he study at Umeå University, which is published in the journal Cancer Research and Treatment, is the first to investigate how excess body fat and factors relating to insulin resistance, including blood sugar, insulin, and leptin influence the risk of different types of breast cancer. The research team discovered that being overweight and having high blood sugar reduced the risk of lower-risk tumours, but the risk for more aggressive forms of breast cancer increased.
The results were based on data from health screenings of women in Västerbotten County, Sweden, which consisted of 561 women who had been diagnosed with breast cancer several years after the health screening, and 561 women who were free of the disease and who acted as a control.
Tanja Stocks, doctoral candidate at the unit of Urology and Andrology at Umeå University, is the first author of the study. She believes that the connection can be due to that insulin resistance increases the risk for progression of the disease.
“Hopefully now this will lead to work on how things like body fat and blood sugar levels affect the type of tumour that develops, as well as a person’s overall cancer risk,” she said.
The research group behind the study, led by senior Pär Stattin at the unit of Urology and Andrology, Department of Surgical and Perioperative Sciences, Umeå University, found for approximately one year ago a corresponding correlation for prostate cancer. Men with insulin resistance had a lower risk for more treatable tumours but had an increased risk for aggressive cancer, a link that was confirmed in several studies.
Additionally, the research group also has previously found that high blood sugar levels increase the overall risk for cancer, mostly among women. The study was titled “Prospective study of hyperglycaemia and cancer risk” and published in the American journal Diabetes Care, Vol. 30 Number 3 March 2007.
“The most significant conclusion is that one can likely reduce the risk for aggressive cancer by leading a healthy lifestyle to help prevent cardiovascular disease, for example through regular physical activity, weight management and eating in moderation,” said Tanja Stocks.
“The influence of overweight and insulin resistance on breast cancer risk and tumour stage at diagnosis: a prospective study”, Cust AE, Stocks T, Lukanova A, Lundin E, Hallmans G, Kaaks R, Jonsson H, Stattin P. Breast Cancer Research and Treatment, March 2008.