Obesity Increases DNA Damage Among Patients with BRCA Mutations

Overweight patients with BRCA mutations may be more likely to develop breast cancer.

The link between obesity and cancer has been well-established; however, despite this fact, many individuals globally do not maintain a healthy weight.

Patients with BRCA gene mutations who have a high body mass index (BMI) may have a higher level of DNA damage in normal breast gland cells, according to a study presented at ENDO 2018.

Both obesity and BRCA mutations are known to increase the risk for breast cancer. Previous research suggests that breast cancer is more common among patients with BRCA mutations who are obese, according to the session.

"These data show for the first time that obesity is associated with increased DNA damage in breast epithelium of BRCA mutation carriers," said lead author Priya Bhardwaj.

Included in the study were breast tissue samples from 82 patients with BRCA mutations. The authors used immunofluorescence to stain the gamma-H2AX foci to analyze normal breast epithelium for DNA damage.

Next, the researchers counted the number of foci, which occur due to DNA damage.

Upon examination, there was a positive link between BMI and occurrence of gamma-H2AX foci in breast gland cells, according to the study.

"Women who carry a mutation in BRCA genes have an increased risk of developing breast and ovarian cancer,” said principal investigator Kristy A. Brown, PhD. “Obesity is a well-established risk factor for breast cancer in the general population and some studies suggest that maintaining a healthy lifestyle by exercising or avoiding obesity may decrease the likelihood of developing cancer in BRCA mutation carriers."

These findings underscore the importance of maintaining a healthy weight, especially among patients with BRCA mutations.

The authors note that the results may have serious implications due to the high prevalence of obesity among Americans.

"This research provides biological evidence for cells of the breast being susceptible to the effects of obesity," Dr Brown said. "Maintaining a healthy weight may be associated with a decreased likelihood of developing breast cancer by limiting the amount of DNA damage in the breast glands."

A recent Vital Signs report from the CDC indicates that overweight and obesity are linked to an increased risk of 13 common types of cancers—including breast cancer—that account for 40% of cases diagnosed in 2014.