The following is a summary of “Nine-Week Versus One-Year Trastuzumab for Early Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer: 10-Year Update of the ShortHER Phase III Randomized Trial,” published in the November 2023 issue of Oncology by Conte, et al.

In the final analysis of the phase III ShortHER trial, a comparison of 9 weeks versus 1 year of adjuvant trastuzumab with chemotherapy was conducted in patients with human epidermal growth factor receptor 2–positive (HER2+) early breast cancer (BC). 

The study randomized women with HER2+ BC into anthracycline-taxane combinations plus 1-year trastuzumab (long arm) or 9-week trastuzumab (short arm). The second coprimary endpoint, overall survival (OS), was reported, along with updated disease-free survival (DFS), and outcomes based on hormone receptor status, age, and nodal status.

With a median follow-up of 9 years, the 10-year DFS rates were 77% in the long arm and 78% in the short arm. The 10-year OS rates were 89% in the long arm and 88% in the short arm. Analyzing DFS rates according to nodal status, N0 showed 81% in the long arm versus 85% in the short arm, N1-3 showed 77% versus 79%, and N4+ showed 63% versus 53%. OS rates according to nodal status were N0: 89% versus 95%, N1-3: 92% versus 89%, and N4+: 84% versus 64%. The updated ShortHER trial analysis indicates that 1-year trastuzumab remains the standard treatment for HER2+ early BC, with no claim of noninferiority. 

However, the numerical differences for low or intermediate risk (N0/N1-3) patients are negligible, while those with N4+ show a clear benefit with 1-year trastuzumab.

Source: ascopubs.org/doi/full/10.1200/JCO.23.00790