Adjuvant Trastuzumab for HER2-positive Breast Cancer: 1-year Is Optimal Therapy Duration

Administering adjuvant trastuzumab for 1 year yields superior survival outcomes to other treatment durations among patients with HER2-positive breast cancer, according to research being presented at the 2017 San Antonio Breast Cancer Symposium.¹

As the 1-year adjuvant trastuzumab duration was chosen arbitrarily, several non-inferiority studies compared shorter durations with 1-year therapy to identify the optimal regimen. The results of these studies were, however, inconsistent.

For this meta-analysis, the authors pooled results from 3 of these studies, which involved 5114 patients with HER2-positive disease, to determine which adjuvant trastuzumab duration yielded the optimal overall survival (OS), disease-free survival (DFS), and rate of cardiac events.

Compared with shorter durations, 1-year adjuvant trastuzumab carried a hazard ratio (HR) for OS of .78 (P = .04) and an HR for DFS of .80 (P = .004). DFS was superior for the 1-year duration regardless of estrogen receptor–status (HR for positive, .82; HR for negative, .78) and nodal status (HR for positive, .76; HR for negative, .87).

Patients who received adjuvant therapy for 1 year were, however, more than 2.5 times as likely to have cardiac events (odds ratio, 2.65; P < .001).

The authors concluded that “analyses of [randomized controlled trials] demonstrated a significant improvement in overall, and disease-free survivals with 1 year of adjuvant trastuzumab compared to shorter durations for adjuvant treatment of HER-2 positive breast cancer. One year of trastuzumab should remain as the standard of care.”

Read more of Cancer Therapy Advisor‘s coverage of the San Antonio Breast Cancer Symposium (SABCS) 2017 meeting by visiting the conference page.

Reference

1. Niraula S, Gyawali B. Duration of adjuvant trastuzumab in HER-2 positive breast cancer: Pooled results of overall, and disease-free survivals from meta-analyses of randomized controlled trials. Poster presentation at: 2017 San Antonio Breast Cancer Symposium; December 5-9, 2017; San Antonio, TX.