Upfront
The case for early detection and effective treatment for prostate cancer: Accumulated evidence
by
Ralph Valle

Ralph Valle, a founding member of Prostate Cancer Action Network (PCAN) lives in Arizona. Ralph writes on Prostate Problems Mailing List (PPML) and volunteers for ACS.

June 1, 2000. Many physicians and unfortunately many primary care doctors have a confused concept of prostate cancer screening. Lack of clinical trials that demonstrate the advantage of screening and the health care industry's exploitation of this lack of certainty to "fan the flames" make a powerful argument against prostate cancer screening.

Half or more of primary care doctors do not offer PCa screening even to men at risk. Because of lack of clinical trials, the American Cancer Society, the National Cancer Institute and other organizations take a conservative approach to PCa screening. Their logic is, if there is no proven certainty of benefit, why even bother?

Tests such as PAP smear for cervical, mammography for breast and possibly occult blood in fecal matter for colon can help detect cancer at an early stage. Earlier stages, while the cancer is localized, generally are considered more manageable. Detection at those early stages results in better treatment outcomes than for disease that has escaped the primary organ and produced metastasis.

The PAP smear was adopted even though no clinical trials had been performed. Simply the widespread use of the test resulted in a reduction of the mortality rate for gynecological cancers. Why not apply the same logic to PSA testing, when we can already see results that do indicate that early detection and treatment of early prostate cancer can result in a survival benefit.

Prostate cancer impacts both men and their families. In the U.S. it is the most diagnosed cancer in men and the second cause of cancer death. Here, a man is diagnosed every 3 minutes and one dies every 14 minutes(1). And unfortunately, men as they age are not properly informed or even aware of the risks of prostate cancer.

Is the high incidence and mortality of prostate cancer representative of a significant disease? Of course it is. Should men and their families be aware of such disease? Of course they should, but in spite of this a major medical/political/economic controversy drags on. The result is, men and their families get mixed and confusing signals about the usefulness of prostate cancer screening.

At present, prostate cancer is not preventable and all forms of treatment are more effective in the early stages of the disease. If prostate cancer cells escape the confine of the prostate, treatment becomes very difficult and the disease has a much higher mortality rate. Early detection and treatment therefore become critically important.

Testing with prostate-specific antigen (PSA) and digital rectal examination (DRE) are the only available methods to detect early stages of prostate cancer.

Prior to the widespread use of the PSA test (just over a decade ago) 70% of men diagnosed with prostate cancer were diagnosed with advanced stages of the disease. Now, because of more frequent use of PSA and DRE, 70% of men are diagnosed with earlier stages(2). There is no question that PSA and DRE are responsible for this shift in stage at diagnosis. The opinion of those opposed to testing for prostate cancer is itself inconsistent. On one hand, they claim the test is not sensitive enough, and at the same time they claim it discovers too much insignificant cancer.

How can this be? Medical opinion is highly divided about the benefits of combined PSA and DRE testing. According to detractors, testing produces many false positives/false negatives and creates stressful problems in men's lives. Why then, has this test been instrumental in the shift of stage at diagnosis? If the test can detect earlier stages of prostate cancer when the disease is more treatable, is it not likely to benefit those tested? Why is this benefit in detecting earlier stages of the disease ignored?

When confronted with this irrefutable fact, critics point to the fact that PSA discovers many cases of cancer that need not be treated. They argue that treatment for prostate cancer results in more harm than good by diminishing the quality of life of those treated. What is worse, they claim, treatments do not improve the survival outcome when compared to simple observation of the disease. These positions ignore the fact that in the absence of testing, most prostate cancer will be diagnosed in advanced stages with very limited possibility of cure.

These questions are hashed and rehashed because until now, we have not had definitive proof through randomized trials. Some of the trials that are now under way will not yield information for at least another five years. Should we ignore preliminary evidence as to the benefit of early detection with PSA and DRE? Should we ignore the result of the first randomized controlled prostate cancer screening trial(3)? Critics have ignored the results of this significant study and also that of a population-based study that clearly indicate the benefit of treatment over simple observation(4). Why?