Body composition CT-derived as predictors of mortality in young women newly diagnosed with breast cancer
Body composition; muscle mass; prognosis; breast cancer.
Introduction
Computed tomography (CT) opportunistically aids in the diagnosis of low muscle mass, a strong predictor of poor prognosis in cancer, particularly in patients with metastatic or non-metastatic breast cancer. However, there is limited evidence to anticipate early deviations in body composition, particularly concerning muscle parameters in young females with this diagnosis.
Objective
To investigate the relationship body composition derived from CT and mortality rates among young women recently diagnosed with breast cancer. Our secondary aim is to identify the best cutoff values associated with this outcome.
Methods
This is a retrospective cohort study involving females newly diagnosed with ductal invasive breast cancer, aged 20 to 40 years. Body composition was assessed using CT scans at the level of the third lumbar vertebra. The outcome of interest was the incidence of mortality. Maximally selected log-rank cox-derived was employed to assess the cutoffs associated with mortality.
Results
This study included 192 women, all prior to any form of treatment, with a median age of 35 years (interquartile range: 31 - 37). Patients were followed up for up to 6 years, during which the incidence of mortality was 12%. Patients who died had significantly lower skeletal muscle mass (SM) and skeletal muscle mass index (SMI). Patients with low muscle mass (SM <94.2 cm2 and SMI <34 cm2/m2) had higher hazard for mortality (adjusted HR: 5.4, 95% CI 2.2 to 15.3, adjusted HR: 2.8, 95% CI 1.1 to 7.5, respectively).
Conclusion
Our study highlights the predictive significance of low muscle mass, as well as the respective cutoff values (SM and SMI) derived from CT scans, which are linked with mortality in a cohort of young women recently diagnosed with breast cancer.