A genetic predisposition toward higher body weight is linked to a 15% increased risk of death from any cause among breast cancer survivors, according to long-term data. The study of over 4,000 women with nonmetastatic breast cancer suggests inherited susceptibility to a higher body mass index can negatively impact survival outcomes.
The research focused on postmenopausal women diagnosed with breast cancer between 1992 and 2017. Investigators developed a polygenic score for body mass index using genetic data. They then tracked deaths through 2020.
Survivors with the highest genetic predisposition scores were more likely to have a body mass index of 30 or greater. Over a median follow-up of 14.5 years, those with the highest genetic predisposition faced a 15% increased risk of all-cause mortality compared to those with the lowest predisposition.
Crucially, higher levels of physical activity, specifically walking, were needed to offset this genetic risk. Women with the highest genetic predisposition required approximately 1.7 hours more walking per week to achieve a similar mortality risk as those with the lowest predisposition - roughly an additional 15 minutes daily.
These findings highlight how genetic susceptibility to excess body weight contributes to survival differences in breast cancer survivors. Incorporating genetic risk into lifestyle counseling could lead to more personalized recommendations, particularly regarding physical activity, to lower long-term mortality risk.