Skeletal muscle loss and prognosis of breast cancer patients.

PURPOSE: The aim of this study was to clarify the changes in the cross-sectional area of skeletal muscle and muscle attenuation (MA) during 12-month period before death in breast cancer patients.

METHODS: Breast cancer patients who received treatment between September 2002 and July 2014 at Shizuoka Cancer Center or between December 2005 and July 2014 at Teikyo University Hospital were identified. Computed tomography (CT) scans during the 12-month period before death of consecutive female patients who died of breast cancer were reviewed. Skeletal muscle quantity and quality were evaluated by a cross-sectional area of skeletal muscle and MA, respectively, on CT scans taken 10-12 months (T1), 7-9 months (T2), 4-6 months (T3), and within 3 months (T4) prior to death. Wilcoxon signed rank test was used to compare the differences between the two-time points with Bonferroni correction (p = 0.0083).

RESULTS: The medical records of 99 patients (median age at death, 57 years; range, 40-83 years) were retrospectively analyzed. Both the cross-sectional area and MA continued to decrease during 12-month period before death. Statistically significant differences were observed in the cross-sectional areas between T1 and T4 (p = 0.0011), T2 and T4 (p = 0.0019), and T3 and T4 (p = 0.0026), as well as in MA between T2 and T4 (p = 0.0012) and T3 and T4 (p = 0.0061).

CONCLUSIONS: These results suggest that both quantity and quality of the skeletal muscle continued to decrease during 12-month period before death in breast cancer patients.