Prostate Cancer Differential Diagnosis

Alternate Names : Adenocarcinoma of the Prostate

Prostate Cancer Differential Diagnosis

The principal diagnostic mandates for the practitioner who screens patients for prostate cancer are (1) differentiation of prostate cancer from benign prostatic disease and (2) detection of prostate cancer when it is still localized to the gland, a clinical circumstance most amenable to curative therapy. The greatest diagnostic dilemma is presented by the asymptomatic patient with elevated PSA values. Benign prostatic hyperplasia and acute or chronic prostatitis may elevate the PSA. Indeed, up to 20% of men with biopsy-proven BPH may have abnormal PSA levels. In addition, some experts believe that occult prostate cancer detected by elevated PSA values may be biologically unaggressive and represent little threat to survival. Nevertheless, the PSA determination remains at the heart of accepted screening practice for prostate cancer. In the event that PSA alone is elevated, TRUS is recommended. If TRUS examination is normal, random biopsies of the prostate are often performed if the PSA level is greater than 4 ng/ml. If TRUS examination reveals abnormal (hypoechoic) areas, directed biopsies of these areas are performed. If biopsies do not reveal cancer, follow-up with annual PSA determination and DRE is continued.

Annual PSA screening should be performed in conjuction with DRE. DRE may detect 16% to 20% of prostate cancers in men whose PSA level is normal. In any circumstance in which a suspected palpable prostatic abnormality is perceived, TRUS and biopsy should be sought. Such abnormalities may include a nodule in one or both lobes of the prostate, asymmetry of the prostate, or induration of a lobe of the prostate. It is a daunting realization that up to 50% of apparently localized palpable abnormalities of the prostate ultimately shown to be cancer will be upstaged and extend beyond the capsule of the gland.

The presence of prostatic symptoms offers little assistance in differentiating patients with BPH from those with prostate cancer. PSA and DRE have some value in making this distinction. Cancer is more probable in men with elevated PSA levels or a palpable abnormality of the prostate. The emergence of symptoms of bone pain, weight loss, renal dysfunction, or anemia has little diagnostic value for prostate cancer. If prostate cancer is demonstrated in the setting of these symptoms, advanced, incurable disease is the rule.