The study, which is published in the Journal of Clinical Oncology, involved 121 women with progressive or recurrent metastatic breast cancer. Metastases were biopsied and examined for the expression of three biomarker receptors (for estrogen, progesterone and Her2) and the results were compared with biopsies from the original breast tumours. Approximately 38% of women had a change in at least one biomarker in their metastases compared to their original tumours, and this led to a change in treatment strategy in 14% of the women (one in seven).
"This study represents a major advance in the development of more personalized therapies for breast cancer," said Dr Clemons, a breast cancer specialist at The Ottawa Hospital, clinical investigator at the Ottawa Hospital Research Institute and associate professor of medicine at the University of Ottawa. "By examining the molecular characteristics of tumours and metastases, we are now increasingly able to provide tailored therapies that are more likely to work and less likely to have side effects for individual women. Further research is needed though, because there are still far too many women who ultimately die of breast cancer, and cancer overall is now the number one killer in Canada."
This research was conducted in partnership with investigators at the University Health Network's Princess Margaret Hospital. It was funded by the Canadian Breast Cancer Foundation. Dr Clemons and other cancer researchers at the Ottawa Hospital Research Institute are also supported by The Ottawa Hospital Foundation.