Stanford Report, May 2, 2001
|Study shows surgery not
always necessary in treating breast cancer
BY GREG MILLER
Surgically removing tumors doesn't necessarily increase the survival rate of women with locally advanced breast cancer, according to a study by Stanford University Medical Center researchers -- a finding that challenges widely held notions about treating this type of cancer.
Locally advanced breast cancer, or LABC, is an extremely serious condition. Patients with LABC have large tumors (greater than 5 centimeters in diameter) that extend from the breast into the chest wall or skin, and show evidence that the cancer has spread to lymph nodes under the arm. The major risks these patients face are failure to control the tumor at its origin, known as local control, and the possible spread of cancer cells to other sites in the body.
Fortunately, few women have this stage of cancer at the time of diagnosis, said Frank Stockdale, MD, PhD, the Maureen Lyles D'Ambrogio Professor of Medicine and senior author of the study.
The study was published in the March/April issue of The Breast Journal. Other co-authors are Anne M. Favret, postdoctoral fellow; Robert W. Carlson, MD, professor of medicine; Donald R. Goffinet, MD, professor of radiation oncology; Stefanie S. Jeffrey, MD, assistant professor of surgical oncology; and Frederick M. Dirbas, MD, assistant professor of surgery.
Stockdale noted that while a small percentage of breast-cancer patients reach the LABC stage, the strategies used in managing LABC often provide physicians with insights about treating the more common forms of breast cancer.
Standard treatment for LABC is chemotherapy followed by surgical removal of the breast, Stockdale said. In a typical treatment scheme the patient "would receive chemotherapy followed by modified radical mastectomy, which would be followed by radiation and often more chemotherapy," he said.
The assumption behind this approach is that surgically removing the cancerous tissue -- either through a radical mastectomy (surgical removal of the breast) or a lumpectomy (surgical removal of the tumor but not the surrounding tissue) -- increases local control on the chest wall and improves the patient's odds of survival. However, the study indicates this rationale may be misguided, Stockdale said.
For the study, Stockdale and his colleagues followed the progress of a group of LABC patients at Stanford Hospital and Clinics who did not have their tumors surgically removed. These women received intensive chemotherapy followed by carefully planned radiation treatment of the affected breast, followed by additional chemotherapy and, in many cases, hormonal treatment.
Women in the study were allowed to undergo a surgical procedure if they wished, either for personal reasons or because their tumor was responding poorly to the combined chemotherapy/radiation/hormone treatment. Twenty women from the original group of 64 elected to have surgery.
After the treatment, the researchers conducted follow-up exams over several years to evaluate the women for signs of recurrent cancer.
Of the women who received the combined treatment and did not undergo surgery, 68 percent had no evidence of recurrent cancer after a median follow-up period of 51 months. The five-year survival rate for this group was 75 percent. These numbers were comparable to recurrence and survival rates reported in the literature for women treated surgically, and were no different from the rates for the 20 women who underwent either mastectomies or lumpectomies.
Stockdale said his group also noted that there was no disadvantage for control of the local tumor when surgery was avoided -- those without surgery experienced local control of more than 85 percent, a figure comparable to the rate for the women who had the tissue and/or breast surgically removed.
Stockdale said the findings suggest that, as with patients in the early stages of breast cancer, surgical intervention may not improve the overall outcome for women with LABC. "There is a misconception about breast cancer -- that mastectomy must always be a part of the cure," he said.
"What influences survival is stopping the cancer from reappearing locally or in other organs," he said. "Today this means a combination of differing modalities of treatment."
Weigh the outcomes
In past treatments of LABC, Stockdale said there was too much emphasis on removing the cancer in the breast. However, he noted that a mastectomy is not always feasible with some patients and -- based on the study results -- may be unnecessary.
Stockdale said that while surgical removal of the tissue makes it possible to study cancer at molecular and cellular levels for clues about treatment options, physicians must weigh that against performing surgery on patients whose outcome may not be improved by the procedure.
Based on the results of the study, Stockdale predicted treatment strategies for breast-cancer patients will continue to change, with more emphasis placed on combined approaches.
the future, breast-cancer patients -- both those in the early
stages and those with LABC -- will receive chemotherapy and
hormonal therapies that are combined with improved forms of
radiotherapy, and increasingly less surgery," he said.