Prostate cancer 4/9/2010

PSA testing for prostate cancer debated; disease remains a killer 4/9/10

There have been a lot of scary stories in the media about the role of PSA testing for prostate cancer. One writer told a health magazine that he wanted his cancer back. He had read the two studies published in the New England Journal of Medicine and wrongly concluded that routine screening is not necessary. Hidden near the end of the article is this statement, “Nobody wants to die of it. So I guess it was a good thing my prostate was taken out.”
The greatest risk factor for prostate cancer is age. This risk increases significantly after the age of 50 in white men who have no family history of the disease and after 40 for black men and men with a close relative with prostate cancer. About two-thirds of all prostate cancers are diagnosed in men age 65 and older. About 80 percent of men who have reached 80 have prostate cancer. Medicare will only cover men over 50.
My concern is that older men, particularly those who do not like the PSA [prostate-specific antigen] test and DRE [digital rectal exam], will see these stories and say why bother testing. We should do less treatments but better screening.
National Public Radio interviewed a staff member, Richard Knox, under the title: Prostate Test: Lifesaver or Big Mistake? Knox talked to Richard Ablin, M.D. from the University of Arizona. Ablin discovered the PSA or prostate-specific antigen and now says the PSA test has become a public health disaster.
Ablin uses the analogy of the prostate gland as a box with no top. Aggressive cancer, the rabbit, can jump out of the box and spreads. The nonaggressive cancer, the turtle, just crawls around and goes no where. He is correct that the PSA test cannot tell you which cancer it is or even if you have cancer.
The April issue of the Johns Hopkins Prostate Disorders Health Alert discussed the quality of life issues after Prostate Cancer Treatment.
“Because prostate cancer progresses more slowly than other types of cancer, men can take some time to carefully consider the various prostate cancer treatment options. A man should talk with his doctor about the relative risks and benefits of each treatment and consider consulting physicians from different fields [urologists, radiation oncologists, and medical oncologists] to get a broader spectrum of opinions.”
The New England Journal of Medicine published two now famous studies a year ago, one American and one European. They are still being cited to suggest that PSA testing is not that important. Dr. Ruth Etzioni in Biostatistics of the Division of Public Health Sciences at the Fred Hutchinson Cancer Research Center pointed out several issues that put the research in the proper context.
The interpretations of the results of these studies are incorrect. Etzioni says, “The American trial is not a study of true screened and not screened as was the European trial.” That is because nearly one third of the supposed “not screened” did have tests so the American cancer death rates cannot be compared to the European results.
“There was too much focus on the American trial. You cannot just look at the number of deaths from prostate cancer, since not that many die from the cancer. You have to look at the percentage drop in the number of deaths for those who were screened. The European results showed a 20% drop in cancer deaths which I think is significant,” said Etzioni.
One PSA test is insufficient to recommend additional tests.
In early March, The American Cancer Society revamped its recommendations for prostate cancer screening. In new guidelines released the Society says that men who choose to be tested should get an annual screening if their level of prostate-specific antigen, or PSA, is 2.5 nanograms per milliliter or higher. But men whose PSA is under that threshold can be safely screened every two years. Men with a PSA level of 4.0 or higher should consider getting further evaluation, such as a biopsy. Previous guidelines had suggested that men with a PSA of less than 4.0 should be screened annually.
Next week: What should you do about prostate cancer screening?

Resources:
http://content.nejm.org/cgi/content/full/NEJMoa0810696?query=TOC
This is the American study.
http://content.nejm.org/cgi/content/full/NEJMoa0810084?query=TOC
This is the European study.
http://www.nejm.org/perspective-roundtable/screening-for-prostate-cancer/?query=TOC
Go to this website for the physicians’ discussion of the studies.