There were trends for obese patients to have shorter recurrence-free survival and overall survival than normal-weight patients, although these findings did not reach statistical significance.
“This is an important step toward identifying new and relevant prognostic factors for this disease and could lead to more-effective treatment strategies,” said lead author Neil Iyengar, MD, a medical oncology and hematology fellow at MSKCC.
Obesity has been shown to shorten survival in several common cancers, including those of the breast, colon, and esophagus, but previously was not known to affect the prognosis of SCC of the tongue. According to Dr. Iyengar, this is because previous studies were not sufficiently focused to find an effect.
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“Most prior studies investigating interactions between body mass index and head and neck cancers included multiple tumor sites—tongue, floor of mouth, and tonsil—and multiple stages of disease,” he said. “In addition, many patients have weight fluctuations right around diagnosis, either from the cancer or associated habits like tobacco and alcohol use. All these confounding factors have made it difficult to clearly understand the effect of obesity.”
It is not known how obesity might reduce survival in patients with cancer of the tongue, but inflammation could be the key. Three years ago, the same researchers found that obesity is associated with low-grade, chronic inflammation of adipose tissue in the breast, which in turn raised concentrations of aromatase, promoting cancer growth. The tongue also contains fat cells and might be subject to a similar process.
- Iyengar NM, Kochhar A, Morris PG, et al. Impact of obesity on the survival of patients with early-stage squamous cell carcinoma of the oral tongue. Cancer. 2014 Jan 21 [Epub ahead of print] doi: 10.1002/cncr.28532.