Chemotherapy duration and patient-reported outcomes in HER2-positive early breast cancer: Results from the TRAIN-3...

Anti-HER2 based (neo)adjuvant chemotherapy has substantially improved outcomes for patients with stage II-III HER2-positive breast cancer but often leads to long-term toxicities that impair survivors' health-related quality of life (HRQOL). The TRAIN-3 study demonstrated that shortening neoadjuvant chemotherapy based on early complete response on breast MRI preserves efficacy. The impact of chemotherapy duration on HRQOL remains unclear. Here, we report the results from the pre-planned HRQOL analyses.

HRQOL was assessed at baseline, and at 6, 12 and 24 months using the EORTC QLQ-C30 and QLQ-BR45 questionnaires. Patients with baseline and at least one follow-up assessment were included for this analysis.

Ninety patients were evaluable: 29 (32%) received 1-3 cycles, 26 (29%) received 4-6 cycles, and 35 (39%) received 7-9 cycles of neoadjuvant chemotherapy. Patients receiving 1-3 cycles reported consistently better preservation of physical and role functioning, less fatigue, and lower neuropathy scores compared to those receiving longer chemotherapy. At 24 months, clinically meaningful deterioration in global health status was observed in 26%, 55% and 46% of patients in the 1-3, 4-6 and 7-9 cycle groups, respectively. Greater neuropathy was associated with worse global HRQOL at both 12 and 24 months.

MRI-guided shorter neoadjuvant chemotherapy duration is associated with less pronounced declines and better long-term preservation of HRQOL in patients with early HER2-positive breast cancer. These findings support MRI-guided treatment de-escalation as a strategy to reduce survivorship burden without compromising efficacy.