Our executive leadership team

Andrea Seale is the Chief Executive Officer of the Canadian Cancer Society (CCS). With more than 20 years of non-profit leadership experience, Andrea is dedicated to empowering people to build the causes that make our world more compassionate, healthy and just.

Prior to joining CCS, Andrea was head of the David Suzuki Foundation and held leadership roles with Ecojustice and The Banff Centre for the Arts. She founded Blueprint Fundraising and Communications, specializing in building the capacity of non-profit organizations in Canada and the U.S. She sits on the board of the Canadian Partnership Against Cancer and was named Outstanding Professional Fundraiser for 2022 by AFP Vancouver. Andrea holds a Diploma in Public Relations from Mount Royal University and a Bachelor of Arts in English from McGill University.

Sandra is the Executive Vice President, Mission, Information and Support Services at the Canadian Cancer Society (CCS). In this role, she leads a nationwide team of staff and volunteers focused on delivering a support system to help Canadians prevent cancer and better manage life with cancer, find community and connection and build wellness and resilience.

Sandra joined CCS in 2005 and has held several positions with the organization, including her previous role of Vice President, Cancer Control.

Prior to CCS, her training and work experience was in the cancer research field. She holds a PhD in Molecular Endocrinology from the University of Victoria and has completed post-doctoral training at the Prostate Centre in Vancouver.

Lesa O’Brien is Chief Information and Technology Officer. She leads teams responsible for enterprise-wide digital, data and technology strategies and solutions across the organization to drive CCS's digital transformation. Lesa's portfolio includes Digital Marketing and Solutions, Digital and Technology Operations, Data, Analytics and Solutions and Information Technology.

Lesa joined CCS as Director, Digital Marketing and Engagement in 2017 following the merger with the Canadian Breast Cancer Foundation (CBCF). She was promoted to Vice President, Digital Marketing and Solutions in 2018 and then to Executive Vice President, Digital Strategy and Technology in 2023.

Prior to CCS, Lesa spent 18 years leading digital teams to drive digital transformation in the healthcare, and not-for-profit sectors. She holds a Master of Science in Nutritional Sciences from the University of Guelph.

Dr Sarah Viehbeck is the Chief Mission Officer at the Canadian Cancer Society (CCS). In this role, she leads CCS's mission teams in advancing the organization's strategic priorities and driving meaningful impact for people living with cancer today and for future generations. Her portfolio includes Research, Advocacy, Policy, and Information and Support Services. Dr Viehbeck joined CCS in 2026.

Prior to joining CCS, she served as Chief Science Officer and Vice President, Science and Policy Integration at the Public Health Agency of Canada (PHAC) and held leadership positions at the Canadian Institutes of Health Research, including as Associate Vice-President of Research Strategy. She spearheaded the development of the PHAC Science Strategy and played a key role in national research coordination for COVID-19 and other infectious disease outbreaks.

Dr Viehbeck holds a PhD and Master of Science in Health Studies and was named the 2023 Distinguished Alumni from Brock University where she completed her undergraduate studies. She is recognized for her collaborative leadership and commitment to health equity, with extensive experience as a boundary spanner linking science, research and public policy sectors in Canada and globally. A bilingual leader, she has worked across disciplines, sectors and jurisdictions to advance public health policy and lead complex changes.