A new, prospective cohort study has analyzed data on over 20,000 Swedish children to determine if congenital heart disease (CHD) diagnosis increases infants’ risk of developing cancer.
There is a known association between the prevalence of congenital heart disease (CHD) in adults and their increased risk of developing cancer. Now, for the first time, researchers have investigated whether there is a similar increased risk of cancer in children and young adults with CHD, compared with the general population.
CHD prevalence at birth is close to 1% and the survival rate of CHD patients into adulthood is greater than 95%. Increased patient survival is associated with the incidence of secondary morbidities, such as cancer.
In this novel, prospective, cohort study, researchers analyzed data on 21,982 patients from the Swedish Patient Register and Swedish Cause of Death Register. Patients eligible for study inclusion were born between 1970 and 1993 and received any type of CHD diagnosis, at any age.
Participants were categorized into cohorts according to their birth year: those born from 1970–1979, 1980–1989 and 1990–1993. Patients were assessed for a maximum of 41 years, from birth, until cancer diagnosis — as defined by International Statistical Classification of Diseases and Related Health Problems (ICD) codes— death or study termination in 2011.
Each of the 21,982 patients included in the study were matched by birth year, sex and county to ten ‘healthy’ controls (individuals without CHD) from the Swedish Total Population Register.
Of the 21,982 participants with CHD, 428 patients — equivalent to 2% of the CHD cohort — developed cancer.
By contrast, 0.9% of individuals without CHD developed cancer during the study period (2072 of the 219,816 total participants without CHD).
The mean hazard risk of cancer development amongst children and young adults with CHD, compared with matched controls without CHD, was calculated to be 2.24.
Hazard risk for cancer development was correlated with participants birth year; the hazard risk for children and young adults born between 1990 and 1993 was 3.37.
Cancer development risk in patients with CHD was not significantly different between men and women.
In the study, the authors commented: “We found an increased risk of cancer compared with healthy matched controls that was already present in childhood. The absolute risk of developing cancer among patients with CHD increased for each 10-year birth cohort…We found a more than 2-fold higher risk among patients with CHD of developing cancer compared with controls.”
Further, the researchers noted, in the study, that “…the relative risk of cancer was high, regardless of whether [CHD] patients had undergone surgical procedures.”
In the study, the authors concluded: “Patients with complex heart lesions, such as conotruncal defects, had a particularly high risk of cancer. This finding suggests that particular attention should be paid to early warning signs of cancer and promotion of a healthy lifestyle. Further research on the mechanisms of cancer in this young patient group is warranted.”
Mandalenakis Z, Karazisi C, Skoglund K et al. Risk of Cancer Among Children and Young Adults With Congenital Heart Disease Compared With Healthy Controls. JAMA Netw. Open, 2(7), e196762 (2019).