Childhood experience of parental cancer is linked to poorer school grades, educational attainment, and subsequent earning power as a young adult, suggests a data linkage study of more than 1 million Danes, published online in the Journal of Epidemiology & Community Health.
The more severe the parent's cancer, the greater the impact seemed to be, the findings indicate.
One in three people will be diagnosed with cancer at some point in their lives, and it has been estimated that one in every six survivors of the disease lives with children.
To find out about the potential impact on overall educational attainment and income by the age of 30 of having a parent with cancer during childhood, the researchers drew on 1,155,214 Danish children born between January 1978 and December 1999.
School performance was measured by final grade point average, based on a combination of exam results and teacher assessment achieved by ninth grade (around the age of 15) in 795,160 children born between 1986 and 1999.
Information on overall levels of educational attainment and disposable income by the age of 30 was compiled using national statistical data for 360,054 children born between 1978 and 1984.
Details of parental cancer were obtained from the Danish National Patient Registry. This was defined as a diagnosis before the child was 18, and for the purposes of school performance, before the age of 15.
Disease severity was defined by average 5-year survival in Denmark for a particular type of cancer, and categorised as good (above 85%); intermediate ( 50-85%); and poor (below 50%).
In all, around one in 20 children (4-5%) had had at least one parent diagnosed with cancer. Five year survival was categorised as good in around half of these cases. Among the mums, breast, gynaecological and skin cancers were the most common types; among the dads, these were cancers of the prostate, bladder, bowel, lung, and skin.
Children with experience of parental cancer had a lower final grade average than children whose parents had not had cancer, when potentially influential factors, such as parents' educational attainment, were taken into account. Although this difference was small, it was nevertheless statistically significant.
The grade average was even lower among children whose parents had a poor chance of surviving five years or who had died of their disease. But it was slightly higher among those whose parents had a good chance of surviving five years or who were still alive by the child's 15th birthday.
Parental cancer was also associated with a greater risk of low educational attainment, particularly if it was the father who had been affected.
What's more, this risk was 1.5 times higher if the chances of surviving 5 years were poor, and 1.6 times higher if the parent died. No such associations were evident if the outlook was good or if the parent was alive by the child's 18th birthday.
There was a moderately increased risk of lower earnings power by the age of 30 if a parent had had cancer. This risk was highest among children whose parents had a poor chance of surviving 5 years or who died of their cancer.
Particularly badly affected were children who had been under 5 when the diagnosis was made, suggesting that any impact of parental cancer in early childhood may extend across the life course, say the researchers.
This is an observational study, and as such, can't establish cause. But the researchers nevertheless explain: "In a life course perspective, parental cancer in childhood could be considered as a potential early life stressor that may increase the health vulnerability to later life exposures, expanding the risk of later social disadvantage and poor adult health."
They conclude that their findings: "may indicate that some children who experience parental cancer would benefit from appropriate support and early educational rehabilitation in [their] teenage years."