Clinical Impact of Sarcopenia on Gastric Cancer and the Effect of Neoadjuvant Chemotherapy on Sarcopenia

Background: Sarcopenia may adversely affect treatment responses and oncological outcomes in cancer patients. However, the importance of pretreatment nutritional assessment as an indicator of treatment response and outcome in patients with gastric cancer undergoing neoadjuvant chemotherapy remains unclear. Objectives: This study aims to investigate the clinical impact of sarcopenia on gastric cancer and to determine the effect of neoadjuvant chemotherapy (NC) on sarcopenia, as well as body mass index (BMI), psoas muscle index (PMI), and prognostic nutrition index (PNI). Methods: A retrospective review was performed on patients with gastric adenocarcinoma who were operated on after the NC therapy between January 2016 and December 2019. Weight, BMI-, PMI-, and PNI-dependent variables were compared before and after the NC treatment. Sarcopenia was defined according to PMI at the level of the third lumbar vertebra based on computed tomography. Results: Forty-five patients (64.4% women) with a mean age of 56.9±11.2 years were included in the study. After the NC treatment, the mean BMI of the cohort decreased from 26.1±4.3 kg/m2 to 25.1±4.2 kg/m2, the mean PMI decreased from 5.69±1.39 cm2/m2 to 5.16±1.50 cm2/m2, and the mean PNI decreased from 46.6±6.5 to 40.0±7.0 (All, P<0.001). The NC treatment increased the frequency of sarcopenia from 48.9% to 64.5% (P<0.001). According to the Clavien-Dindo (CD) scoring, grade >3 CD complications were more common in the sarcopenic group (27.2%), compared to the non-sarcopenic group (8.7%) (P=0.049). The one-year and three-years overall survival rates were lower in the sarcopenic group (91.7% and 38.2%, respectively), compared to the non-sarcopenic group (93.8% and 45.8%, respectively). However, it was not statistically significant (P=0.509). Conclusion: Sarcopenia is associated with severe postoperative complications in gastric cancer. In addition, the NC treatment reduces PMI, BMI, as well as PNI, and increases sarcopenia frequency. Therefore, patients should be examined in terms of sarcopenia at the time of diagnosis.