JAMA: Breast and Prostate Cancer Over-Screening Dangerous

by Tony Isaacs

A new analysis published this month in the Journal of the American Medical Association (JAMA) found that screening for prostate cancer and breast cancer both have a problem that runs counter to everything people have been told about cancer: The screenings are resulting in finding cancers that do not need to be found because they would never spread and kill or even be noticed if left alone. That has in turn led to a huge increase in cancer diagnoses of innocuous cancers would have otherwise gone undetected.

At the same time, the analysis, "Rethinking Screening for Breast Cancer and Prostate Cancer" also found that both screening tests are not making much of a dent in the number of cancers that actually are of a deadly variety. That could be because many lethal breast cancers spread rapidly and gain a foothold between mammograms. The deadly prostate cancers, on the other hand, have often already spread at the time of cancer screening. The dilemma for breast and prostate screening is that it is not usually clear which tumors need aggressive treatment.  Many believe that a major reason that is not clear is because studying it has not been much of a priority.

"The issue here is, as we look at cancer medicine over the last 35 or 40 years, we have always worked to treat cancer or to find cancer early," Dr. Barnett Kramer, associate director for disease prevention at the National Institutes of Health, said. "And we never sat back and actually thought, 'Are we treating the cancers that need to be treated?' "

Finding insignificant cancers is the reason the breast and prostate cancer rates soared when screening was introduced, Dr. Kramer said. And those cancers, he said, are the reason screening has the problem called overdiagnosis - labeling innocuous tumors cancer and treating them as though they could be lethal when in fact they are not dangerous.  

"Overdiagnosis is pure, unadulterated harm," he said.  

Dr. Peter Albertsen, chief and program director of the urology division at the University of Connecticut Health Center, said that had not been an easy message to get across. "Politically, it's almost unacceptable," Dr. Albertsen said. "If you question overdiagnosis in breast cancer, you are against women. If you question overdiagnosis in prostate cancer, you are against men."

A previous study by researchers from the University of Nebraska and the John H. Stroger Jr. Hospital of Cook County, Ill cast doubt on the widespread assumption that regular mammograms save lives, showing that 2,970 women must be screened for breast cancer in order to prevent even one death.

"For a woman in the screening subset of mammography-detectable cancers, there is a less than 5 percent chance that a mammogram will save her life," wrote the researchers.

Sources included:

http://www.nytimes.com/2009/10/21/health/21cancer.html
http://www.docstoc.com/docs/13462020/JAMA_10_21 
http://www.naturalnews.com/026880_cancer_brst_cancer_cancer_screening.html