Study: Leptin Level May Be Indicator of Breast Cancer Risk

Measuring a woman's level of leptin, a hormone linked with the regulation of body fat, may offer an additional indicator of her risk of developing breast cancer, according to researchers at the M. D. Anderson Cancer Center.

Their study, published in Proceedings for the 2003 Annual Meeting of the American Association for Cancer Research, suggests that leptin levels potentially reveal a woman's lifetime history of eating dietary fat, which is linked to increased bioavailable estrogen and higher breast cancer risk.

"The amount of leptin found in a woman's blood stream can indicate her accumulation of fat over the years," said Richard Hajek, an instructor at M. D. Anderson's Center for Research on Minority Health. "Measuring leptin could be an additional marker for assessing breast cancer risk."

Leptin is a hormone produced by fat tissue that signals to the brain when it is time to stop eating. Researchers said that as body fat increases, more leptin is produced, which acts to reduce food intake, and the converse is true.

In the research, researchers studied a group of 38 postmenopausal Hispanic women to see how leptin levels fluctuated between women who switched to a high-fiber, low-fat diet and women who switched to high-fiber with no modification in their fat intake.

They found that despite different beginning low or high beginning leptin levels, the volunteers who ate more fiber and less fat reduced their levels of leptin and some shed a few pounds. Therefore, the researchers said, leptin levels potentially revealed their lifetime history of eating fat.

"Measuring current body weight and fat intake doesn't offer that kind of perspective," Hajek said.

Thus, when determining the breast cancer risk that a woman has accumulated from eating fat over her lifetime, leptin, body fat composition, and bioavailable estrogen together may offer a more precise indicator, Hajek added.

Other sources: M.D. Anderson Cancer Center