Abstract
BACKGROUND: Sarcopenia has been associated with adverse outcomes in numerous malignancies. The prevalence and prognostic significance of sarcopenia in patients with breast cancer receiving neoadjuvant chemotherapy (NAC) is uncertain. This study assessed the prevalence and effect of sarcopenia on the response to NAC, as well as on operative and oncological outcomes. METHODS: Consecutive patients with breast cancer receiving NAC with curative intent between 2010 and 2015 at a single tertiary referral centre were included. Lean body mass and skeletal muscle index (SMI) were determined by analysing axial computed tomography scans taken at L3, with sarcopenia defined as SMI < 38.5cm2/m2. Univariable and multivariable linear, logistic, and Cox proportional hazards regression analyses were performed. RESULTS: Among 258 patients (mean age 49.5 (SD11.1) years and BMI 27.6(5.7) kg/m2), 24 (12.2%) exhibited sarcopenia. Sarcopenia was not associated with molecular subtype (P = 0.746) nor clinical tumour size (P = 0.960). On multivariable analysis, sarcopenia did not predict complete pathological response (P = 0.069), nodal positivity after NAC (P = 0.442), or Sataloff tumour response to NAC (P = 0.898). Sarcopenia did not predict the length of hospital stay (P = 0.716) nor the Comprehensive Complication Index (P = 0.242) after surgery. Lower lean body mass independently predicted overall survival (hazard ratio (HR) 0.92; 95% confidence interval [c.i.] 0.85 to 0.99; P = 0.028) and invasive disease-free survival (HR 0.93; 95% c.i. 0.87 to 1.00; P = 0.049), but not disease-specific survival (P = 0.070). CONCLUSION: Sarcopenia was not associated with clinicopathological parameters and did not affect the response to NAC nor postoperative complications. Lower lean body mass was associated with reduced overall and invasive disease-free survival in patients with breast cancer receiving NAC.