ABSTRACT
Introduction: Human epidermal growth factor receptor 2 (HER2) expression is considered an unfavourable prognostic factor in early breast cancer when the patients are not treated with HER2-targeted therapy. However, the long-term prognostic importance of HER2 expression in small (≤1 cm, stage pT1a-b), node-negative HER2* breast cancer is still incompletely known. Methods: A retrospective analysis was performed based on a prospectively collected database including patients with pT1 breast cancer operated at the Helsinki University Hospital, Finland, between March 2000 and April 2006. In this database, 44 patients with pT1a-bN0M0, HER2* cancer, not treated with adjuvant anti-HER2-targeted therapy (the HER2* group) and 291 pT1a-bN0M0, hormone receptor-positive, HER2-negative cancers (the ER*/HER2- group) were identified and included in the study. Survival outcomes were analysed using the Kaplan-Meier method. Results: The median follow-up time was 9.7 years after primary breast surgery. Ten-year distant disease-free survival (DDFS) was 84.0% in the HER2* group and 98.2% in the ER*/HER2- group (p < 0.001). Ten-year overall survival was only 78.5% in the HER2* group, but 91.7% in the ER*/HER2- group (p = 0.09). Conclusions: Cancer HER2 status is strongly associated with unfavourable DDFS during the first decade of follow-up in patients with small (pT1a-bN0M0) breast cancer when adjuvant anti-HER2-targeted treatment is not administered.
ABSTRACT
BACKGROUND: The prognostic significance of isolated tumour cells (ITCs) in the sentinel nodes (SNs) is controversial in early breast cancer, and some centres have abandoned immunohistochemistry to detect ITCs. METHODS: Patients with unilateral pT1N0 breast cancer, operated between February 2001 and August 2005 at a university hospital were included in this prospective, population-based cohort study. Survival of 936 patients with or without isolated tumour cells (ITC) in their SNs were compared with the log-rank test and Cox regression analysis. RESULTS: Eight hundred sixty one (92.0%) patients were ITC-negative (pN0i-) and 75 (8.0%) ITC-positive (pN0i+). Patients with ITC-positive cancer received more frequently adjuvant systemic therapies than those with ITC-negative cancer. The median follow-up time was 9.5 years. Ten-year distant disease-free survival was 95.3% in the pN0i- group and 88.8% in the pN0i+ group (P = 0.013). ITCs were an independent prognostic factor in a Cox regression model (HR = 2.34, 95% CI 1.09-5.04; P = 0.029), together with tumour Ki-67 proliferation index and diameter. ITCs were associated with unfavourable overall survival (P = 0.005) and breast cancer-specific survival (P = 0.001). CONCLUSIONS: We conclude that presence of ITCs in the SNs is an adverse prognostic factor in early small node-negative breast cancer, and may be considered in the decision-making for adjuvant therapy.
