Impact of adjuvant chemotherapy on recurrence-free survival in patients with pT1a/b hormone-negative and HER2-positive breast cancer.

1034 Background: T1ab triple-negative (TN) or Her-2-positive (H2+) breast cancers are reported to pose relatively high risk of relapse, but benefits of adjuvant chemotherapy are uncertain. We studied the impact of chemotherapy on recurrence-free survival in this group. Methods: Records of all consecutive cases diagnosed in Brown-affiliated centers in 2000 - 2010 were reviewed. Factors influencing chemotherapy decision were studied with logistic regression, and recurrence-free interval (RFI) with a Cox proportional hazard model and Kaplan-Meier estimator. Results: Among 1415 screened T1a/b N0 cases, 161 were eligible (57 TN; 104 HER2+), with a median age of 57 years; 66% tumors were T1b. 20% of patients underwent mastectomy, 76% received radiation and 30% hormonal therapy. Adjuvant chemotherapy was recommended in 53% of cases. Younger age (p<10-6), stage T1b (p<10-5), high grade (p=0.001), HER2+/ERPR- status (p=0.017) and diagnosis after 2006 (p=0.007) were significantly predictive of the medical oncology ...