Recently there have been reports of three studies that show a benefit from the use of a drug named trastuzumab (Herceptin®) in the treatment of early breast cancers that over express (have too much of) a gene called HER2. Most breast cancer do not have too much of this gene and for those cancers these results do not change any of our treatment recommendations. However, for the 15% of breast cancer that do have too much of this gene, there may be a benefit of treatment with Herceptin depending on other factors related to the breast tumour itself and some factors related to a woman's general health.
What does this mean for breast cancer patients? If you were diagnosed and treated for an early breast cancers in the last year, your original tumour may have already been tested at the time of the initial pathology assessment for HER2. If it was, your oncologist will know the results and can discuss with you if you would benefit from further therapy. If your tumour was not tested for HER2, it can be tested now in the central laboratory that is specializing in this test. You should get in touch with your oncologist to find out if your tumour was tested.
Not all women will benefit from treatment with Herceptin:
- If the tumour does not overexpress HER2, this treatment will not benefit you. If your tumour was very small, there may not be a benefit from treatment.
- If you did not receive chemotherapy for your newly diagnosed breast cancer you are not a candidate for Herceptin.
- The treatment has side effects including a potential to damage the heart. Before any treatment with Herceptin we need to test and see if your heart is normal, to avoid causing damage.
- If you were treated more than a year ago, there is no evidence that giving Herceptin now will benefit you and a decision will need to be made based on when your chemotherapy finished.
- If you have been treated with chemotherapy within the last year and you are found to be eligible the treatment is given by intravenous injection once every three weeks for one year.
Your oncologist can discuss with you what your individual benefit may be and what the risks may be. As these studies were just reported there is not a lot of information yet on potential long term risks. There is a known risk of some heart toxicity in a minority of women and all patients on Herceptin are monitored for this.
Please contact your oncologist directly to discuss this new policy and how it affects you individually.
Karen Gelmon
Chair Provincial Breast Tumour Group |
Susan Ellard Breast
Systemic Policy |
Susan O'Reilly Provincial Systemic Program Leader |