Sunday, 25 October 2009
© 2009 by Ralph W. Moss, Ph.D.
http://www.cancerdecisions.com/content/view/281/2/lang,english/

There appears to be discord at the top of the American Cancer Society (ACS) over the promotion of breast cancer screening. According to a front-page article in the New York Times, the ACS intends to abandon its rigid advocacy of mammography screening of the age 40+ female population. The Times states that in early 2010 the ACS will modify its long-held position. The stated reason is that screening mammography does not actually save many lives, since it mainly detects innocuous tumors that will never become life threatening. Meanwhile, it fails to detect most of the dangerous tumors. But a press release from the ACS soon afterward directly contradicted its own medical director’s stated positions.

The failure of mammographic screening has been widely discussed for years and so the “news” was that the ACS was going to finally acknowledge this reality. “The American Cancer Society,  which has long been a staunch defender of most cancer screening,” wrote Times science reporter, Gina Kolata, “is now saying that the benefits of detecting many cancers, especially breast and prostate, have been overstated” (Kolata 2009).

Breast cancer thus turns out to be much like prostate cancer. In prostate cancer, the use of the prostate specific antigen (PSA) blood test has created an “epidemic” of new cancers, most of which would never have progressed to become life-threatening conditions. Doctors have been busy “curing” artifacts of the testing process itself. Widescale PSA screening turned many otherwise healthy men into traumatized cancer patients. Anxiety over one’s PSA level became a disease in its own right called “PSA-itis,” to quote the distinguished Toronto oncologist, Ian F. Tannock, MD (Lofters 2002). Meanwhile, deadly forms of prostate cancers-which are rapid growing and prone to metastasize-are less likely to be detected through PSA screening in time to make a survival difference.

Criticism of Mammography

There have been similar criticisms of mammography over the years. One thinks of the efforts of John Bailar, MD, PhD, a former editor of the Journal of the National Cancer Institute, who, starting in 1976, vigorously disputed the efficacy of mammography. One also thinks of Samuel Epstein, MD, of the University of Illinois, who pointed out the danger of the radiation involved in repeated mammograms. I myself wrote critically about mammography in my book The Cancer Industry (1980) and in a more recent Moss Report on the topic (see below).

A lucid discussion of the uncertainty of cancer screening has been made by H. Gilbert Welch, MD, and colleagues at the VA Outcomes Group and the Dartmouth Institute for Health Policy and Clinical Research, White River Junction, VT. Welch is the author of a provocative book, Should I Be Tested for Cancer? Maybe Not and Here’s Why (2005) as well as numerous articles. For example, Dr. Welch wrote in 2009 in the British Medical Journal:

“Overdiagnosis of cancer occurs when the cancer grows so slowly that the patient dies of other causes before it produces symptoms or when the cancer remains dormant (or regresses). Because doctors don’t know which patients are overdiagnosed, we tend to treat them all. Overdiagnosis therefore results in unnecessary treatment” (Welch 2009).

This week, the ACS dam appeared to be breaking, as a result of a recent article in the Journal of the American Medical Association, reiterating many of Welch’s points. The lead author was Laura J. Esserman, MD, a breast surgeon at the University of California, San Francisco. According to the Times, the ACS was “spurred in part by an analysis published Wednesday in The Journal of the American Medical Association.” This JAMA article shows that there has been a “40 percent increase in breast cancer diagnoses and a near doubling of early stage cancers, but just a 10 percent decline in cancers that have spread beyond the breast to the lymph nodes or elsewhere in the body” (Kolata 2009).

This contradicts the very purpose of mammography screening, which is to find breast tumors in an early and curable stage, before they become deadly. If that were indeed happening, then the statistical increase in early-stage breast cancer should be accompanied by an equivalent decrease in the number of late-stage tumors. Instead, there was only a 10 percent decrease in late-stage cancers. So the net effect has been to greatly increase the number of breast cancer cases, finding innocuous pseudo-malignancies, without significantly impacting the death rate.

As the JAMA paper put it, mass screening increased “the burden of low-risk cancers without significantly reducing the burden of more aggressively growing cancers and therefore not resulting in the anticipated reduction in cancer mortality” (Esserman 2009). Or, to quote the Times, there was a “real risk of over-treating many small cancers while missing cancers that are deadly.”