The study selection process is summarized in Fig. 1. A total of 236 potentially relevant records were initially identified from the three databases searched and screening of citations of related articles, with 88 duplicates removed. Screening of titles and abstracts resulted in the exclusion of 109 articles that did not meet the objectives of the meta-analysis. The full texts of the remaining 39 articles were independently reviewed by two authors, leading to the exclusion of 15 studies for various reasons detailed in Fig. 1. Ultimately, 24 studies were included in the quantitative analysis [19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42].

Flowchart of database search and study inclusion

Table 1 shows the summarized characteristics of the available studies included in the meta-analysis. Overall, 24 retrospective cohorts, published between 2015 and 2025, and performed in Japan, Indonesia, Korea, German, China, Italy, and Thailand, were involved in the meta-analysis [19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42]. A total of 7436 patients with HCC were included in these studies. The mean ages of the patients varied from 50.0 to 74.0 years, and the proportion of men varied from 65.9 to 100.0%. The main anticancer treatments were surgical resection in seven studies [20, 21, 23, 27, 28, 35, 39], liver transplant in two studies [30, 32], TACE or transarterial embolization (TAE) in four studies [22, 25, 38, 42], immunotherapy in four studies [24, 26, 31, 33], and TKIs in five studies [29, 34, 36, 40, 41]. The main anticancer treatments were not specified in one study [19], and a comprehensive treatment involving TACE, RFA, surgical resection, chemoradiotherapy, and supportive treatment was used in another study [37]. All the included studies evaluated myosteatosis using CT imaging at the level of the third lumbar vertebra except one study [41], in which the MRI imaging at the same level was used. Myosteatosis was evaluated using IMAC in six studies [20, 21, 27, 28, 35, 38] and using SMD in the other 18 studies [19, 22,23,24,25,26, 29,30,31,32,33,34, 36, 37, 39,40,41,42]. A sex-specified cutoff for the diagnosis of myosteatosis was used in 11 studies [19,20,21,22, 25, 27, 32, 33, 35, 38, 42], and a universal cutoff was used in the other 13 studies [23, 24, 26, 28,29,