THE ROLE OF MASTECTOMY IN PATIENTS WITH STAGE I-II BREAST-CANCER PRESENTING WITH GROSS MULTIFOCAL OR MULTICENTRIC DISEASE OR DIFFUSE MICROCALCIFICATIONS

Purpose: Women with Stage I-II invasive breast cancer who present with gross multicentric disease or diffuse microcalcifications have a sign ificant risk of breast recurrence when treated with conservative surge ry and radiation. The purpose of this report is to present the results of mastectomy in this group of patients. Methods and Materials: Betwe en 1982 and 1989, 88 patients with clinical Stage I-II breast cancer w ho presented with clinical and mammographic evidence of gross multicen tric disease or diffuse microcalcifications underwent modified radical mastectomy. Median followup was 4 years for the 57 patients with gros s multicentric disease and 5.6 years for 31 patients with diffuse micr ocalcifications. At the time of mastectomy, 42% of patients were found to have positive axillary nodes. Following mastectomy, 15 patients re ceived post mastectomy radiation and 35 patients received adjuvant sys temic chemotherapy. Results: When compared to a group of 1295 patients with unifocal Stage I-II breast cancer, treated with conservative sur gery and radiation during the same time period, patients with gross mu lticentric disease and diffuse microcalcifications had a significantly higher incidence of greater-than-or-equal-to 4 positive nodes, patien ts with gross multicentric disease had a lower incidence of positive r esection margins following mastectomy and patients with diffuse microc alcifications were younger. The 5-year actuarial risk of an isolated l ocal-regional recurrence was 8% for patients with gross multicentric d isease or diffuse microcalcifications and 7% for patients with unifoci al disease. Patients with gross multicentric disease or diffuse microc alcifications and greater-than-or-equal-to 4 positive axillary nodes w ho did not receive post mastectomy radiation had an increased risk for local regional recurrence. There were no significant differences in t he 5-year actuarial overall or relapse-free survival (88% and 73% gros s multicentric disease, 97% and 86% diffuse microcalcifications and 90 % and 79% unifocal disease), freedom from distant metastasis (76% gros s multicentric disease, 90% diffuse microcalcifications, 86% unifocal disease) or incidence of contralateral breast cancer (10% gross multic entric disease, 13% diffuse microcalcifications, 8% unifocal disease) among the three groups. Conclusion: The present study demonstrates no increased risk of local-regional recurrence in patients with gross mul ticentric disease or diffuse microcalcifications undergoing mastectomy in contrast to the increased risk of breast recurrence in patients wi th gross multicentric disease undergoing conservative surgery and radi ation. Indications for post mastectomy radiation include greater-than- or-equal-to 4 positive nodes or close or positive surgical margins. De spite a significantly higher incidence of greater-than-or-equal-to 4 p ositive nodes, patients with gross multicentric disease and diffuse mi crocalcifications have a 5-year actuarial overall and relapse-free sur vival comparable to a group of patients with unifocal disease treated with conservative surgery and radiation.