Mammography Doesn’t Come Without Risk
The updated federal guidelines announced by Health and Human Services Secretary Tommy Thompson on Thursday strongly recommending annual screening mammography for women over the age of 40 are unlikely to resolve the current debate. The guidelines, surprisingly based on an unpublished analysis by an independent advisory board, ignore evidence on the risks of breast cancer from mammography.
Furthermore, they dismiss evidence on the effectiveness of monthly breast self-examination combined with annual clinical breast examination by trained health care professionals. None of these concerns are relevant to diagnostic mammography, the value of which is unchallenged.
Screening mammography poses significant and cumulative risks of radiation, particularly for premenopausal women. The routine practice of taking four films of each breast annually results in approximately 1 rad (radiation absorbed dose) exposure. This is about 1,000 times greater than exposure from a chest X-ray, which is broadly focused on the entire chest rather than narrowly on the breast. The premenopausal breast is highly sensitive to radiation, each 1 rad exposure increasing breast cancer risk by about 1%, with a cumulative 10% increased risk for each breast over a decade’s screening.
Radiation risks are further increased fourfold for the 1% to 2% of women who are unknowing silent carriers of the A-T (ataxia-telangiectasia) gene. By some estimates, this accounts for up to 20% of all breast cancers diagnosed annually.
All these risks are greater for women in their 30s, who are being encouraged to undergo “baseline screening,” for which there is no evidence of any future relevance.
Since 1928, physicians have been warned to handle cancerous breasts with care, for fear of accidentally disseminating cells and spreading the cancer. Mammography entails tight and often painful breast compression, particularly in premenopausal women. This may lead to the lethal spread of malignant cells by rupturing small blood vessels in or around small undetected breast cancers.
Another serious danger of mammography is the fact that mammography centers are being overbooked as a result of the aggressive promotion of premenopausal screening. Patients referred for diagnostic mammography because of suspicious clinical or other findings are now experiencing potentially life-threatening delays of up to several months before they can be examined.
The advisory panel’s dismissal of self-examination and clinical examination is inconsistent with the results of a September 2000 publication by leading University of Toronto epidemiologists. Based on study of breast cancer mortality in 40,000 women, it was concluded that monthly self-examinations following brief training coupled with an annual examination by a trained health care professional is at least as effective as screening mammography in detecting small tumors.
National networks of clinics staffed by nurses trained in teaching monthly self-examination and conducting annual clinical examination should be established to replace mammography screening. Apart from their minimal costs, such clinics would empower women and free them from increasing dependence on industrialized medicine and complicit medical institutions.
It should be further pointed out that the new federal guidelines ignore the growing and inflationary costs of mammography. Screening all premenopausal women, 20 million annually, would cost about $2.5 billion. That is equal to 14% of estimated Medicare spending on prescription drugs. These costs would be increased fourfold if the highly profitable machine and film industries succeed in replacing film machines, which cost about $100,000 each, with the latest high-tech digital machines, which cost about $400,000 each. The latter have been approved by the Food and Drug Administration although there is no evidence of improved effectiveness.
Finally, it may be noted that no nation other than the U.S. recommends routine screening of premenopausal women.
