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).