Obesity During Childhood Cancer Treatment Increases Risk of Secondary Cancer

Obesity during childhood cancer treatment may increase the risk of developing second malignant neoplasms, according to research published in Cancer Epidemiology, Biomarkers & Prevention.

In the case-control study, patients with second malignant neoplasms (case; n=59) and those with a single-primary cancer (control; n=130) were selected from the California Cancer Registry. These patients had a primary cancer diagnosis at <21 years and were treated at the Children’s Hospital Los Angeles between 1988 and 2014. Controls were matched 3:1 to cases at the registry level by clinical factors.

Median age at primary cancer diagnosis was 6 years, 64.5% were male, and median time from primary cancer to second malignant neoplasm was 7.5 years. Almost a third of patients (31.7%) were obese or overweight.

Obesity during treatment a risk factor for secondary cancer

There was a significantly increased risk for second malignant neoplasm among patients who were obese at both diagnosis and end of therapy (adjusted odds ratio [OR] = 4.44; 95% CI, 1.37–14.34).

Researchers observed elevated but non-significant associations between second malignant neoplasm and higher body mass index (BMI) Z-score at diagnosis (OR=1.27; 95% CI, 0.99-1.63) and higher BMI categories at diagnosis (adjusted OR overweight = 1.25; 95% CI, 0.55-2.52; adjusted OR obese = 2.51; 95% CI, 1.00-6.29).