Maychai Brown

At its biennial meeting in Montreal during the weekend of May 6th, the Canadian Breast Cancer Research Alliance (CBCRA) staged an Oxford debate, "This House Believes That Cure is Better Than Prevention".

Representatives of BCAM attended, anticipating a significant exchange of ideas that might influence funding decisions by the CBCRA — the largest funder of breast cancer research in Canada and recipient of funds from such sources as the mammoth Canadian Breast Cancer Foundation, the Avon Flame Foundation and the Government of Canada — among others.

The line-up of debaters was impressive. Speaking in support of "cure" were Dr. Kathleen Pritchard of the Toronto-Sunnybrook Regional Cancer Centre and Dr. Alexander Paterson, Chair of the Alberta Breast Cancer Program. On the side of "prevention" were Dr. Norman Wolmark, Chair of the National Surgical Adjuvant Breast and Bowel Project, and Dr. Karen Gelmon of the B.C. Cancer Agency.

What was not anticipated was that three of the four debaters interpret "prevention" as "chemoprevention" and that much of the debate focused on whether or not more resources should be allocated to development of drugs such as selective estrogen receptor modulators, or SERMs (i.e.,.tamoxifen and raloxifene) rather than the quest for primary prevention.

For those of us who would like to see a serious effort to isolate and eliminate causes of breast cancer, this was discouraging. However, once we realized that "prevention" was not going to include environmental effects, we were forced to agree with the position taken by Drs. Pritchard and Paterson against widespread use of chemoprevention. From them we heard the magic words, "First, do no harm", "Much more research is needed into the causes of breast cancer", "Chemopreven-tion risks side effects for those who do not need to be treated", and "If we had a perfect prevention technique and a perfect cure, we'd choose the prevention each time."

The last speaker, Dr. Karen Gelmon, opened the debate to a broader interpretation of prevention, contributing interesting and sometimes controversial aspects of the debate. She illustrated the causes of breast cancer with three circles — one for environmental causes, one for genetic factors, and a third for the many possible interactions between a woman's individual physiology and the environment.

Citing the history of tuberculosis as a crisis in public health in which incidence declined before the cause was ascertained, Dr. Gelmon suggested the interesting possibility that the incidence of breast cancer might diminish as the unintentional result of betterr public health and environmental policies. While she did not mention the precautionary principle as such, it could be inferred.

Dr. Gelmon proposed that lifestyle changes in adolescent girls might be crucial in preventing the disease, noting the links between early tobacco use and later development of the disease. Still focusing on adolescence, she suggested that postponing menarche (onset of menstruation) might prevent breast cancer. While she did not suggest how this might be accomplished, one might infer that new forms of chemoprevention are imminent — with all the attendant drawbacks.

The most telling point of Dr. Gelmon's argument was the issue of dollars and cents. With the astronomical costs of treating patients with such drugs as Herceptin and Avastin, she asked, "Can the public health system afford NOT to take a preventative approach?" It is ironic that the end result of the huge investment into finding a cure may be to push for primary prevention. Let's hope that the CBCRA funders were paying attention.