Abdominal Fat and Mortality in Patients With Colorectal Cancer
For patients with colorectal cancer, new research shows a clearer connection than previously known between fat deposits in certain areas of the body and higher rates of death from all causes within 7 years of cancer diagnosis. These findings were published by Brown et al in the Journal of the National Cancer Institute.
“[Patients with] colorectal cancer and their oncologists need to know how obesity and body composition predict clinical outcomes after diagnosis,” said lead study author Justin C. Brown, PhD, Director of the Cancer Metabolism Program at Louisiana State University’s Pennington Biomedical Research Center. “However, patients have found there are few clear answers to even the simplest of questions, such as, ‘Will my weight influence my outcome?’ or ‘Should I lose some weight?’”
Methods
Dr. Brown and colleagues examined the health outcomes of more than 3,200 patients with stage I to III colorectal cancer in Kaiser Permanente’s Northern California Region who were diagnosed between 2006 and 2011. The researchers examined the patients’ health outcomes through the end of 2016.
Visceral and subcutaneous fat were quantified using computed tomography. The primary endpoint was all-cause mortality.
Findings
Visceral fat was prognostic of mortality in a reverse L-shaped pattern (nonlinear P = .02); risk was flat to a threshold (≈ 260 cm2), then increased linearly. Subcutaneous fat was prognostic of mortality in a J-shaped pattern (nonlinear P < .001); risk was higher at extreme (< 50 cm2) but lower at intermediate values (> 50 to ≤ 560 cm2).
Researchers found that male patients with colorectal cancer with a high amount of subcutaneous fat were more than twice as likely to die within 7 years of diagnosis as male patients with very little subcutaneous fat. However, female patients with colorectal cancer with a high amount of visceral fat were more than twice as likely to die within 7 years of diagnosis as female patients with very little visceral fat.
The researchers concluded, “Visceral and subcutaneous adipose tissue were prognostic of mortality in patients with colorectal cancer; the shape of these associations were often nonlinear and varied by patient sex. These results offer insight into the potential biological mechanisms that link obesity with clinical outcomes in patients with cancer, suggesting that the dysregulated deposition of excess adiposity is prognostic of mortality.”
Disclosure: The study was supported by the National Cancer Institute and the National Institute of General Medical Sciences. For full disclosures of the study authors, visit academic.oup.com.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
