Real-life study of 7-year survival in patients treated with trastuzumab for HER2+early breast cancer

Background and rationale > Despite improved prognosis of HERZ since the introduction of trastuzumab in the adjuvant setting of early breast cancer, disease recurrences still occur, particularly in certain patient subgroups. The objective of this real-life study conducted in France is to evaluate after 7 years, disease-free survival (DFS) and distant metastatic-free survival (MFS). Methods > This was a multi-center, retrospective, observational study assessing early HER2+ breast cancer patients diagnosed between January 1st, 2009 and December 31st, 2010 treated with adjuvant trastuzumab. DES and MFS were evaluated within subgroups according to hormonal and nodal status. Results > Based on 2311 patients documented, according to nodal status, the 7-year DFS rate was significantly higher for N- than for N+ patients [87.2% vs. 66.8%; P < 0.001], and the 7-year MFS rate [94.7% for N- vs. 74.9% for Ni; P < 0.001]. According to hormonal status, the 7-year DFS rate was significantly higher for HR+ than for HR patients [80.5% vs. 69.2%; P < 0.001], and the 7-year MFS rate [88.0% for HR+ vs. 77.7% HR-]. Conclusions > Despite the overall improvement in the prognosis of early HER2+ breast cancers, patients in the N+ and RH- subgroups hove a high risk of metastatic recurrence at seven years, justifying the search for more effective treatment alternatives.