Prof DeFazio holds the Sydney-West Chair in Translational Cancer Research, University of Sydney. She is Director, Center for Cancer Research at the Westmead Institute for Medical Research, Westmead Hospital; Director of Sydney Cancer Partners; and Convenor of the University of Sydney Cancer Research Network.

Prof DeFazio chairs the TR-ANZGOG Steering Committee and is a member of the ANZGOG Research Advisory Committee and the ANZGOG Ovarian Tumour Type Working Group. Her research is focused on understanding treatment response and resistance in ovarian cancer and she leads INOVATe, a precision medicine program, matching ovarian cancer patients to clinical trials through molecular profiling.