EMBASE, MEDLINE, SCOPUS, and CINAHL databases were searched from January 1, 1946 to November 4, 2024. Published trials and observational studies reporting the association of sarcopenia and postoperative complications in surgically treated HNC patients were included. Two reviewers independently screened, extracted, and appraised studies using Covidence. Disagreements were resolved through consensus, and/or by consulting a third reviewer. Data were pooled using a random-effects model in RevMan 5.4.1.

Of 6345 screened studies, 17 out of the 23 included studies had outcomes which were incorporated in the meta-analysis (2884 patients from studies between 1996 and 2024). The meta-analysis revealed a statistically significant association between sarcopenia and all postoperative complications (odds ratio (OR) 2.26, 95 % CI [1.54, 3.33], p < 0.0001), postoperative complications grade 3 (OR 2.34, 95 % CI [1.80, 3.03], p < 0.00001), fistula (OR 2.64, 95 % CI [1.68, 4.16], p < 0.0001), and flap complications (OR 2.77, 95 % CI [1.58, 4.85], p = 0.0004). Subgroup analysis revealed the high risk of bias studies did not significantly bias the results (p = 0.76), but the different measurements of sarcopenia contributed significant heterogeneity (p < 0.00001). The level of evidence is moderate, primarily due to publication bias, for all outcomes, as per GRADE.