Can prescription drugs help to prevent breast cancer?
Breast cancer is the most commonly diagnosed cancer in women and has a significant impact in terms of quality of life, particularly in the acute phases of treatment, which can involve aggressive chemotherapy and full or partial mastectomy. Given the huge impact of breast cancer on women, on their families and on healthcare provision, identifying an effective prevention strategy would be of immense societal benefit.
Data access has been approved for a research project to study whether use of bisphosphonates and omeprazole, (widely prescribed medications for osteoporosis and gastric disorders) reduce the risk of breast cancer.
There are several factors which influence a woman’s risk of developing breast cancer, says Brendan Bakos, a University of British Columbia Masters student, who is conducting the research as part of his Masters studies. “Risk factors include modifiable ones, such as use of hormone replacement therapy, and maintaining a healthy weight, in addition to non-modifiable ones, such as genetic predisposition. A number of subtypes of breast cancer have been identified and research is beginning to demonstrate that the effects of known risk factors vary between these subtypes of breast cancer.”
Although prevention strategies for breast cancer exist, these are chiefly lifestyle modifications with limited effectiveness. Other strategies are available, but are often invasive, such as a full or partial mastectomy, and are reserved for extremely high-risk cases. To date, no safe and effective pharmaceutical ‘chemopreventive’ agents have been identified that may be widely used for targeted prevention among high risk women. Yet, increasing evidence suggests that several prescription medications prescribed for conditions other than cancer, may shape a woman’s risk of getting breast cancer.
In addition to bisphosphonates and omeprazole, several other pharmaceuticals are also of interest. These include anti-depressants; statins (used to treat high cholesterol); and angiotensin-converting-enzyme inhibitors and beta blockers (used to treat hypertension). Although the latter have been studied more extensively, results have been conflicting and little work describes their association to subtype-specific risk.
The study builds on previous research led by Mr Bakos’s supervisor, Dr John Spinelli of the BC Cancer Agency. This population-based, case-control study, funded by the Canadian Institutes of Health Research, investigated the molecular epidemiology of breast cancer. In this study, over two thousand women completed a detailed survey providing information on family history of cancer, education and ethnicity. Participants also provided biological samples for genetic information, and consent for researchers to access their medical records. Mr Bakos’s research will collect comprehensive information on participants’ prescription drug use, including bisphosphonates and omeprazole.
PopData will link BC Cancer Agency data with PharmaNet data for the project.