A new study has provided evidence of a link between an obesity-related gene and breast cancer risk. The study was designed to evaluate expression of the fat mass and obesity associated (FTO) gene in breast tissue and the role of FTO single nucleotide polymorphisms (SNPs) in predicting risk of breast cancer. Obesity has been shown to heighten risk of breast cancer. Genetic variants in the FTO gene have been associated with an increased risk of obesity. SNPs are the most common type of genetic variation among people and most do not influence disease risk.

The study, which was conducted at Northwestern University, included 354 breast cancer cases and 364 cancer-free controls. To examine the role of SNPs of nucleotide sequence 1 of FTO in breast cancer risk, the authors genotyped cases and controls for four SNPs.

The authors showed that FTO is expressed both in normal and cancerous breast tissue. FTO genotypes provided powerful classifiers to predict breast cancer risk. All SNPs were found to be significantly associated with breast cancer risk, however one of the four had the strongest association. Everyone carries the FTO gene, but only 18 percent have this variant of the gene. Carriers have up to a 30 percent greater chance of developing breast cancer. The authors conclude that FTO expression has significance in malignant and normal breast tissue and that FTO SNPs in nucleotide sequence 1 are significantly associated with breast cancer risk. In a separate interview, lead author Virginia Kaklamani commented, “this is a fascinating early finding, which fits with the known connections between obesity and breast cancer.”