Effect of baseline sarcopenia on adjuvant treatment for D2 dissected gastric cancer: Analysis of the ARTIST phase III trial

Background and purpose This study evaluated the clinical significance of preoperative sarcopenia according to adjuvant concurrent chemo-radiotherapy (XP-RT) or chemotherapy alone (XP) in the D2 dissected gastric cancer patient cohort of the ARTIST trial. Materials and methods Skeletal muscles at the L3 vertebra level from preoperative computed tomography images among the ARTIST trial participants were measured using validated in-house software. Skeletal muscle index (SMI) was defined as the measured skeletal muscle area divided by the square of the height, and sarcopenia was defined according to the Korean-specific cutoff, i.e. L3 SMI ≤ 49 cm2/m2 for men and ≤31 cm2/m2 for women. Results Among the 440 patients in whom we were able to evaluate L3 SMI, 75 (17.0%) met the definition for preoperative sarcopenia. No differences in treatment-related toxicities or treatment compliance were observed according to the presence of preoperative sarcopenia in either treatment arm. In the subgroup of patients without preoperative sarcopenia, recurrence was significantly lower in the XP-RT arm than that in the XP arm (p = 0.02). Recurrence-free survival (RFS) was also significantly higher in the XP-RT arm (p = 0.02, hazard ratio 0.633, 95% confidence interval 0.433–0.926) in this subgroup. In the multivariate analysis, and after adjusting for significant prognostic factors, the superior outcome of XP-RT arm regarding RFS was maintained in the subgroup of the patients without preoperative sarcopenia. Conclusions Superior clinical outcomes of adjuvant XP-RT over XP were only observed in patients without preoperative sarcopenia.