Being obese increases the risk of breast cancer in post-menopausal women, shortens the time between return of the disease and lowers overall survival rates.
Italian researchers speaking at Experimental Biology 2007 in Washington, DC, now report evidence on how leptin, a hormone found in fat cells, significantly influences breast cancer development and progression in mice. This new understanding, says Dr. Sebastiano Ando, establishes a new mechanism for the link between obesity and breast cancer and suggests new targets for drugs that could intervene in that mechanism.
Leptin, an adipocyte-derived hormone, is best known for its efforts to send messages to the body that no more food is needed, a process that may go awry in many people with obesity. But it also is involved in many other processes, from reproduction and lactation to cell differentiation and proliferation. Leptin is activated by signals from the leptin receptor ObR, and it is this partnership that has previously been found to be involved in the development of breast cancer. It was recently reported, for example, that leptin was detected in 86.4 percent of primary breast tumors and that its expression was highly correlated with ObR.