by Marian Tompson President, La Leche League Internatnonal

Because fear of breast cancer has so blighted the lives of women as they examine their breasts each month, this is an issue I can deal with comfortably only in terms of prevention, in this instance, the protection offered by breastfeeding. Now I admit this theory is a controversial one: Recent studies by McMahon and others claim there is little or no difference in the breast cancer rate of women who breastfed and those who did not. But I question such studies which make no differentiation between women who practice total and unre- stricted breastfeeding and those who follow a more limited breastfeeding pattern. I suspect the results would be different if breastfeeders were identified as only those women who nurse totally without bottles or supplements for the first six months and then nurse beyond that for prolonged periods of time.

In places where such total and longterm breastfeeding is common, breast cancer is uncommon. Reporting in 1969 on a group of Canadian Eskimos who had been surveyed for l5 years, Otto Schaefer, M.D. said that during all that time only one case of breast cancer was discovered in this population that grew from 9,000 to l3,000. In populations where breast cancer was very low, but is now increasing, Dr. Schaefer says the common contributing factor seems to be either a decrease in the duration of breastfeeding or its complete elimination. In the United States, in a 1964 study of breast cancer patients at Roswell Park Institute in New York, Levin found that breastfeeding for l7 months decreased the risk of breast cancer. After a total of 36 months lacta- tion, this risk was even more markedly reduced. And the 1977 report by Ing of the higher incidence of breast cancer on the unsuckled left breast of the Tanka boat women (who traditionally breastfeed from the right breast) seems to further support the concept of protection through breastfeeding.

But what about the baby? I have known a small number of women who have breastfed infants after having had a mastectomy and some who have had mastectomies after having breastfed. Could they transmit the disease to their babies? This question surfaced several years ago with reports of a discovery by Dan H. Moore, Ph.D., of a mammary tumor factor in the milk of certain strains of mice. However, in a talk given at a symposium on breastfeeding at the University of Pittsburgh last November, Dr. Moore admitted that not only had this milk—transmitted influence not been demonstrated in humans, but he felt there were major reasons to believe there cannot be a mammary cancer—causing agent in human milk. "The decrease in breastfeeding in the United States and other Western countries," Dr. Moore explained, "has not been accompanied by a decrease in breast cancer." He went on to cite studies by Tokuhato (1969) and Anderson (l975) which showed no difference in the breast cancer incidence in daughters who were breastfed even when the breastfeeding mothers were later found to have cancer.

So while science continues to try to identify causes, I take some comfort in the rationale offered by Herbert Ratner, M.D., former director of the Oak Park Illinois Health Department, that the more one deviates from the natural order of things which are responsible for the preserva- tion and thriving of the species, the more one can expect to find pathological processes developing. One of the risks with breast cancer comes from disrupting a reproductive process which begins with conception and ends with weaning. Or as Hippocrates put it succinctly in 5 B.C., "Use leads to health and disuse to disease."