Medical: Breast Cancer Prevention ... History of a Mistaken Approach

Breast cancer has remained the foremost cause of cancerous death of U.S. women during the past century for those not smoking, despite much-publicized early detection campaigns with aggressive surgery, radiation therapy, chemotherapy, and anti-hormone therapy. Unfortunately, the early detection and aggressive treatment of breast cancers has failed to achieve progressive reduction in national breast cancer death rates.

By contrast, prevention of fatal uterine cancer by early detection of neoplasia through annual pelvic examinations and Pap smears, coupled with ablative therapy and with some help from oral contraceptive use and avoidance of smoking, has reduced the age-adjusted death rate from uterine cancer by 80 percent during the last seven decades — a tremendous accomplishment!

A Puzzling Enigma

How can it be that while there is general belief in the value of early detection/treatment of breast cancer, the national age-adjusted death rate from this disease has remained relentlessly at the same high level for several decades despite the large increase in the last two decades in early mammographic detection followed by aggressive therapy?

Understandably, this is because the claims of therapeutic success have been largely based upon the usual finding that a substantially higher proportion of breast cancer patients diagnosed by mammography and treated by surgery and radiation are alive five and ten years following treatment than otherwise-identified patients. Upon casual inspection, the salutary effects of such treatment seem obvious, nicely fitting the concept that early detection/treatment of breast cancer saves many lives — as it certainly would if we were dealing largely with cancers metaphorically identified as"Rabbit Tumors" in the following classification by George Crile:

"Bird Tumors" are cancers which are so highly malignant and"flighty" that they ordinarily metastasize before they can be successfully detected and treated.

"Rabbit Tumors" are cancers of intermediate malignancy, becoming dangerously malignant and"jumpy" with time, but curable by early detection and treatment; witness cervical cancers and skin cancers.

"Turtle Tumors" are cancers inherently so weakly malignant and indolent that they can ordinarily be cured by ablation when they become apparent.

The most likely interpretation of the unyielding continuation of traditional age-adjusted death rates from breast cancer in the United States during this century, despite heroic efforts at detection and early drastic treatment, is that such cancers are mainly"Birds" and"Turtles," for which surgery is less useful than it is for"Rabbits," and thus early detection and treatment — including costly and intrusive surgeries — prevent few breast cancer deaths. Women are indeed surviving for years after detection and treatment but, on average, appear to be surviving no longer than they would have without detection and treatment

Elusive Benefits

Despite inadequate validation of the value of mammography, a powerful combination of fearful women, willing physicians and surgeons, merchants of mammographic equipment and clinical services, health agency bureaucrats, and politicians have ballooned the use of mammography far beyond its demonstrated intrinsic merits — to the point that in the United States in 1994, 61% of women over age 40 (about 32 million) reported having had mammograms during the past two years. Interpretations of these deca-millions of mammograms increased diagnosed breast cancer incidence and also generated more than 5 million false positive diagnoses of breast cancer — causing great psychic and financial trauma to many millions of women. The total health care costs generated by the current exuberant practice of mammography in the United States cannot be calculated exactly but surely exceeds ten billion dollars annually.

The more than 100 million mammograms performed in the United States during the last decade increased the number of diagnosed breast cancer cases — and led to treatments that often reduced quality of life — but the wave of mammograms failed to reduce mortality from breast cancer, which was at 25.1 deaths per 100,000 women in 1995 - the same level as in 1930.

Mammographic screening is being promoted in the belief that it leads to earlier diagnosis and treatment and thereby extension of life. But one must be ever mindful that it sometimes leads to a shortening of life from"therapeutic misadventure" due to adverse effects of surgery, radiation and chemotherapy. Some women who would have lived many years without mammographic screening die an early death because of early detection of incipient neoplasia and resultant treatment. This seems a likely explanation for the slight increase in breast cancer death rates seen in the 1980s and may also be a reason for the slight decrease in death rates seen in the early 1990s.

Some decrease in breast cancer deaths in the 1990s would necessarily follow from the heaping of"therapeutic misadventure" deaths in the 1980s, causing some patients to die too early to appear in the statistics for"natural deaths" from breast cancer in the 1990s. Although a death due to grievous adverse effects of therapy should be certified as a"therapeutic misadventure" and coded thereto, this rarely happens because physicians ordinarily certify the death as due to breast cancer: the diagnosis that led to the tragic sequence of events. Increased use of the anti-hormone tamoxifen for the prevention of breast cancer recurrence probably has contributed to a slight decrease in breast cancer mortality during the last few years.

Would Women Have Been Better Off Without Treatment?

We do not know at exactly what level breast cancer death rates would have been throughout this century if there had been no aggressive detection and treatment of breast cancer because breast cancer incidence and fatality levels have been buffeted by a maelstrom of determinants, sometimes acting synergistically and sometimes conflicting: changes in childbearing and breast-feeding, in nutrition and daily life, in contraceptive use and smoking, in the detection and treatment of breast cancer, in the occurrence of competing causes of death and in the classification of deaths by cause. Yet we do know that excessive promotion of mammographic screening in the 1980s and '90s has generated excessive agony and heavy costs for many millions of women, without much demonstrated utility.Currently, many of the women surviving after mammography and treatment have the borderline condition known as"ductal carcinoma in situ," and would have survived equally well without mammographic diagnosis and aggressive treatment.

The situation is reminiscent of the lung cancer control campaigns of the 1950s and 60s, when the American Cancer Society and many agencies urged all smokers to have chest x-rays every six months for early detection and treatment of lung cancer, thus diverting smokers and the public from primary prevention and providing profitable business for the medical-industrial-complex but making no substantial improvement in lung cancer five-year survival rates, which continued at about 5%. This century's experience has certainly demonstrated that the only effective way to control lung cancer is by primary prevention: by avoidance of the smoking of tobacco.

Likewise, clinical and public health practitioners must now confront the tragic fact that the main breast cancer control strategy of this century—early mammographic detection followed by aggressive surgery, radiation, and chemotherapy—has perhaps been a costly, traumatic, and general failure. Even the desperate measure of bone marrow ablation and transplant regeneration has failed to extend the lives of those with progressive breast cancer.

Hope

There are immediately at hand precious few preventive measures of demonstrated utility in the prevention of breast cancer, but drugs such as raloxifene and tamoxifen can cut breast cancer mortality among users to less than half. Though their effects must be further studied, these drugs provide an opportunity for a revolutionary shift in the dominant public health strategy against breast cancer: away from the early detection - aggressive treatment campaign, toward a new era emphasizing prevention of breast cancer by drug prophylaxis. In addition, there is the preventive surgical enucleation of glandular breast tissue, which can cut breast cancer mortality among high-risk women by as much as 90 percent. A massive education effort for prevention is needed to focus attention upon these lifesaving measures.

Data in the above chart are from NCI and ACS; age standardized to the 1970 U.S. population.

This article first appeared in healthfactsandfears.com and is reprinted with permission.