ASCO--Fewer than half of women with early-stage breast cancer are treated with breast-conserving lumpectomy, even though up to 75% are eligible. Almost one-quarter of those who have lumpectomy are not given radiotherapy to improve local control.
Both problems are largely the result of surgeons failure to follow the joint guidelines of the American College of Surgeons, American College of Radiology, and College of American Pathologists, Monica Morrow, MD, said in her ASCO presentation of a study performed by the American College of Surgeons and the American College of Radiology.
Dr. Morrow is professor of surgery and director of the Clinical Breast Cancer Program at Northwestern Universitys Lynn Sage Breast Program.
The guidelines for breast-conserving therapy were developed in 1992 and have been widely disseminated. This study to evaluate guidelines adherence included data on 17,931 women with stage I or II breast cancer treated in 1994. Among its main findings:
Only 7,914 (44.1%) had breast-conserving therapy.
About 47% of patients who received breast-conserving therapy were under age 60, compared with 41% of mastectomy patients (P < .0001).
About 54% of clinical stage I patients had breast-conserving therapy, compared with 32% of clinical stage II patients and 39% of patients with no clinical stage data (P < .0001).
About 53% of women with T1 tumors had breast-conserving therapy vs 33% of those with T2 tumors (P < .0001).
Some 47% of node-negative patients had breast-conserving therapy vs 32% of node-positive patients (P < .0001).
According to the guidelines, the only contraindications to lumpectomy plus radiotherapy in early-stage breast cancer are large tumor size, small breast size in comparison to tumor size, early pregnancy, and multiple tumors in various sites. Older age, prognosis, and tumor type are not indications for mastectomy.
Dr. Morrows data show that surgeons are less likely to do lumpectomies for older patients and are more likely to do mastectomies if patients have stage II disease, T2 size tumors, or positive nodes. For example, a 70-year-old woman was one-third less likely to be treated with breast-conserving therapy than a younger woman with similar disease.
"These data indicate that physicians still believe that if you have poorer-prognosis breast cancer, you are better off being treated with mastectomy," Dr. Morrow commented. Patients with favorable histologies (tubular, mucinous, intracystic) were more likely to have had breast conservation than those with other histologies (P < .0001).
Perhaps more important, radiotherapy was given to only 78.6% of patients treated with lumpectomy. "Of 1,155 patients not receiving radiotherapy, surgical failure to refer for radiotherapy accounted for 51.1%, and patient refusal for 15% of cases," Dr. Morrow said.
Surgeons continue to reserve breast-conserving therapy primarily for patients with favorable breast cancer, in spite of guidelines and data from randomized trials indicating that age, prognosis, and tumor type should not be used as selection criteria for local therapy. "This misunderstanding is a major factor responsible for low national rates of breast-conserving therapy," Dr. Morrow said.