Does screening for prostate cancer identify clinically important disease?

摘要

In this study the combination of digital rectal examination (DRE) and serum prostate-specific antigen (PSA) is shown to be effective for detecting early prostate cancer in a urological out-patient setting. PSA provides the means to detect cancer in men with normal DRE that may otherwise present as so-called incidental cancer at transurethral resection of the prostate (TURP) for apparently benign disease or later in the course of its natural history as locally advanced or metastatic disease. PSA progression in men with incidental cancer has been previously demonstrated to be predicted more reliably by residual cancer on needle biopsy after TURP than by tumour in the resected specimen and, therefore re-staging such patients is worthwhile when further treatment would be considered. Among men selected for radical prostatectomy, non-palpable tumours detected with PSA more predictable in pathological extent than incidental cancer and their particular pathological characteristics suggest they include clinically significant tumours that would progress if untreated to palpable and eventually metastatic disease. In view of this progressive behaviour, cancer detected by PSA should be considered clinically significant particularly in men with a life expectancy of at least 10 years. Therefore screening should be offered for such individuals, to detect and treat tumours at a curable stage and thereby eliminate the high mortality and often protracted morbidity commonly associated with metastatic disease.