Herceptin (trastuzumab) is an antibody administered intravenously to treat some breast cancers. It is manufactured in the U.S. by Genentech, Inc., in San Francisco, and in Canada by Hoffman-Laroche (also known as Roche Canada) of Mississauga, Ontario.

Herceptin is designed to combat the HER2 gene (HER2 stands for human epidermal growth factor receptor 2) which is present in about 25% of diagnosed breast cancers This gene helps control how cells grow, divide, and repair themselves by directing the production of special proteins, called HER2 receptors. If the body produces too many copies of the HER2 gene or too many receptors, it results in a more aggressive form of the disease. Patients with HER2 protein over-expression or gene amplification may also experience earlier recurrence, and the disease may not be as responsive to standard therapies.

Testing for the HER2 gene is done on tumour tissue and should ideally be performed at the time of diagnosis. Patients who want their HER2 status checked should ask their physician to have testing done at the time of biopsy or surgery, or on their stored tumour tissue. The tissue will be sent to a pathology lab for further evaluation.

Herceptin has been approved for the treatment of metastatic breast cancer and is now included in the formularies of B.C., Saskatchewan, and Ontario. In Nova Scotia and Quebec, Herceptin may be funded on a case-by-case basis. Alberta is awaiting word from the Common Drug Review (see http://www.hc-sc.gc.ca/english/media/releases/2002/2002_58bk2.htm). In the States, the National Cancer Institute is sponsoring clinical trials of Herceptin for women with non-metastatic breast cancer — i.e., breast cancer that has spread to the lymph nodes but not to other parts of the body.

Side effects that most commonly occur during the first treatment with Herceptin include fever and/or chills and, less frequently, pain, weakness, nausea, vomiting, diarrhea, headaches, difficulty breathing, or rashes. These side effects generally become less severe after the first treatment.

However, long-term treatment with Herceptin can cause damage to the heart muscle and can lead to heart failure. Herceptin can also affect the lungs, causing severe or life-threatening breathing problems and/or allergic reactions. For this reason, women who might benefit from Herceptin should be evaluated very carefully before the medication is prescribed.

Information about the International HERA Trial that led to news about Herceptin is available at http://www.heratrial.com/patient_info/english/summary.htm. Unfortunately, the HERA trial was halted after only one year with the announcement that administration of Herceptin, in tandem with a standard chemotherapy drug, led to a reduction in risk of recurrence of 52%, as compared with women who received chemo alone.

André Picard, writing in The Globe & Mail, concedes that this is an impressive relative risk reduction. However, he goes on to say, "But what matters in the real world is absolute (not relative) risk reduction. Practically speaking, 15% of women taking Herceptin and chemo had a recurrence of breast cancer within four years of diagnosis, compared to 33% of women who took chemo alone. That is an absolute risk reduction of 18%."

" ... Herceptin, according to the studies, cut the death rate by one-third. That sounds impressive, but relative risk reductions always do. In reality, the difference in the death rate between Herceptin and non-Herceptin groups was 2% after three years and 4% after four years.

"Based on these numbers, can we honestly say that Herceptin is an essential life-saving drug?" ("Second Opinion: Be skeptical about the Herceptin hype", The Globe & Mail, Aug. 4, 2005)

The premature halt to clinical trials is becoming more and more common. The pharmaceutical company or companies garner more publicity in order to influence regulatory bodies and get the product to market as quickly as possible.. This often puts undue pressure on the regulatory bodies which, in turn, influence products available on provincial formularies.

Sharon Batt, a founder of BCAM and a bioethics doctoral fellow at Dalhousie University, has remarked on the absence of critical comment about Herceptin, noting that the drug is not a "major advance" and that studies looking at the long-term effectiveness of the drug have not been reviewed. She suggests that breast cancer organizations' responses have been muted because of their ties to pharmaceutical companies, and that the enormous costs of Herceptin (estimated to be about $50,000 per patient per year) will cause Canadians' health care in other areas to be compromised. (See "Drug Company Dollars Come With Side Effects" by Pieta Woolley; Georgia Straight, Vancouver, B.C., July 21, 2005).

BCAM strongly encourages a public discussion on the allocation of funds for medication and technology which have limited capacity to significantly affect quality and length of life.

We at BCAM are always pleased when a new drug appears to be of benefit to women with breast cancer. With regard to Herceptin there remain some important unanswered questions:

• Why has the data not been published? Full disclosure is needed to determine how the tests were performed, which women would benefit, etc.
• If the results were so positive after one year, why not continue and confirm the trend? Continuing the trial would also allow for monitoring of side effects that often assume significance over a longer period of time
• Is it true (as noted in the BCA San Francisco newsletter) that greater access to Herceptin may lead to a shortage of the drug?
• What is the rationale for the cost of this medication? Why is it so costly? Roche Canada has been very quiet during all the recent publicity.

These are questions we ask as an organization — questions the public should be also be asking if we are to determine a rational public policy, i.e., whether it should be available to all and the consequent impact on our public system. These questions assume more importance as additional costly drugs for cancers come onto the market.

These questions are above and beyond any individual woman's decision to take Herceptin.