Mechanisms that link inflammation, obesity and cancer

The latest issue of the Journal of the National Cancer Institute comments on recent research investigating how the inflammatory cytokines (cell signaling molecules), which are increased under various conditions that include obesity, can turn healthy liver cells into malignant ones:

"As obesity's ties to multiple cancers strengthen, a new study suggests that inflammation may be the primary culprit in at least one malignancy: liver cancer."

The study itself was recently published in the journal Cell. The report that...

"We now demonstrate that either dietary or genetic obesity is a potent bona fide liver tumor promoter in mice...Obesity-promoted HCC (hepatocellular carcinoma = liver cancer) development was dependent on enhanced production of the tumor-promoting cytokines IL-6 and TNF, which cause hepatic inflammation and activation of the oncogenic transcription factor STAT3."

Readers here will not be surprised that they also assert...

"The chronic inflammatory response caused by obesity and enhanced production of IL-6 and TNF may also increase the risk of other cancers."

Three important points: (1) nothing increases the storage of fat in the liver like the high levels of insulin associated with insulin resistance (remember the link between insulin and fatty liver disease). (2) Chronic inflammation, whatever the cause, is a component of most chronic degenerative diseases. (3) Those of us who are health care professionals should be using the available laboratory tests for inflammatory cytokines in the care of our patients when appropriate; readers who are patients should be asking about them.