Long-Term Responders with No Evidence of Disease Have Better Survival to First-Line HER2 Targeted Therapy for MBC

Evaluation of clinical characteristics of patients with HER2-positive metastatic breast cancer (MBC) with no evidence of disease (NED) versus those with residual disease (RES) experiencing long-term response to first-line HER2-targeted therapy showed that those with NED status have better survival. Premenopausal status and de novo metastatic disease were associated with NED. The findings are published in April 2022 issue of the British Journal of Cancer by Dr. Zachary Veitch of the Department of Medical Oncology and Hematology, St Michael’s Hospital and Department of Medical Oncology and Hematology, Princess Margaret Cancer Centre in Toronto, ON, Canada and colleagues.

The authors wrote in the study background that long-term response to HER2-targeted therapies is not frequent in MBC. In this analysis, patients who received first-line chemotherapy-trastuzumab or taxane-trastuzumab-pertuzumab regimens with response duration at least 2-fold higher than in phase II/III studies were included. Clinical characteristics and radiographic review for NED or RES status was evaluated by Cox-regression or Kaplan–Meier. Characteristics associated with NED were evaluated by logistic regression.

The study team identified 103 patients (4.6%) for this analysis. In multivariate analyses, 46 patients with NED showed improved progression-free (PFS) and overall survival (OS) versus 57 patients with RES (p < 0.001). High 5-year PFS rate (93.2%) and OS (97.4%) were observed in patients with NED relative to 5-year PFS rate (10.6%) and OS (61.3%) in long-term responders with RES.

Furthermore, premenopausal status (p = 0.006), de-novo metastases (p = 0.002), and no palliative radiotherapy (p = 0.01) were associated with NED.

Overall, 6 of 7 (85.7%) patients with NED were alive and disease-free after discontinuing HER2 treatment (≥1 year) versus 1 of 17 long-term responders (5.9%) with RES.

The authors commented that prospective studies of HER2 therapy discontinuation in patients with MBC and NED are warranted.

No funding was procured for this study.

Reference

Veitch Z, Ribnikar D, Tilley D, et al.No evidence of disease versus residual disease in long-term responders to first-line HER2-targeted therapy for metastatic breast cancer. Br J Cancer 2022;126:881–888. DOI: https://doi.org/10.1038/s41416-021-01676-4

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