Breast Cancer Report
What's Keeping New Chemotherapy Regimen Out of Reach for Canadian Women with Breast Cancer?
(September 2000, Cancer Care in Canada)
The diagnosis is early-stage, node positive adjuvant breast cancer. You undergo surgery and possibly radiation, then discuss with your doctor what form of chemotherapy can stop your cancer from returning. There is no sure-fire cure here, only the opportunity to improve your odds of staying cancer-free. In many ways, your future may well depend on the type of chemotherapy you receive.
In cancer research today, chemotherapy is where the action is. New compounds are being developed regularly and added to existing regimens to improve your chances of keeping a cancer at bay. Worldwide, clinical trials are testing a variety of combinations of older and newer agents. For example, most clinical trials in node positive adjuvant breast cancer now incorporate a class of drugs called taxanes as an important part of treatment.
At the 1998 meeting of the American Society of Clinical Oncology, preliminary results of one such clinical trial were presented. The study, which involved more than 3,000 women, was the largest adjuvant breast cancer study ever conducted. Its results showed that two older chemotherapy compounds, adriamycin and cyclophosphamide, given along with a newer taxane called paclitaxel in a combination known all together as AC+T, significantly improved survival and reduced cancer recurrence. The study results demonstrated a significant advantage for people who used the three drugs, with a 22% reduction in the risk of relapse and a 26% reduction in the risk of death.
'In the United States, AC+T was felt to represent the single most significant advance in the treatment of breast cancer in the past 20 years,' says Dr. Brian Leyland-Jones, Professor of Medicine and Oncology at Montreal's McGill University. But while the new chemo drugs have been adopted as the updated standard of care in the US, they have had little or no impact on treatment options available to Canadian women. Paclitaxel is not yet approved for use in early stage breast cancer by Health Canada, and only women in a very few provinces can gain access to the combination through clinical trials. Still, Canadian oncologists are already using this class of chemotherapy for ovarian cancer and are eager to include it for breast cancer patients. The question is, why does it remain unavailable?
Chemotherapeutic research for breast cancer in Canada currently concentrates on comparing an older chemotherapy for node-positive (Stage II) breast cancer, called cyclophosphamide, methotraxate and fluorouracil (CMF) to a newer combination, cyclophosphamide, epirubicin and fluorouracil (CEF). Based on Canadian research published in 1998, CEF was adopted as an additional standard adjuvant therapy in 1998 Canadian guidelines.
While many Canadian cancer specialists have justified the unavailability of AC+T in Canada by pointing to the 'preliminary' or 'inconclusive' results of the U.S study, Dr. Bill Hryniuk, Director of Detroit's Kemanos Breast Cancer Centre, thinks the opposite. He believes that the two years since the study's release have helped prove its contentions. 'The results are clear cut for patients who participated,' he says. 'Disease-free survival is 25% improved. Overall survival at 3 years is 15% better, or more, than for those receiving AC without paclitaxel.' And, he says, the response appears to be concentrated in one disease subset: hormone receptor status negative tumour patients. These women may have even more to gain by receiving the combination. Dr. Hudis states the case even more strongly: 'I am not willing to NOT give paclitaxel until there is evidence I should not.'
Following the adoption of AC+T as standard care in the US, a group of Canadian breast cancer survivors led an inquiry in 1999 into why the AC+T combination was not being made available to Canadian women with early stage node positive breast cancer. The 200 responses received from provincial and federal cancer bodies provided few direct answers but raised a number of questions about the mechanisms used to determine adopting new treatments in Canada. More importantly, the criteria physicians follow to decide what treatments a patient should be informed about were uneven and unclear. In the final report on the survey, this last issue was considered the most important. 'Physicians have a responsibility to discuss all treatment options that might reasonably benefit patients, even those treatments that are not available under provincially funded health plans,' wrote Pat Kelly. 'This disclosure allows patients the opportunity to try and obtain treatments elsewhere or lobby to have them made available here.'
On April 17, 2000, Health Canada approved paclitaxel as an adjuvant therapy for early stage breast cancer. However, it remains unclear whether that approval will translate into greater accessibility to AC+T for Canadian women. Provincial therapeutics committees are currently deciding whether or not to include AC+T in their breast cancer treatment guidelines, and a new study of Canadian women will get underway shortly. However the results are several years away. In the meantime, Canadian women continue to be denied access to treatment with AC+T outside of clinical trials.(This article appears in Cancer Care in Canada, September 2000.)