New research from the University of Oklahoma suggests that obesity may alter how early breast cancer spreads, potentially explaining why women with obesity face a higher risk of invasive breast cancer. The study, published by the university, reveals unique changes in the bodies of women with obesity that appear to help breast cancer become more aggressive and spread into surrounding breast tissue.
Key Findings
Researchers found higher levels of an enzyme called Sulfatase 2 in tumor cells from women with obesity. This enzyme, which accelerates chemical reactions in the body, has previously been linked to breast, lung, liver, and other cancers. Additionally, the area around the cancer was more inflamed in women with obesity, as immune cells arrived and sped up tumor growth. These immune cells normally fight disease but can be reprogrammed by tumors to support cancer, according to Memorial Sloan Kettering Cancer Center.
Cellular Changes
The study also found that tumor cells in women with obesity appeared better able to survive under stress, and there were differences in both the tumor cells and the surrounding cells. Bethany Hannafon, an assistant professor at the university's College of Medicine, stated, "This could be why women with obesity are at higher risk for invasive breast cancer. The changes that the cancer cells are undergoing are allowing them to survive and thrive."
Implications for Treatment
Although more research is needed, these findings could help doctors better treat patients. Currently, there is no way to determine which women with noninvasive tumors will develop invasive ductal carcinoma, the most common type of invasive breast cancer, accounting for 80% of cases. Invasive lobular carcinoma makes up 10% of cases. Hannafon noted, "Overtreatment is a major concern, but if we had better ways of determining risk, unnecessary treatments could potentially be reduced."
Breast Cancer Statistics
The American Cancer Society estimates that about 321,910 new cases of invasive breast cancer will be diagnosed this year. Breast cancer is the most common cancer in women in the U.S., excluding skin cancers, accounting for about 30% of new female cancers each year. While survival rates have improved over the past 20 years, the number of women diagnosed with invasive breast cancer has not declined.
Obesity and Cancer Risk
Obesity is a known risk factor for invasive breast cancer and other cancers. More than 100 million Americans live with obesity, including about 40% of women. Future research will focus on the role of Sulfatase 2 in invasive breast cancer, with the hope of developing better risk assessment tools.
