Case-control prostate cancer screening studies should not exclude subjects with lower urinary tract symptoms

Prostate-specific antigen (PSA)/digital rectal exam (DRE) screening for prostate cancer has become standard medical practice; however, its effectiveness in terms of reducing prostate cancer mortality remains undetermined. Case-control screening studies may help determine screening efficacy, though the proper disposition of symptomatic subjects is unclear. This paper presents a prostate cancer-specific methodological modification for analyzing symptomatic case-control screening subjects.

Prostate cancer detection studies and case-control studies of PSA/DRE screening were reviewed, and the results for symptomatic and asymptomatic subjects were compared.

Most PSA/DRE detection studies have found that the prostate cancer detection rate among symptomatic patients is the same as or lower than that among asymptomatic patients. Lower urinary tract symptoms (LUTS), often referred to as early prostate cancer symptoms, occur more often in benign prostatic hyperplasia (BPH), a more commonly diagnosed, nonmalignant disease. Screened symptomatic subjects are usually removed from the "screened" category in case-control studies even though BPH-related symptoms do not confer increased prostate cancer risk and odds ratios do not change with inclusion of symptomatic subjects in the analysis.

Screened subjects with LUTS should remain in the "screened" category in case-control prostate cancer screening studies since these symptoms may not be associated with increased risk of prostate cancer or validity of the odds ratio.