Recently there's been quite a bit of talk about prostate cancer screening and diagnosis in the media. This is due to two landmark articles released this past year that had conflicting results as to whether routine screening with PSA is worthwhile. With this column we hope to clarify some of the issues and give you some general information about prostate cancer, its diagnosis and treatment.
The prostate is a gland that sits beneath the bladder in men that adds liquid to the semen to aid in reproduction. Abnormal growth of these glands can lead to prostate cancer. This is different than the overgrowth of normal glands which leads to benign prostatic hypertrophy.
Prostate cancer is the most common cancer in American men, excluding skin cancer. According to the National Cancer Institute and American Cancer Society, it is estimated that prostate cancer will affect 192,280 men this year and cause 27,360 deaths. Age, African-American race and positive family history are risk factors for prostate cancer. The disease is uncommon in men younger than 50. The lifetime risk of being diagnosed with prostate cancer is about 17.1 percent and the lifetime risk of dying from prostate cancer is 2.9 percent. The majority of cancers are diagnosed while still locally confined to the prostate with approximately 5-7 percent being at an advanced stage at diagnosis.
The benefit of screening for prostate cancer is controversial but screening does lead to diagnosing more prostate cancer that is locally confined. This may allow for more treatment options.
Two recent clinical trials reported conflicting data regarding the impact of screening on death from prostate cancer. In one trial (Prostate, Lung, Colorectal and Ovarian Cancer Screening trial) no benefit to screening was found at 7 years follow-up and screened patients had as much chance of dying from prostate cancer as unscreened patients. In contrast, another trial (European Randomized Study of Screening for Prostate Cancer trial) found screened patients were 20 percent less likely to die from prostate cancer.
The American Urologic Association's current stance is that risk assessment should be offered to men starting at the age of 40 who have a life expectancy of over 10 years. Other data suggests that men over age 75 with a PSA of <3ng/ml may not need further screening as their risk of prostate cancer death is low.
There are a variety of screening methods. PSA, prostate specific antigen is an enzyme released by prostate cells and is currently the best screening blood test for prostate cancer. The confounding factor is that it is also elevated in BPH, which is common in the same age group of men at greatest risk for prostate cancer. There are several methods of interpreting PSA in an attempt to make it more accurate in predicting cancer. These strategies are helpful but still do not allow an absolute diagnosis without prostate biopsy. The digital rectal exam is used in addition to PSA to detect any abnormal areas around the prostate gland. It is an important part of prostate cancer detection since a minor amount of patients may have a low PSA with a palpable prostate cancer nodule.
To diagnose prostate cancer, an abnormal PSA or DRE will be followed by a prostate biopsy. Whether or not an individual patient should have regular screening or biopsy of the prostate is an intricate decision making process to be made after careful discussions between the patient and his urologist. Prostate biopsy is done under ultrasound guidance, usually in the outpatient setting. From the biopsy, PSA, and DRE the urologist can determine the clinical stage of the cancer.
Based on the overall health of the patient and the clinical characteristics of the cancer a treatment plan can be individualized. The main treatment options include active surveillance, surgery - either minimally invasive or open, radiation therapy, or hormone therapy. Some of the new methods include robotic prostatectomy and brachytherapy. Rarely chemotherapy is used in advanced disease. There are other therapies that are being investigated such as cryoablation and proton therapy.
Prostate cancer screening, diagnosis, and treatment options can be confusing, especially with the recent media attention to the benefits of screening. It is best for each individual to discuss these topics with a qualified urologist.
Bert Chen M.D. and Allen Futral, M.D are in practice at Georgia Urology, P.A.