Findings from a recent study published in the Journal of Thoracic Oncology challenge the idea that an obesity paradox contributes to reduced lung cancer risk—instead, the data suggested that obesity may be associated with enhanced lung carcinogenesis.
“Overall, our data clearly associate central adiposity with heightened lung cancer risk,” stated lead study author Joseph Barbi, PhD, Assistant Member in the Department of Immunology at Roswell Park Comprehensive Cancer Center.
Background and Study Methods
Researchers have suggested that there is a correlation between high body mass index and decreased lung cancer risk, in what has been called an "obesity paradox." A research team sought to learn more about the relationship between the two through clinical and preclinical modeling.
They conducted a case-control study of 1,170 individuals at high risk for early stage lung cancer, who were stratified by total abdominal fat area, as determined by computed tomography scans. The team also looked at airway gene expression as a function of total abdominal fat area in 278 additional patients, as well as the impact of obesity on chemical- and mutation-driven lung carcinogenesis in models. Additionally, they profiled the effects of the immune environment of murine lungs as well as patients' bronchoalveolar lavage using flow cytometry.
Key Findings
Researchers found a relationship between lung cancer and higher total abdominal fat area in both univariate and multivariable models.
Suppressed immune activity signals were found in the gene expression of patients with high total abdominal fat area airways.
In preclinical findings, the lungs of obese mice showed more abundant potentially suppressive myeloid cells, activated regulatory T cells, and effector T-cell deficits at both baseline and during carcinogenesis, compared with more lean control mice.
The study authors suggested that obesity-enhanced regulatory T cells can cause rapid tumor growth. Flow cytometry analysis of patient airway leukocytes also suggested that lung immune surveillance may be compromised in patients with high total abdominal fat area.
Sai Yendamuri, MD, MBA, FACS, Senior Vice President, Strategy, Business Development and Outreach and Chief Strategy Officerof Roswell Park Comprehensive Cancer Center, is the corresponding author of the Journal of Thoracic Oncology study.
DISCLOSURES: For full disclosures of the study authors, visit jto.org.
