In a nutshell
This study aimed to investigate the effect of stopping trastuzumab treatment in patients with HER2-positive metastatic breast cancer with radiological complete remission.
This study concluded that trastuzumab may be safely stopped in selected patients with radiological complete remission.
Some background
Trastuzumab (Herceptin) is a targeted therapy called a monoclonal antibody. It is used specifically to treat HER2-positive metastatic breast cancer (MBC). Patients with MBC treated with trastuzumab commonly have lasting tumor responses. These patients achieve durable radiological complete remission (rCR). rCR is the absence of cancer on imaging tests.
It was unknown if patients with durable rCR can safely end trastuzumab treatment.
Methods & findings
This study involved 717 patients with HER2-positive MBC. All patients were treated with first or second-line trastuzumab-based therapy. Patients were followed for an average of 109 months. Prognostic factors for rCR and overall survival (OS) were identified. A prognostic factor is something that can be used to estimate the chance of recovery from a disease or the chance of the disease coming back. Time-to-disease progression (TDP) after achieving rCR for patients who continued and stopped trastuzumab was measured. BC specific survival was also evaluated.
The strongest factor associated with OS was the achievement of rCR. 10% of patients achieved rCR. The ten-year OS estimate for patients who achieved rCR was 52% compared to 7% for patients who did not achieve rCR.
30 patients with rCR stopped trastuzumab. 67% of these patients were alive and in remission after an average of 78 months follow-up since rCR.
40 patients with rCR continued trastuzumab. 33% of these patients were in remission after an average of 68 months of follow-up. The average TDP in this group was 14 months.
The bottom line
This study concluded that trastuzumab may be stopped in selected patients with ongoing rCR. It was also concluded that achieving rCR is the strongest predictor for improved survival in patients with HER2-positive MBC.
The fine print
Further research needed to identify patients in rCR in whom trastuzumab can be safely stopped.
Published By :
Breast Cancer Research and Treatment
Date :
Sep 06, 2019
