Researchers at the Lineberger Comprehensive Cancer Center at the University of North Carolina (USA) explored the biological mechanisms behind obesity and its relation to cancer. According to their findings in experimental models, those obese and older experienced greater tumor growth than the younger, obese and lean, and also compared to lean and older mice.
"The worst tumors, the really aggressive and metastatic tumors, were in obese and older individuals. The less tumorigenic image was in young, thin individuals," explains Stephen Hursting, one of the authors of this series of studies presented at the 2019 of the American Cancer Research Association (ACCR). in English).
The researchers also found an increase in inflammation in older models as well as in younger and obese people, which led them to believe that there are biological connections that could be driving the links between cancer and obesity and aging.
Another paper provides information on what may be helping to increase obesity-related resistance in certain chemotherapy treatments for breast cancer. Researchers have found evidence that leptin, a biological signal released by adipose tissue that helps regulate appetite, indicating a sense of satiety under normal conditions, may be involved in resistance.
"Leptin is a product of adipose tissue that under normal conditions serves as a sensor of energy reserves and regulates appetite. Leptin levels increase as fat mass increases, and the signals that bind appetite to the reserves The question is: Does all of this leptin circulating under obesity have any effect on the risk or progression of cancer cells? ", explains the researcher.
In their preliminary findings from studies of obese experimental models, the researchers found that leptin was associated with a larger number of cells that start tumors. It has been shown that these cells contribute to initiation, growth, dissemination in the body and resistance to chemotherapy treatments.
On the other hand, the researchers found that a non-steroidal anti-inflammatory drug, "Sulindac", affects several cell signaling pathways related to immune function and the metastatic potential of breast tumors. They did this by mixing diet therapy for obese and non-obese individuals, finding that the treatment had a positive impact on the control of immunosuppression and blocking the pro-metastatic effects of obesity. They believe their findings suggest that the treatment could be helpful in improving outcomes for breast cancer patients.