Prostate Cancer: Diagnosis and Treatment

Diagnosis

The presence of an indurated area of the prostate, gland asymmetry, or a palpable nodule detected during digital rectal examination is suggestive, but malignancy may be present even with a normal prostate exam.

Most cases are detected by PSA screening. PSA is a very sensitive but nonspecific test. Most elevated PSA results are false–positive for cancer, and reflect chronic prostatitis or benign prostatic hyperplasia. This has led to considerable controversy about the meaning of an elevated PSA reading. Higher PSA velocity or shorter doubling time may help distinguish elevated PSA due to prostate cancer from that due to benign prostatic conditions. PSA also reliably reflects the effectiveness of treatment and disease activity after recurrence.

Prostate biopsy, usually via transrectal ultrasound, is necessary for definitive diagnosis.

Tumors are staged according to the TNM (tumor, node, metastasis) classification, Whitmore–Jewett system, or surgical staging. Metastatic survey may include bone scan, CT scan of the abdomen and pelvis, and ProstaScint scan (using monoclonal antibodies specific for prostate–specific membrane antigen).

Treatment

Due to the indolent nature of most cases of prostate cancer, careful monitoring of tumor growth without active treatment can be an acceptable option, particularly with older patients.

Treatments for localized disease include radical prostatectomy, external beam radiation, internal radiation (brachytherapy), and cryotherapy. Radical prostatectomy and, to a lesser extent, external beam radiation often result in some degree of urinary incontinence and impotence. Brachytherapy tends to be associated with irritative voiding symptoms.

Gonadotropin–releasing hormone (GnRH) agonists (eg, leuprolide), androgen receptor antagonists (eg, flutamide), and, to a lesser extent, orchiectomy are used as androgen–deprivation therapies to reduce circulating testosterone. These treatments may be used as primary or adjuvant therapy for localized disease, but are most commonly used as a primary therapy for advanced disease or for palliation of symptoms from metastatic disease.

Chemotherapy for prostate cancer is sometimes used for hormone–refractory prostate cancer and is under investigation as a treatment option for earlier stages of the disease.

Exercise may prove beneficial. In men aged 65 years or older, a 66% lower risk for advanced prostate cancer and 74% lower risk for fatal prostate cancer were found in the highest category of vigorous activity.¹ Other studies have concluded that a high level of physical activity is not associated with prostate cancer risk overall, but does reduce the risk for developing aggressive prostate cancer.²