- The risk for late relapse occurring 5-10 years after diagnosis is only 3%-6% among trastuzumab-treated patients with human epidermal growth factor receptor 2 (HER2+) breast cancer (BCa).
- Similar late benefit was obtained with patients with hormone receptor (HR)+ and HR− disease.
Why this matters
- This is the first study to quantify the risk for late relapse in this population.
- Combined analysis of 2 randomized controlled clinical trials (North Central Cancer Treatment Group N9831 [Alliance] and NRG Oncology/NSABP B-31) in which 3177 patients with HER2+ BCa were given adjuvant chemotherapy alone (12 weeks) or trastuzumab (n=52 weeks).
- Funding: NIH; Genentech; others.
- Overall, HR+ (vs HR−) HER2+ cases, regardless of treatment type, had improved recurrence-free survival (RFS) during the first 5 years (HR, 0.65; P<.001>
- Trastuzumab-treated patients had lower cumulative hazard for RFS in patients with HR+ (vs HR+−) disease during the first 5 years (10.96% vs 17.48%; HR, 0.60; P<.001>
- During years 5-10 after trastuzumab treatment, no difference in RFS benefit was found by HR status (HR, 1.32; P=.12).
- Although risk for recurrence was low for HR+ HER2+ disease, it was lowest for patients without lymph node involvement (3.23%) and slightly higher (6.39%) in patients with 1-3 positive lymph nodes.
- Lack of longer follow-up.