Durable complete response in HER2-positive breast cancer: a multicenter retrospective analysis

Area of Science:

• Oncology
• Medical Research

Background:

• Advanced and metastatic HER2-positive breast cancer is generally considered incurable.
• A subset of patients with HER2-positive metastatic breast cancer experience prolonged remission with anti-HER2 therapies.

Purpose of the Study:

• To investigate the hypothesis that HER2-positive metastatic breast cancer may be curable in some cases.
• To assess the long-term outcomes of patients with a durable response to trastuzumab therapy.

Main Methods:

• Retrospective analysis of 108 patients with HER2-positive metastatic breast cancer treated with trastuzumab for over 2 years as first-line therapy.
• Data collected from 19 Japanese institutions between April 2001 and December 2014.
• Median follow-up of 7.7 years.

Main Results:

• Median progression-free survival was 11.2 years, with over 80% of patients alive at 10 years.
• 40.7% experienced disease progression, and 12% died.
• 57 patients achieved a complete response; 27 interrupted trastuzumab, with only 4 experiencing progression after interruption.

Conclusions:

• Some patients achieved no evidence of disease after discontinuing trastuzumab.
• Cautious exploration of discontinuing maintenance trastuzumab in this population is recommended.
• Further investigation via a global randomized trial is needed.