Her practice and research are devoted to breast cancer. In 1994, she created a program for hereditary breast and ovarian cancer patients, which introduced genetic counselling and testing to the Odette Cancer Centre. Since 1997 she has led a study to explore the role of MRI in screening women with an inherited predisposition to develop breast cancer. This research helped make annual MRI surveillance the standard of care for this very high-risk population and led to the development of the high-risk Ontario breast screening program. Since 2011 the program has offered annual MRI and mammography to women at very high risk for breast cancer between ages 30 and 70.
In addition, Dr. Warner is the creator and director of PYNK: Breast Cancer Program for Young Women. Launched in 2008, it is the only interdisciplinary clinical and research program in Canada for breast cancer patients diagnosed at age 40 or younger. PYNK addresses the special medical and psychosocial needs of this population and offers these women enrolment in studies focusing on women in this age group. PYNK has a dedicated nurse who follows these women from time of diagnosis, throughout treatment and follow-up to provide counseling, resources and timely referral for issues that include fertility, symptoms of premature menopause and help with childcare. The monthly In-The-PYNK support group is available to young women across the Greater Toronto Area who have been diagnosed with breast cancer.