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An argument to do prostate biopsies on even more men
(November 2004)

It is said that 75 percent of men over age 50 have had determinations of prostate specific antigen (PSA) in their bloods. Levels over 4 nanograms suggest the presence of prostate cancer and lead to biopsies, although most elevated PSA levels are due to prostate enlargement or other causes and are not due to cancer. Investigators writing in the July 24, 2003 issue of The New England Journal of Medicine now argue that the cutoff of 4 nanograms for recommending biopsy is too high and that it misses too many of the prostate cancers. These conclusions are based on study of 6,691 men who underwent PSA screening; of 705 who had PSA levels over 2.5 nanograms and subsequently had prostate biopsies, 182 were found to have prostate cancer. Based on their data, the authors suggest that men under age 60 with PSA levels over 2.5 nanograms should have biopsies.

According to this study, at a cutoff of 4 nanograms, 82 percent of prostate cancers among men under age 60 would be missed. Reducing the cutoff level to 2.6 nanograms would still result in missing 64 percent. Over age 60, if 4 nanograms is used as the cutoff for biopsy, only 35 percent of prostate cancers would be detected; lowering to 2.1 nanograms the level requiring biopsy would detect 68 percent of the cancers, but would also result in an unacceptably high false positive rate. That is why the recommendation for lowering the level at which biopsy would be carried out to above 2.5 nanograms is made particularly for those under age 60; in that age group, a greater percentage of cancers would be detected, but there would only be a small increase in false positives. However, the authors leave open the possibility of lowering the level for those over age 60, as well.

An accompanying editorial points out that those with PSA levels of 2.0 to 2.9 nanograms have a 7.4 percent likelihood of actually having prostate cancer on biopsy; at PSA levels of 3.0 to 3.9, the likelihood of detecting cancer by biopsy is 12 percent. So, below 4 nanograms, the likelihood of the biopsy being unnecessary (or at least not helpful to the patient) is 88 to 92.6 percent. Even with a PSA level of 4 to 9.9, which is considered a definite reason for biopsy, the likelihood of the biopsy showing cancer is a little less than 1 in 4. Only when the PSA is over 10 is it more likely than not that a biopsy will be positive for cancer.

There are all sorts of problems with the PSA test and prostate cancer:

1. This study says the test fails to pick up most prostate cancers.

2. There are too many false positives - unneeded biopsies; and the biopsies are unpleasant and can be dangerous.

3. Thus far, we do not have the evidence to show that detecting cancer by the PSA test actually saves lives. We should know in a few years whether or not it does save lives.

4. It is known that most prostate cancers will never progress and will never produce symptoms. The PSA does not distinguish between the majority of prostate cancers that will never progress and the minority that will progress resulting in about 30,000 deaths a year in the United States.

5. If the PSA level is high and the biopsy shows cancer, it is not clear whether the treatment (surgery or radiation) makes a difference, but it is clear a large percentage of the men will suffer treatment complications, including impotence and incontinence.

Many of the proponents of PSA testing with prostate biopsies for high levels and then radical operation or radiation treatment of detected cancers would have us believe the treatment is reasonably benign. The facts are otherwise. A report in the September 15, 2004 Journal of the National Cancer Institute analyzed complications five years after surgery or radiation treatment in more than 1,000 men. Here are the results:

- Almost 80 percent of those treated surgically suffered from impotence as did almost two-thirds of those treated with radiation.

- Fifteen percent of those treated surgically and 4 percent of those given radiation were incontinent.

- More than 25 percent of those treated with radiation had bowel complaints, as did more than 10 percent of those treated with surgery.

Only one conclusion is possible - a lot of men undergoing treatment for prostate cancer suffer from long-term complications - sexual dysfunction, urinary incontinence, or bowel disturbances. If the frequency of complications is that high, we had better be sure that PSA screening and treatment of the cancers detected in men with no symptoms results in the saving of lives or significant prolongation of good quality life. So far, we have no such evidence.

6. As this study shows, it is not clear at what PSA concentration a biopsy should be performed. That is distressing considering most men over age 50 are undergoing the test even though it is not known whether the test actually saves any lives.

Healthful Life will not recommend the PSA test as a routine screen for men over age 50 until the evidence clearly shows that the test and resulting early detection of prostate cancer actually saves lives or, at the very least, significantly prolongs good quality life.. Several studies are ongoing; reasonably definitive results should be available by 2005 or 2006.

Punglia, R.S., et al. Effect of verification bias on screening for prostate cancer by measurement of prostate-specific antigen. The New England Journal of Medicine. Vol 349 (July 24) Pgs 335-342, 393-395. 2003.