Child-abuse victims more likely to develop cancer
TheGlobeandMail.com – Life/Health – Child-abuse victims more likely to develop cancer:
A Canadian study finds that people who’ve been physically abused as children were 49 per cent more likely to develop cancer as adults
Jun. 26, 2009. Jennifer Yang
Childhood physical abuse may be linked to the development of cancer later in life, a new University of Toronto study has found.
The study discovered that people who’ve been physically abused as children were 49 per cent more likely to develop cancer as adults. It used survey results from 13,092 people living in Saskatchewan and Manitoba and will appear next month in the journal Cancer.
While substantial research already links childhood abuse with mental-health problems and illnesses such as irritable bowel syndrome, there is little scholarship on the connections between childhood physical abuse and cancer, says the study’s lead author, Esme Fuller-Thomson, a professor with the U of T’s Factor-Inwentash Faculty of Social Work and Department of Family and Community Medicine.
She knows of only one previous study associating childhood physical abuse and cancer but it was conducted 11 years ago.
The study failed to control for adult circumstances that could cause cancer, such as drinking, smoking, inactivity and poor socioeconomic status. It also neglected to consider childhood stressors, such as parental divorce or early poverty.
For her study, Dr. Fuller-Thomson adjusted for all of these factors and still found a strong association between childhood abuse and cancer.
“We were very surprised,” she says. “To see the association didn’t disappear when we adjusted for those factors indicated there was something else going on.”
What that something else might be, however, remains unclear. One possible explanation is the theory that abused children are more prone to abnormal levels of cortisol, a fight-or-flight hormone that helps people deal with stressful situations. Chronic stress has been linked with other maladies such as heart disease and arthritis so perhaps cortisol levels also affect cancer rates, Dr. Fuller-Thomson suggests.
The association between emotional trauma and physical health has also been documented in previous studies that found bereaved people have suppressed activity of natural killer cells, which troll the body surveying for tumour cells. In a 2000 Israeli study, for example, people who’ve lost adult children exhibited a higher propensity for developing non-Hodgkins lymphoma and leukemia.
Dr. Fuller-Thomson emphasizes that her study’s conclusions are very preliminary however, and urges people with histories of physical abuse to refrain from assuming they’ll develop cancer. She concedes there are also several holes to plug in her study – her data was taken from the 2005 Canadian Community Health Survey and respondents do tend to under-report physical abuse. Something else to consider is the possibility that experiencing cancer might cause someone to look back and evaluate their childhood differently, Dr. Fuller-Thomson says.
There is ample room for further research and Dr. Thomson-Fuller hopes her study will trigger other researchers to explore links between early childhood experiences and cancer.
“Social scientists typically do not look at what’s potentially going on under the skin and medical scientists are only beginning to think about important issues such as poverty and education,” she says. “The interactions between who you are, your position in society and what’s going on physiologically; I think we need to look at those more closely.”