Table 1.

Summary of studies evaluating the impact of muscle on breast cancer outcomes

Author, year	Population	Measures	Outcome
Sheehan et al. [20]	Retrospective Stage IV, ER negative n = 152	CT scan Sarcopenia (SMI ≤ 41 cm2/m2) Low SMD (< 41 HU, < 33 HU if BMI ≥ 25)	Sarcopenia at diagnosis not associated with OS. Low SMD reduced 2 year OS, HR 1.72 (1.09–2.72)
Caan et al. [21]	Retrospective Stage II, III n = 3241	CT scan Sarcopenia (SMI < 40 cm2/m2) Low SMD (< 37.8 HU)	Sarcopenia associated with OS, HR 1.41 (95% CI 1.18–1.69) SMD not associated with OS
Deluche et al. [22]	Retrospective Stage I–III n = 119	CT scan Sarcopenia (SMI < 41 cm2/m2)	Absence of sarcopenia associated with better DFS (HR 0.3, 95% CI 0.1–0.8, p = 0.02) and OS (HR 0.3, 95% CI 0.1–0.99, p = 0.05)
Shachar et al. [23]	Retrospective Stage IV, taxane chemotherapy n = 40	CT scan Sarcopenia (SMI < 41 cm2/m2)	Sarcopenia associated with higher grade 3–4 toxicity (18% vs. 57%, p = 0.02). No association with survival
Rier et al. [24]	Retrospective Stage IV, first line chemotherapy n = 166	CT scan Sarcopenia (SMI < 41 cm2/m2) Low SMD (< 41 HU, < 33 HU if BMI ≥ 25)	Low SMD associated with lower OS (HR 2.04, 95% CI 1.34–3.12, p = 0.001). SMI had no association with OS
Villasenor et al. [25]	Prospective Stage 0–III n = 471	DEXA scan Sarcopenia (SMI < 5.45 kg/m2)	Sarcopenia associated with OS (HR 2.86, 95% CI 1.67–4.89)
Prado et al. [26]	Retrospective Stage IV, capecitabine chemotherapy n = 55	CT scan Sarcopenia (SMI < 38.5 cm2/m2) Low SMD (< 41 HU, < 33 HU if BMI ≥ 25)	Sarcopenia associated with grade 3–4 toxicity (20% vs. 50%, p = 0.03) and shorter TTP (173 vs 101 days, p = 0.05)

CT computed tomography, SMI skeletal muscle index, SMD skeletal muscle density, HU Hounsfield units, OS overall survival, HR hazard ratio, DFS disease free survival, TTP time to progression