Of all the issues discussed here none has generated more controversy among physicians and patients than the treatment of breast cancer. New knowledge about the way breast cancer develops has prompted a reevaluation of treatments. For example, some breast cancers spread so quickly that there are distant metastases before the local tumor is detectable by any of our present means.
Surgery remains the most commonly used local treatment and physicians agree that in most cases surgery may offer the best hope for cure, although there are instances in which radiation therapy can produce equally good results. (The different types of operation for breast cancer are illustrated in.
Radiation therapy is also a local treatment, intended to kill cancer cells that have not been surgically removed and to halt their spread to other parts of the body. Neither surgery nor radiation therapy will eradicate those cancer cells that have escaped from the breast through the lymph or blood vessels.
The body’s immune system will, for a time, kill or wall off most of these free-floating cells. But if the primary tumor is not eliminated, the number of transported cells will become too large for the body’s natural immune defenses, and metastases will begin to grow. Thus the principle of local treatment, whether by surgery or radiation therapy or both, is to eliminate the primary source of the cancer cells before their dissemination becomes too great. The controversy revolves around how little or how much breast tissue needs to be removed or treated to ensure that the primary cancer has been eliminated.
Surgical Treatment of Breast Cancer
The evolution of current surgical treatments of breast cancer began shortly before the turn of the century, when the disease was virtually incurable. At that time Dr. William Halsted, a Baltimore surgeon, felt that the poor results stemmed from the fact that the operations then used were inadequate. He devised the operation that still bears his name the Halsted radical mastectomy, in which the entire breast, underlying muscles, and the axillary lymph nodes all were removed. His operation was based on the idea that the cancer extended widely within the breast and spread initially through the muscles into the axillary lymph nodes. The cancers treated in his early operations were large, but he demonstrated that through extensive surgery, a cure for breast cancer might be possible.
Several concurrent developments led to a modification of the Halsted procedure during the 1930s. As women became more educated about the warning signs of breast cancer, they began seeing their doctors while the disease was in its early stages. Researchers found that breast cancer seldom extended into the underlying chest muscles and that recurrence in this area was unusual. Radiation equipment and therapy improved, adding another dimension to local treatment.
An English surgeon, Dr. P. H. Patey, developed a modified radical mastectomy in which the breast and axillary lymph nodes were removed but the underlying muscle was left intact. This operation is not as disfiguring as the Halsted procedure, which left a depression that extended to the collarbone, and it also preserves much of the range of arm motion. The modified radical mastectomy gradually gained worldwide acceptance as time demonstrated that its cure rate was about the same as for the Halsted operation. In the United States a marked increase in the number of modified radical mastectomies began about 1970, and by 1977 a survey by the American College of Surgeons showed that almost 70 percent of breast cancers were being treated by this operation. It should be noted, however, that cancers deep within the breast that invade the chest wall muscle require the more radical procedure.
Another operation that has increased in popularity in recent decades is the simple mastectomy, in which the entire breast is removed, but not the muscles or axillary lymph nodes. Also referred to as a total or complete mastectomy, this operation is favored by doctors who believe in leaving the lymph nodes to help fight residual cancer cells in the area. A few lymph nodes may be removed to see if they have cancer cells in them. It is used for very early cancers carcinoma in situ and Stages I and II—and for patients who are not well enough to withstand more extensive surgery. It may be followed by radiation therapy, except for in situ carcinomas or early Stage I cancers. Simple mastectomy also may be performed in some instances to relieve the discomfort of patients whose breast cancers have ulcerated, even when there are metastases elsewhere in the body.
Over the last fifteen years there has been considerable controversy over whether a simple mastectomy gives a woman as good a chance of survival as the more extensive radical or modified radical procedures. In 1971 the National Surgical Adjuvant Breast Project undertook a major study to try to resolve the question. A total of 1,665 women at thirty-four institutions in the United States and Canada participated in the study. They were randomly assigned to be treated by one of three modalities: radical mastectomy, total or simple mastectomy without removal of the axillary nodes but with irradiation, or total mastectomy without radiation therapy. In the latter group, the axillary nodes were removed only if some were found to contain cancer. These women were then followed for ten years and results of the study were published in early 1985.
The researchers found that 57 percent of the women whose cancers were confined to the breast (no spread to the axillary nodes) were alive with no evidence of cancer at the end of ten years, regardless of the method of treatment. Similarly, no difference in survival was noted among the various treatment groups for women whose cancers had spread to the lymph nodes— 38 percent were alive at the end often years regardless of the approach to treatment. The researchers concluded that there was no advantage to the more extensive surgery or regional radiation therapy so far as long-term survival was concerned.