Six-year follow-up of patients with microinvasive, tla, and T1b breast carcinoma

Background: Management of patients with breast cancers less than or equal t o 1 cm remains controversial, Reports of infrequent nodal metastases in tum ors less than or equal to 5 mm has led to suggestions that axillary dissect ion should be selective, and that tumor characteristics should guide adjuva nt therapy. Methods: A retrospective review of 290 patients with breast cancer 1 cm in size or smaller from 1989 to 1991 was done. Distant disease-free survival ( DDFS) was the primary outcome measure. Results: There were 95 T1a (less than or equal to 5 mm) and 196 T1b (6-10 m m) cancers. Nodal metastases were found in 8 T1a and 26 T1b tumors. Larger size, poorer differentiation, and lymphovascular invasion (LVI) were associ ated with more nodal metastases, but none of these trends reached statistic al significance. The 6-year DDFS was 93% for node-negative and 87% for node -positive patients (P = .02). Overall, breast cancers with poorer different iation and LVI trended toward a poorer outcome. For patients with node-nega tive tumors, LVI was associated with a poorer outcome (P = .03). The size o f the primary tumor was not predictive of outcome. There were no nodal meta stases or recurrences in the is patients with microinvasive breast cancer. Conclusions: Lymph node status is the major determinant of outcome in breas t cancers 1 cm in size or smaller. Accurate axillary assessment remains cru cial in management of small breast cancer.