Following a healthy lifestyle could reduce the risk of developing breast cancer for women already at high risk for the disease due to genetic risk and family history. White women at high risk for developing breast cancer who maintained a healthy body mass index, did not drink alcohol, did not smoke, and did not use hormone replacement therapy had approximately the same risk of developing breast cancer as average white women in the United States.1
The average 30-year-old white woman has an estimated 11% chance of developing breast cancer by age 80 years.
This study revealed that approximately 30% of all breast cancer cancer could be prevented by changing known risk behaviors such as decrease alcohol consumption, maintain a healthy body weight, and avoid use of hormone replacements. A larger proportion of this prevention would occur among white women whose risk are greater due to genetic risk and family history.
“People think that their genetic risk for developing cancer is set in stone,” said Nilanjan Chatterjee, PhD, a Bloomberg Distinguished Professor in the Department of Biostatistics at the Bloomberg School, Johns Hopkins University, Baltimore, Maryland, and senior author of the study.
“While you can’t change your genes, this study tells us even people who are at high genetic risk can change their health outlook by making better lifestyle choices such as eating right, exercising, and quitting smoking.”
This study, published in JAMA Oncology, developed a model for predicting the risk for breast cancer by assessing data from more than 17 000 women with breast cancer and almost 20 000 women without the disease from the Breast and Prostate Cancer Cohort Consortium and approximately 6000 female participants in the 2010 National Health Interview Study.
The researchers assessed individual-level data such as age and weight with data on approximately 100 common genetic variants with known, modest associations with breast cancer risk. These variants, which did not include BRCA1 or BRCA2 variants, can result in significantly elevated risk of developing breast cancer when combined.
This information combined with population incidence rates from the Surveillance, Epidemiology, and End Results Program from the National Cancer Institute revealed the effect of healthy lifestyle on mitigating the risk of developing breast cancer.
These results are only applicable to white women. Further studies are needed to elucidate the correlation of genetic variants with the risk of developing breast cancer in other ethnic groups.
1. Maas P, Barrdahl M, Joshi AD, et al. Breast cancer risk from modifiable and nonmodifiable risk factors among white women in the United States [published online May 26, 2016]. JAMA Oncol. doi:10.1001/jamaoncol.2016.1025.