Purpose: This study aimed to determine the prevalence of sarcopenia and examine whether sarcopenia was associated with overall and breast-cancer-specific mortality in a cohort of women diagnosed with breast cancer (stages I-IIIA).
Methods: A total of 471 breast cancer patients from western Washington State and New Mexico who participated in the prospective Health, Eating, Activity, and Lifestyle Study were included in this study. Appendicular lean mass was measured using dual X-ray absorptiometry scans at study inception, on average, 12 months after diagnosis. Sarcopenia was defined as two standard deviations below the young healthy adult female mean of appendicular lean mass divided by height squared (<5.45 kg/m(2)). Total and breast-cancer-specific mortality data were obtained from Surveillance Epidemiology and End Results registries. Multivariable Cox proportional hazard models assessed the associations between sarcopenia and mortality.
Results: Median follow-up was 9.2 years; 75 women were classified as sarcopenic, and among 92 deaths, 46 were attributed to breast cancer. In multivariable models that included age, race-ethnicity/study site, treatment type, comorbidities, waist circumference, and total body fat percentage, sarcopenia was independently associated with overall mortality (hazard ratio (HR) = 2.86; 95 % CI, 1.67-4.89). Sarcopenic women had increased risk of breast-cancer-specific mortality, although the association was not statistically significant (HR = 1.95, 95 % CI, 0.87-4.35).
Conclusion: Sarcopenia is associated with an increased risk of overall mortality in breast cancer survivors and may be associated with breast-cancer-specific mortality. The development of effective interventions to maintain and/or increase skeletal muscle mass to improve prognosis in breast cancer survivors warrants further study.
Implications for cancer survivors: Such interventions may help breast cancer patients live longer.