Walking May Reduce Obesity-Related Mortality Risk in Breast Cancer: Study

A new study published in the Journal of American Medical Association showed that the chance of mortality is greater for breast cancer (BC) patients with a higher hereditary risk for obesity.

The prognosis of breast cancer is influenced by metabolic, hormonal, and inflammatory pathways that are influenced by genetic vulnerability to obesity. Recent data indicates that treatment response and survival may be impacted by an inherent propensity for increased body weight. Comprehending this correlation may enhance risk assessment and provide tailored survival treatment for impacted women. This study examined the potential correlation between BC survivors' risk of death and a hereditary propensity to high body weight.

The participants in this cohort study participated in a survey in 1992 and in follow-up surveys conducted every two years beginning in 1997 as part of the Cancer Prevention Study–II Nutrition Cohort, a sizable study. Adults from 21 US states make up the cohort. This study included women with genetic data who were diagnosed with a first primary nonmetastatic BC between 1992 and 2017.

Only postmenopausal women with genetically confirmed European ancestry at the time of cancer diagnosis were included in the analyses. The period of data analysis was July 2023–July 2025. A meta-analysis of genome-wide association studies involving over 700,000 people revealed 941 single nucleotide variations, which were used to calculate the polygenic score for body mass index (BMI-PGS).

4177 women having a BC diagnosis were included in this investigation. 71.5 years was the median (IQR) age at diagnosis. When compared to survivors in the lowest tertile, BC survivors with BMI-PGS in the top tertile were more likely to have a BMI of 30 or above. The median (IQR) follow-up period was 14.5 years, during which 2114 BC survivors (50.6%) passed away. The risk of all-cause death was 15% higher for BC survivors in the highest tertile of the BMI-PGS than for those in the lowest tertile.

To be at the same risk level as BC survivors in the lowest tertile of the BMI-PGS, BC survivors with the highest tertile of the BMI-PGS had to walk an additional 1.7 hours per week, or around 15 minutes more every day of the week. Overall, all-cause mortality was greater among BC survivors who were genetically inclined to have a higher BMI. 

Source:

Bodelon, C., Landry, M., Lori, A., Hodge, J. M., Choudhury, P. P., Rees-Punia, E., Wang, Y., McCullough, L. E., Patel, A. V., & Teras, L. R. (2026). Genetic predisposition to excess body weight and survival in women diagnosed with breast cancer. JAMA Network Open, 9(1), e2553687. https://doi.org/10.1001/jamanetworkopen.2025.53687