weight loss and abnormal rectal examinations were found to be predictive of prostate cancer.
Lead researcher Dr William Hamilton, GP and researcher at Bristol University, said: 'For patients who present with these symptoms, I would recommend PSA testing.'
Some of these factors are known symptoms, but impotence was a surprise finding. It is considered an adverse effect of prostate biopsy, rather than a symptom of prostate cancer. Compared with a background risk of 0.35 per cent, impotence was associated with a 3 per cent risk of developing prostate cancer.
Dr Hamilton suggested GPs carry out a rectal examination on patients with impotence.
Any signs of irregularity should then prompt referral for a PSA test.