T1a breast carcinoma and the role of axillary dissection

Hypothesis Axillary dissection (ad) does not affect recurrence or survival in t1a breast cancer. Design Cohort study comparing patients who underwent ad and those who did not. Setting Provincial cancer agency. Patients Six hundred ninety-one women with pathologically diagnosed t1a tumors. Main outcome measures Rates of axillary metastases stratified according to grade and lymphovascular and/or neural invasion, rates of relapse, and disease-specific survival. Results Grade 1, 2, and 3 tumors without lymphovascular and/or neural invasion had axillary nodal involvement rates of 0.7%, 7%, and 7.8% of patients, respectively; with lymphovascular and/or neural invasion, axillary nodes were involved in 9.1%, 39.3%, and 44.4%, respectively. no statistically significant differences were found between the cohorts in relapse rates ( P = .70) or survival ( P = .84). Conclusion Higher tumor grade and lymphovascular and/or neural invasion increased the rate of nodal metastases in t1a tumors, but ad did not improve relapse rates or breast cancer–specific survival.