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Timothy Whelan

Timothy Whelan

Health Services Research in Cancer
Canada Research Chair

Faculty of Health Sciences

Department of Oncology


Research Involves

Using clinical trials to evaluate new radiation technologies for the treatment of patients with breast cancer and the use of biological markers to predict response to radiation therapy.

Chair Overview

Affecting over 26,000 women in 2017, breast cancer is the most common cancer in women. The disease is often limited to the breast and surrounding lymph nodes and is treated primarily by surgery. However, about 70% of women will also receive radiation therapy (RT) in addition to other treatments (chemotherapy and/or endocrine therapy) to prevent recurrent disease.

The last two decades have seen major advances in the delivery of RT because of improvements in computing and imaging technology. It can now be delivered more precisely, permitting dose intensification to the cancer, and a reduction of dose to the surrounding normal tissues, thus avoiding toxicity. There have also been major research discoveries around the molecular biology of breast cancers. Gene array studies have given rise to a new taxonomy to classify breast cancer into subgroups that more accurately predict risk of recurrence and response to treatment compared to classic clinical factors such as tumour size or lymph node involvement.

Dr. Timothy Whelan, Canada Research Chair in Breast Cancer Research, will use the technologic advances and improved understanding of breast cancer biology to tailor RT to the individual patient in three ways. First, Dr. Whelan is evaluating whether molecular biomarkers of cell proliferation can identify low risk cancers and help avoid the use of RT in these cases. Second, Dr. Whelan and his team are studying the effectiveness of short treatments over one week, given to just part of the affected breast, compared to the usual whole breast radiation over three weeks. Finally, this work will determine whether biomarkers can be used to tailor the use of more extensive radiation for high risk patients only and avoid it in patients at low risk.