Sarcopenia in hepatocellular carcinoma: Current knowledge and future directions

Table 2 Outcomes of hepatocellular carcinoma patients undergoing liver resection (hepatectomy) with sarcopenia over last 5 years

Ref.	Technique	n	Methods and outcomes
Otsuji et al[65] (2015, Japan)	Major hepatectomy and extrahepatic bile resection	256	Total psoas area (TPA) was used to assess sarcopenia. TPA of < 567 mm/m2 for men and < 395 mm/m2 for woman. Length of postoperative hospital stay were longer (39 d vs 30 d, P < 0.001, high rate of liver failure (33% vs 16%), major complications (54% vs 37%), intra-abdominal abscess (29% vs 18% compared to those without sarcopenia (P < 0.05)[69].
Voron et al[110] (2015, Japan)	Hepatectomy	198	L3-SMI used 52.4 cm2/m2 for men and 38.9 cm2/m2 for women. Sarcopenia was associated with shorter median OS (52.3 mo vs 70.3 mo; P = 0.01 and it was an independent predictor of OS and DFS.
Yabusaki et al[111] (2016, Japan)	Primary hepatectomy	195	SMI used 43.75 cm2/m2 for men and 41.10 cm2/m2 for women. Sarcopenia was associated with poor cumulative recurrence rate (P = 0.13).
Takagi et al[113] (2016, Japan)	Curative hepatectomy	254	L3-SMI used 46.4 cm2/m2 for men and 37.6 cm2/m2 for women. The sarcopenic group had a significantly lower 5-yr OS rate than the non-sarcopenic group (58.2% vs 82.4%, P = 0.0002). Further it was an independent predictor of poor survival (HR =2.28, P = 0.002) and poor ASA status (HR = 3.17, P = 0.001).
Kobayashi et al[21] (2019, Japan)	Hepatectomy	465	L3-SMI used. 40.31 cm2/m2 for men and 30.88 cm2/m2 for women. Sarcopenic obesity as a significant risk factor for mortality (HR = 2.504, P = 0.005) and recurrence of HCC (HR = 2.031, P = 0.006) after hepatectomy for HCC.
Hamaguchi et al[112] (2019, Japan)	Hepatectomy	606	L3-SMI was used to assess the sarcopenia. SMI of < 40.31 for men and 30.88 for women were used. A high visceral-to-subcutaneous adipose tissue ratio, low SMI, and high IMAC contributed to an increased risk of death (P < 0.001) and HCC recurrence (P < 0.001) in an additive manner.
Xu et al[22] (2020, China)	Hepatectomy	1420	Authors performed a meta-analysis of six studies and preoperative sarcopenia was significantly associated with poor OS (HR =1.58, 95%CI: 1.34-1.84, P = 0) and shorter DFS (HR =1.54, 95%CI: 1.17-2.02, P = 0.002) in patients with HCC undergoing hepatectomy[24].

Studies, techniques and outcomes to evaluate the success of liver resection in patients with sarcopenia and hepatocellular carcinoma. L3-SMI: Third lumbar vertebrae- skeletal muscle Index; OS: Overall survival; SMI: Skeletal muscle index; HR: Hazards ratio; DFS: Disease free survival. HCC: Hepatocellular carcinoma; TPA: Total psoas area; IMAC: Intramuscular adipose tissue content; PMI: Psoas muscle index.