Prognostic significance of sarcopenia in metastatic esophageal squamous cell carcinoma.

Abstract

4068 Background: Sarcopenia is defined as low skeletal muscle mass and represents a quantifiable marker of frailty. Disease related symptoms of anorexia, nausea and dysphagia, in addition to reduced physical activity contribute to muscle wasting in metastatic esophageal squamous cell cancer (MESCC) patients. This study set out to evaluate the prognostic utility of sarcopenia and its association with nutritional indices. Methods: MESCC patients (pts) with available abdominal CT imaging, attending Princess Margaret Cancer Centre between 2011 and 2016, were identified from the institutional database. Skeletal muscle index (SMI), normalized by height, was calculated at the third lumbar (L3) vertebra using SliceOMatic software. SMI cutoffs for sarcopenia were 34.4cm2/m2 in females and 45.4cm2/m2 in males based on previously established consensus. Nutritional risk index (NRI) was calculated using weight and albumin with malnutrition defined as < 97.5. Results: Of the 58 pts analyzed, 26 presented with de novo MESCC, median age was 64 (range 48-85), 30 pts were ECOG PS ≤1 and 45% received systemic therapy. 93% of pts experienced weight loss > 5% in the 3 months preceding diagnosis and median BMI was 20.4 (range 16.3-34.9). Twenty-four (41%) pts were sarcopenic (SP) with differences in BMI and NRI (p < 0.05) compared to non-sarcopenic (NSP) pts. Median BMI in SP pts was 18.9 (16.3-25.6), 46% had a BMI < 18.5 and none were obese (BMI ≥ 30). By NRI, 58% of SP pts were malnourished. Males comprised 71% of SP pts (p = 0.03) but no difference from NSP MESCC pts was identified with age, race, ECOG PS or smoking status with univariate analysis. Median overall survival (OS) was 6 months; 4.2 in SP pts and 6.2 in NSP pts. Significant difference was identified with NRI (p = .0.009) but not sarcopenia (p = 0.247) or BMI (p = 0.393). With a multi-variate Cox model for NRI and sarcopenia, including age, sex, race, and ECOG PS, only ECOG PS was a significant predictor of mortality, HR for 2-3 vs 0-1 of 5.4 (2.5-11.9) p < 0.001. Conclusions: Sarcopenia at diagnosis was not associated with OS. NRI was superior to BMI alone with respect to discriminating pt outcomes, however ECOG PS was the only measure significantly associated with survival.