University of Toronto researchers have found a significant link between child abuse, emotional trauma, and the onset of cancer in adulthood. Cancer risk increased by 49 per cent in participants who had been physically abused as children when compared with people who had not faced abuse. The risk decreased only slightly, to 47 per cent, when the model was adjusted for age, sex, and race.

Dr. Esme Fuller Thomson, researcher and professor at the Factor-Inwentash Faculty of Social Work, and PhD student Sarah Brennensthul looked at regional data from Manitoba and Saskatchewan from the 2005 Canadian Community Health Survey. Of the 13,092 respondents, 7.4 per cent reported that they had been physically abused as a child by someone close to them, and 5.7 per cent reported being diagnosed with cancer by a health professional.

The criteria for childhood physical abuse were based on survey questions addressing adult socioeconomic status and experiences during childhood. Individuals who responded “yes” to the question “Were you ever physically abused by someone close to you?” were categorized as abused.

Further research is needed to explain the connection between abuse and cancer, although the findings are consistent with similar research linking stress with ill health.

Thomson explained, “With every stressor, you respond with a huge amount of this hormone [cortisol] which sends your heart rate up and can cause suppression of your immune system.”

Brennenstuhl, co-author of the article, echoed a similar sentiment in an interview with News at U of T : “One important avenue for future research is to investigate dysfunctions in cortisol production—the hormone that prepares us for fight or flight as a possible mediator in the abuse-cancer relationship.”

In a more recent study published in the November issue of Arthritis Care & Research, Thomson and Brennensthul looked at the relationship between childhood physical abuse and osteoarthritis. They found that adults had a 56 per cent increased risk of osteoarthritis if they had been abused as children.

“I was totally surprised that the relationship was so strong, so there is something going on, but right now it is a black box. It is a question mark right now,” commented Thompson. “The finding of an abuse-cancer link is fascinating. As with all science, however, these findings need to be replicated in other samples and in longitudinal research before we have a clearer idea of what is really going on.”