One year of adjuvant treatment with the targeted drug Trastuzumab ( Herceptin ) is as good as two years of treatment, for women with HER2-positive early breast cancer who have already received initial treatment with surgery, chemotherapy and radiotherapy as needed, HERA study researchers have found.
The HERA trial, which has been run by the Breast International Group ( BIG ) since 2001, is an international, multi-center, phase III randomized study involving 5102 women with early HER2-positive breast cancer. After finishing primary therapy with surgery, chemotherapy and radiotherapy as indicated, they were randomly assigned to Trastuzumab therapy every 3 weeks for 1 year, 2 years or observation.
As of 12 April 2012, the unadjusted hazard ratio for a woman experiencing disease relapse in the 2-year treatment arm versus the 1-year arm was 0.99 ( p=0.8588 ), Richard Gelber of Harvard Medical School and Dana-Farber Cancer Institute, Boston, MA, USA, reported. The overall survival rate in the two arms was comparable [ HR=1.05; p=0.6333 ) ].
According to Gelber the key message is that 1 year of treatment with Trastuzumab remains the standard of care for HER2-positive early breast cancer patients.
The researchers found that the durable benefit in disease-free survival and overall survival of 1-year Trastuzumab compared to no Trastuzumab that had been reported previously remained stable at 8 years of median follow-up.
This prolonged benefit in disease-free survival and overall survival of 1-year Trastuzumab over no Trastuzumab is remarkably impressive and reassuring to patients. These results have shown that the benefit of adjuvant Trastuzumab remains over time and it is not lost after some years. One year Trastuzumab is a very effective treatment, reducing the risk of disease recurrence and death by one-quarter compared to not using Trastuzumab.
While extending the duration of Trastuzumab administration to 2 years did not significantly improve outcome compared with 1 year Trastuzumab, ongoing trials are testing whether combining Trastuzumab with other anti-HER2 agents ( for example Pertuzumab or Lapatinib ) might further benefit patients with HER2-positive early breast cancer.
Commenting on the data, Christoph Zielinski, at Medical University Vienna, Austria, who was not involved in the study, noted that the progress in the treatment of patients with early breast cancer over-expressing HER2/neu was extremely impressive and particularly successful by the introduction of Trastuzumab as adjuvant treatment. This was administered in the first trials for one year and resulted in a highly significant prolongation of progression-free and overall survival. However, the question lingered whether a prolongation of treatment to two years would result in even better data than the ones obtained before.
The present trial has shown that this is not the case, which strongly supports the correctness of adjuvant treatment duration delivered to patients with HER2/neu over-expressing early breast cancer. Moreover, it has shown that the biology of the disease in the therapeutic interference with growth factor signaling for a period of one year cannot be improved by a longer duration of such treatment. ( Xagena )
Source: European Society for Medical Oncology ( ESCO ) Meeting, 2012