CHICAGO-Medical contraindications to breast-preserving cancer surgery occur in a minority of patients with early-stage breast cancer when accepted clinical guidelines are appropriately applied, results from a series of more than 400 patients suggest.
CHICAGOMedical contraindications to breast-preserving cancer surgeryoccur in a minority of patients with early-stage breast cancer when acceptedclinical guidelines are appropriately applied, results from a series ofmore than 400 patients suggest.
Contraindications to breast preservation were found in 97 (22.5%) of432 patients whose early-stage breast cancer was diagnosed over a five-yearperiod at Northwestern University Medical Center. The most common contraindicationwas the presence of multifocal or multicentric disease.
However, the incidence and type of contraindications varied by tumorstage, Monica Morrow, MD, said at a general session of the San AntonioBreast Cancer Symposium.
Six prospective, randomized trials have demonstrated the survival equivalenceof breast-conserving surgery and mastectomy. Nonetheless, more than halfof US women diagnosed with early breast cancer continue to have mastectomies,said Dr. Morrow, director of the Lynn Sage Comprehensive Breast Centerat Northwestern.
Several small studies have suggested that contraindications to breastpreservation exist in as many as 40% of women with early-stage breast cancer,she said. The results have helped fuel enthusiasm for neoadjuvant chemotherapyas a means of increasing the rate of breast-conserving surgery.
Dr. Morrow and her colleagues evaluated the incidence of contraindicationsto breast conservation in 432 patients referred for treatment of early-stagebreast cancer from June 1988 to June 1993. There were 96 cases of ductalcarcinoma in situ (DCIS), 167 cases of stage I breast cancer, and 169 casesof stage II cancer.
Joint Committee Criteria for Ruling Out Breast-Conserving Surgery
Multicentric or extensive multifocal disease
Diffusely abnormal mammograms
Large tumor-breast ratio
Prior radiation to the breast field
Social circumstances that prevent the patient from receiving radiation therapy on a regular basis
Contraindications were identified by use of criteria established bythe Joint Committee of the American College of Surgeons, American Collegeof Radiology, and the College of American Pathologists (see table at right). Byuse of those criteria, 335 of the 432 patients qualified for conservation.
Multifocal or multicentric disease was the most common disqualifyingfactor, accounting for 39 of 97 contraindications. Diffusely abnormal mammogramsand a large tumor-breast ratio accounted for 25 contraindications each.
The incidence of contraindications was 33% for DCIS, 10% for stage Ipatients, and 29% for stage II patients. Multifocal/multicentric diseaseaccounted for half the contraindications in DCIS patients. A diffuselyabnormal mammogram was the most common contraindication in stage I patients,accounting for 40% of the contraindications. A large tumor-breast ratioconstituted about 35% of the contraindications in stage II patients, makingit the most common disqualifying factor in that group.
Although positive nodes are not a contraindication to breast conservation,when all women with invasive cancer were considered, node status was afactor in the rate of breast conservation, with 82% of node-negative patientsreceiving conservation versus only 55% of node-positive patients.
Node Status and Tumor Size
This difference disappeared, however, when, to eliminate the influenceof tumor size, only patients with stage II cancer were considered. Amongthese patients, the conservation rate was 52% in node-negative women and55% in those with positive nodes.
Using node status as a criterion for breast-conserving surgery may reflect"a basic misunderstanding of the rationale for breast conservation,which is to improve cosmesis," she said.
Use of breast conservation did not differ by tumor histology or patientage. "Women older than 70 opted for preservation as often as thoseyounger than 40," she said.
Caucasians were significantly more likely to have breast conservation,but the difference was due almost entirely to an increased frequency ofpregnancy, prior radiation, and social contraindications (circumstancesthat prevent the patient from receiving regular radiation) in non-Caucasians.
The investigators also looked at the potential impact of neoadjuvanttherapy on breast preservation rates. They found that only 20 women (lessthan 6% of the total patient population) needed mastectomy because of alarge tumor-breast ratio.
"If, based on the published literature, you assume a complete andpartial response rate of 80% for operable breast cancer patients receivingneoadjuvant chemotherapy," she said, "this means that 16 additionalpatients could have undergone breast preservation, increasing the overallpreservation rate from 77.5% to 81%."
Thus, she concludes that "neoadjuvant therapy is extremely unlikelyto have a major impact on the breast preservation rate in this countryand should be judged on its own merits for decreasing rates of distantrelapse, rather than as a method of improving cosmesis."
'Even at This Late Date . . .'
In response to a question from the audience, Dr. Morrow said that "physicianbias and misunderstanding of contraindications play a much larger rolethan one might anticipate at this late date in breast preservation."
In geographic areas that have very low published rates of breast preservation,she said, "you see that things such as poor prognosis disease, densefibrocystic disease, and tumor location are still being considered contraindicationsto breast preservation, even though there are no supporting data."
In addition, she said, some surveys suggest that many surgeons stillbelieve that mastectomy is a more effective therapy than breast preservation,"and they convey that impression to their patients."