Obesity and Physical Activity as Factors Influencing Cancer Risk in Childhood Cancer Survivors

Recent research published in JAMA Oncology highlights the significant impact of body mass index (BMI) and physical activity levels on the likelihood of developing new neoplasms among survivors of childhood cancer. The study, led by Dr. Lenat Joffe from Northwell Health in New Hyde Park, New York, analyzed data from a large cohort of childhood cancer survivors diagnosed before age 21 between 1970 and 1999, followed through September 2019.

The research involved 22,716 participants with available BMI data, out of which 2,554 neoplasms were identified in 2,156 individuals with a median age of 37.4 at diagnosis of the secondary tumors. The findings revealed that survivors with higher BMI, particularly those classified as obese, faced increased risks for developing solid organ tumors, central nervous system (CNS) tumors, and skin cancers, with relative rates of 1.22, 1.47, and 1.30 respectively.

Conversely, engaging in higher levels of physical activity was associated with a decreased risk of neoplasm development. Survivors who participated in moderate physical activity (15 to 21 metabolic equivalent hours per week) exhibited a substantially lower risk—relative rates of 0.61 for solid organ tumors, 0.65 for CNS tumors, and 0.50 for skin cancers—compared to those with minimal activity levels.

The study also found notable associations between BMI and physical activity with specific tumor types, such as meningiomas and thyroid carcinomas. However, no significant links were observed with breast, colorectal, or hematologic cancers. These findings underscore that long-term lifestyle factors like weight management and physical activity levels can influence cancer risks well after the completion of initial cancer therapy.

The authors emphasized the importance of incorporating lifestyle interventions into survivorship care plans to potentially mitigate the risk of secondary neoplasms. Two of the study's authors disclosed affiliations with the biopharmaceutical and medical device industries.

This research reinforces the role of healthy lifestyle habits in reducing long-term cancer risks among childhood cancer survivors and suggests further avenues for intervention to improve survivorship outcomes.

source: https://medicalxpress.com/news/2025-06-obesity-linked-subsequent-neoplasms-childhood.html