Effect of sarcopenic obesity on treatment results in patients with malignant tumors of the gastrointestinal tract: systematic review

Background. Tumors of the gastrointestinal (GI) tract are characterized by high morbidity and poor prognosis. Over the past decade, sarcopenia (skeletal muscle depletion), myosteatosis, sarcopenic obesity were all shown to have negative prognostic effect in patients with various GI malignancies. However, the role of sarcopenic obesity (SO) in patients with GI tumors remains controversial. We have summarized clinical trial data on the effect of SO on treatment results in patients with malignant GI tumors who underwent surgical and/or drug antitumor treatment.Materials and methods. Thisstudy was conducted in comliance with the Preferred Reporting Itemsfor Systematic Review and Meta-Analyses (PRISMA) guidelines. PubMed and Cochrane Library databases were searched for relevant original studies published between January 2009 and December 2022 reporting postoperative complication rate and mortality, long-term survival and chemotherapy toxicity in SO patients with GI cancers.Results. Twenty four studies with 9,601 patients were included. The percentage of SO patients ranged from 2.6 to 51 %. Due to significant heterogeneity of SO determination methods and varying threshold values, the association between SO and outcomes of interest was inconsistent. SO was significantly associated with development of major postoperative complications in six studies. In contrast, three studies did not show any effect of SO on postoperative complications. Only two studies demonstrated that the mortality rate was significantly higher among patients with SO compared to those without SO. Four studies using multivariate analysis showed statistically significant effect of SO on long-term survival, one study – on disease-free survival. However, three trials contradicted this finding and reported that SO was not a negative prognostic factor of long-term survival in GI cancer patients. Three studies investigating SO effect on the outcomes of drug antitumor treatment showed negative effect of SO on chemotherapy toxicity.Conclusion. There is considerable heterogeneity in methods used to define SO in the literature, and current data is limited. Standardized terminology and deeper understanding of sarcopenic obesity pathophysiology is needed to further understand the effect of obesity and sarcopenia on clinical trajectory of patients with GI cancer.