Prognostic value of positive human epidermal growth factor receptor 2 status and negative hormone status in patients with T1a/T1b, lymph node-negative breast cancer.

Background: The objective of this study was to evaluate prognostic factors of local and distant recurrence in patients diagnosed with T1a and T1b, lymph node-negative breast carcinoma (BC) with emphasis on human epidermal growth factor receptor 2 (HER2) status.

Methods: The authors reviewed 704 women with T1aT1bN0M0 BC who received treatment at the Radiation-Oncology Center of Florence University between November 2002 and December 2008. Patients with ductal carcinoma in situ or recurrent BC at presentation and patients who received adjuvant chemotherapy were excluded from the analysis.

Results: In total, 75 patients had HER2-positive BC (10.7%). At a mean follow-up of 4.9 years (standard deviation, 2.6 years; range, 0.5-10.8 years), 19 events were identified, including 10 distant recurrences. Patients with HER2-positive BC had worse distant recurrence-free survival (DRFS) than patients with HER2-negative BC (hazard ratio, 3.66; 95% confidence interval, 0.94-14.69; P = .045). Negative hormone receptor (HR) status was associated significantly with worse DRFS (hazard ratio, 0.26; 95% confidence interval, 0.07-0.93; P = .026). In multivariate analysis, younger age was the only significant risk factor for an event of recurrence (hazard ratio, 0.61;95% confidence interval, 0.20-1.82; P = .029).

Conclusions: The current results indicated that patients with T1a/T1b, lymph node-negative BC have a low risk of distant and local recurrence, but younger age is a significant risk factor for events occurrence. Young women with HER2-positive and HR-negative status have a significant risk of distant recurrence and should be considered for future clinical trials with anti-HER2 adjuvant therapy.