Advances & Insights: Cancer
What the news means for you
Randall G. Rowland, MD, PhD
Early detection of prostate cancer saves lives
The real issue in prostate cancer screening is whether cancers are being discovered so early that patients are being treated unnecessarily. Eighty percent of men at autopsy have prostate cancer, at least microscopically. Almost one-third will have it by the age of 50. Compared to testicular cancer, which progresses rapidly, prostate cancer is usually very slow growing and may take 10 to 15 years before becoming a problem.
"Most urologists still feel the annual PSA and the DRE are the most reliable screening methods we have."
A study by the Mayo Clinic several years ago looked at age and time of diagnosis of prostate cancer and the estimated age when the tumor would reach a life-threatening volume. They found that only 12-14 percent of patients were being overtreated. That means 86 percent needed the treatment, which is a reasonable number.
Most urologists still feel the annual PSA and the DRE are the most reliable screening methods we have. In recent years, the upper limit of normal PSA has changed from 4 to 2.5 and that triggers the possibility of biopsy in a lot more patients. But previously, too many cancers were going undetected.
Tests being refined
There are other factors that may prompt a biopsy besides an elevated PSA. Along with the absolute numbers, we also look at velocity—how much the PSA is rising. A PSA velocity between 0.7 and 1.0 change per year is considered significant. We’ve found many cancers using that measurement.
Additionally, there are other PSA derivatives—a free and total PSA or a complex PSA. This has to do with the percentage of PSA that exists in the blood as a free molecule versus one bound to proteins. There is an association between a low percentage of free PSA and a higher risk of malignancy.
So there are still ongoing efforts to improve the reliability of this test by looking at some of the derivatives. In the case of patients who have borderline situations such as a previous negative biopsy, testing for these factors will help determine whether to do additional biopsies. Other studies are looking at potential markers in the blood that would indicate a tumor, but nothing is currently on the horizon that would replace the PSA test.
"Annual screening with the PSA and DRE should be performed for all men age 50 and over."
Who should be screened?
In the early years of my practice, by the time we saw patients with prostate cancer, 80 percent were beyond curing. Now, for the first time in 40 years, mortality rates for prostate cancer are declining. Most physicians believe that is because we’re seeing patients earlier due to screening and increased awareness of the disease. People in general are more open to talking about health issues, and there are also several celebrities who have publicly discussed their experience with prostate cancer.
Annual screening with the PSA and DRE should be performed for all men age 50 and over. High-risk groups such as African-Americans and all men with a family history of prostate cancer should be screened annually starting at age 40 or 45.
We discuss all treatment options with our patients, and that sometimes includes no treatment. If someone has a nonaggressive tumor and a life expectancy of less than 10 years, we would probably be content with no intervention.
In all other cases, the major treatments for localized tumors include:
Radical prostatectomy, which can be done as an open or laparoscopic surgery.
External radiation—either traditional radiation, three-dimensional conformal radiation therapy or IMRT.
Brachytherapy, treatment with radioactive seeds placed into the prostate.
The prediction as to whether a tumor is likely to be confined to the prostate is based on the PSA level, the Gleason score of the prostate biopsy and the rectal findings. How you choose among the treatments is based somewhat on the patient’s age and existence of other serious medical conditions. Retrospective studies comparing treatment options suggest that younger patients do better with surgery.
Whether a man will experience impotence as a result of surgery for prostate cancer depends very much on his age. People in their 50s who have good sexual function prior to surgery have about a 70 percent chance of being able to achieve a spontaneous erection. That number decreases to about 60 percent at age 60 and 50 percent or less at age 70. Oral medication such a Viagra as well as other treatments will help many of those still having problems.
With the traditional standard external radiation, about one-quarter to one-half of the patients become impotent, most likely due to scarring of the blood vessels to the penis. Slightly fewer patients seem to be impotent following brachytherapy.
Dr. Rowland is a urological surgeon associated with the UK Markey Cancer Center and professor and James F. Glenn chair of urology at the UK College of Medicine.
Prostate cancer screening, treatment debated
In 2006 more than 230,000 men in the U.S. will be diagnosed with prostate cancer, according to the American Cancer Society. It is the second leading cause of death by cancer in men, ranking just behind lung cancer.
When detected early, the five-year survival rate for prostate cancer is nearly 100 percent.
Prostate cancer often does not produce symptoms in its early stages. Yet, when detected early, the five-year survival rate for this cancer is nearly 100 percent. But can routine screening for prostate cancer reduce the number who will die from
Two screening methods
New research suggests that two tests performed millions of time a year in the U.S. may actually fail to save lives. The study was based on data from 1991 to 1999 on 1,002 patients treated at 10 Veterans Affairs medical centers in New England. Findings were published August 21, 2006, in the Archives of Internal Medicine.
Two screening tests were evaluated: 1) the prostate-specific antigen (PSA) test and 2) the digital rectal exam (DRE). The PSA test is a blood test that looks for a protein made by the prostate gland. An elevated level may indicate cancer or other conditions such as benign hyperplasia or prostatitis. The DRE is useful in detecting cancers in men whose PSA levels are normal.
Researchers compared 501 men with prostate cancer who had died from that disease or other causes with a control group of 501 men who were still alive and matched the first group in age and other factors. Because they were looking at whether screening is effective in improving survival, any tumor found had to be both potentially fatal and curable.
Results of VA study
The researchers found that the men who were alive were no more likely to have received the screening tests than those who died. The study was based on data from the early 1990s, prior to the development of more sensitive PSA testing. Further information on the benefits of screening should be available in 2009 when results from large studies of the PSA test in 300,000 U.S. and European men are expected.
For now, however, the researchers in the VA study concluded, “. . . the uncertainty of screening should be explained to patients in a process of ‘verbal informed consent,’ promoting informed decision making.”
Experts differ on benefits of screening
The U.S. Preventive Services Task Force reported in 2002 that it also found insufficient evidence for recommending routine screenings for prostate cancer. But medical organizations differ in their recommendations. The American Cancer Society and the American Urological Association advise prostate cancer screenings for all Caucasian men over 50 and for African-Americans beginning at age 40-45.
The main point of contention is that prostate cancer is a slow-growing disease that may never cause symptoms or death in some men. In addition, the PSA test does not distinguish between aggressive and less aggressive prostate cancers. Catching the cancer in the very early stages may result in treatment that is worse than the disease itself. For example, surgery and radiation treatment for prostate cancer can cause incontinence and impotence.
If either the PSA test or the DRE is abnormal, a biopsy is usually performed by transrectal ultrasound. If a malignancy is found, there are many different treatment choices, ranging from surgery and radiation therapy to watchful waiting. In most cases, the patient has plenty of time to make a decision, since prostate cancer usually grows
For more information, see:
The effectiveness of screening for prostate cancer: A nested case-control study, Archives of Internal Medicine, v. 166, no. 1, January 9, 2006, pp. 38-43 (free registration required)
Cancer risk assessment and screening programs, Markey Cancer Center, UK HealthCare
Prostate cancer fact sheet, Health Information, UK HealthCare
Learn about prostate cancer, American Cancer Society
Prostate cancer, Health Information, UK HealthCare
Prostate biopsy, Health Information, UK HealthCare
Genitourinary Team, Markey Cancer Center, UK HealthCare
UK HealthCare Cancer Services - Markey Cancer Center
For more information, or to make an appointment with a UK HealthCare physician, please call UK Health Connection at 1-800-333-8874.