TRASTUZUMAB FOR BREAST CANCER
The clinical effectiveness of trastuzumab for breast cancer: a systematic review
Background
There is evidence that the over-expression of the product of the HER2 oncogene is an important prognostic factor in metastatic breast cancer, indicating a more aggressive form of the disease with a more rapid progression and shortened survival time. Trastuzumab (Herceptin), a recombinant humanised monoclonal antibody that specifically targets the epidermal growth factor receptor 2 (HER2) protein, is a relatively new anti-cancer agent that may be beneficial in a specific group of patients who are identified as having tumours that strongly over-express HER2. The objective of this review was to evaluate the effectiveness of trastuzumab in the management of breast cancer.Findings
Trastuzumab when used in combination with chemotherapy seemed to be more effective than chemotherapy alone for the treatment of metastatic breast cancer over-expressing HER2 at level 3+ in individuals who had not received prior treatment for metastatic breast cancer. However, it seemed to be associated with congestive heart failure, particularly in patients that received anthracycline-based chemotherapy.
Trastuzumab monotherapy when used as second-line or subsequent therapy for the treatment of metastatic breast cancer over-expressing HER2 at level 3+ appeared to have some anti-tumour effects in terms of overall tumour response based on non-comparative studies (which provide relatively weak evidence) of moderate quality.
Conducted by: R Lewis1, A-M Bagnall1, C Forbes1, E Shirran1, S Duffy1, J Kleijnen1, R Riemsma1, G ter Riet1