A new study has reported that the fat hormones leptin and adiponectin both can play a role in breast cancer development. The authors examined in situ ductal carcinoma, invasive ductal breast cancer, and non-cancerous adjacent tissue and observed the presence of leptin and adiponectin receptors. Related mRNA expression was also detected in hormone receptor positive MCF-7 human breast cancer cells. Importantly, leptin mRNA expression was 34.7 times higher than adiponectin mRNA expression in the cancer cells. Adiponectin treatment was found to reduce proliferation of the MCF-7 cells, whereas leptin stimulated their growth. Leptin was also observed to induce progesterone receptor mRNA expression. The authors conclude that leptin stimulates MCF-7 breast cancer cell proliferations whereas adiponectin suppresses it.

Previous studies have reported leptin-breast cancer connection

This study helps explain other reports that women with breast cancer tend to have low serum adiponectin levels and high serum leptin levels. Both alcohol consumption and the insulin resistance found in metabolic syndrome have been shown to increase leptin levels, which might partially explain the roles of alcohol and being overweight in increasing the risk of breast cancer.