Childhood trauma may leave a biological and psychological imprint that lasts decades. A new study from researchers at the University of Toronto and the University Health Network suggests that childhood sexual abuse may be linked to a significantly higher likelihood of cancer later in life.
Researchers explored whether different types of childhood adversity, including childhood sexual abuse, childhood physical abuse, and exposure to parental domestic violence, were associated with cancer diagnoses in older adulthood.
The prevalence of cancer was more common among those who had experienced childhood sexual abuse (36%), childhood physical abuse (28%), and parental domestic violence (27%), compared to the general population (21%).
"These findings highlight how experiences early in life are associated with negative health outcomes many decades later" said first author Matthew R. Langiano, a recent MSW graduate of University of Toronto's Factor-Inwentash Faculty of Social Work (FIFSW.) "A life-course lens may deepen our understanding of cancer risk.
When these three childhood adversities were considered at the same time, the strongest association with cancer was evident among those who were child sexual abuse survivors. Older Canadians who experienced sexual abuse during childhood had about twice the odds of reporting a cancer diagnosis later in life, even after accounting for the other types of childhood adversities and many factors such as smoking, income, and other chronic health conditions.
"These findings reinforce why trauma‑informed care matters, especially in oncology," said co‑author Carmine Malfitano, MSW, RSW, PhD, Director of Research and Education at the Centre for Psychology and Emotional Health and Clinical Social Work Specialist at Princess Margaret Cancer Centre. "When providers understand that a patient's history may shape how they engage with screening or treatment, care can become more supportive and responsive."
The researchers emphasize that the study identifies associations rather than cause-and-effect relationships. However, even after accounting for many well-known cancer risk factors, the link between childhood sexual abuse and cancer remained strong. This suggests the association is unlikely to be explained simply by higher rates of smoking, substance use disorders, or poverty among those who experienced abuse.
Senior author, Professor Esme Fuller-Thomson, Director of the Institute for Life Course and Aging at FIFSW, University of Toronto, suggest that chronic stress may be one possible explanation. "Previous research has shown that early trauma can leave long-lasting biological consequences, affecting stress hormones, inflammation, and immune system functioning—processes that may influence cancer development. Childhood trauma may echo across a lifetime of health."
The researchers stress that more work is needed to understand these potential pathways. Future longitudinal studies will be important for clarifying how early life experiences may shape health decades later.
The study, published in PLOS One, examined nationally representative data from 2,636 Canadians aged 65 and older from the 2022 Canadian Mental Health and Access to Care Survey.
