Table 1.

The characteristics of the included studies.

Study	Type of study	Patients (n)	Inclusion criteria	Exclusion criteria	Sarcopenia definition
Ida et al (2015)22	Prospective	138	Oesophageal squamous cell carcinoma; oesophagectomy	N/A	Values below < 90% of standard (bioelectrical impedance)
Harada et al (2016)21	Retrospective	256	Squamous cell carcinoma; patients underwent surgical resection (2005–2011), CT available	Patients with an interrupted CRT history; patients receiving palliative CRT; palliative care	Muscle area normalised by the square of the height (m2); cut off: (tertile 3) < 44.5cm2/m2 for men, < 36.5cm2/m2 for women
Tamandl et al (2016)13	Retrospective	200	Oesophageal/gastro-oesophageal cancer; potentially curative surgery; suitability for analysis of sarcopenia and body composition parameters	Metastatic or no resection; CT images not retrievable/not complete; abdominal examination covering lumbar vertebra 3; no malignancy upon histology	SMI (cm2/m2) = TMA at L3/(height [m] × height [m]). Sarcopenia was defined: SMI of ≤ 39cm2/m2 for women and ≤ 55cm2/m2 for men
Grotenhuis et al (2016)14	Retrospective	120	Oesophagectomy for cancer after neoadjuvant chemoradiotherapy; patients with a CT performed not less than 3 months before initial diagnosis of oesophageal cancer, before start of nCRT	N/A	Total cross-sectional muscle tissue measured transversely at the third lumbar level < 52.4cm2/m2 body surface area for men, < 38.5cm2/m2 body surface area for women (SMI-CT)
Makiura et al (2016)23	Retrospective	104	Patients with oesophageal cancer scheduled to undergo definitive oesophagectomy (2011–2015); preoperative assessment	Recurrent cancer; declined to consent	Low muscle mass and strength and/or low physical performance. Low muscle mass was defined by appendicular SMM ÷ squared height of < 7.0kg/m2 for men and < 5.7kg/m2 for women (bioelectrical impedance). Low muscle strength was defined by handgrip strength of < 26kg for men and < 18kg for women. Low physical performance was defined by gait speed of < 0.8metres/second
Nishigori et al (2016)25	Retrospective	199	Histological diagnosis of thoracic oesophageal cancer; patients underwent oesophagectomy followed by primary reconstruction (2005–2014)	Preoperative CT not available; preoperative chemoradiotherapy; multiple primary cancers	SMM at L3 level was normalised to patient’s height to calculate SMI-CT (cm2/m2). Cut-off sarcopenia: 52.4cm2/m2 for men and 38.5cm2/m2 for women
Paireder et al (2016)26	Retrospective	130	Consecutive patients who underwent oesophageal resection for oesophageal cancer (2006–2013); neoadjuvant treatment	Missing pre- or post-therapeutic CT	SMI-CT calculated as TMA/height (m) × height (m). Sarcopenia defined as a reduced SMI of ≤ 39cm2/m2 for women and ≤ 55cm2/m2 for men
Nakashima et al (2018)24	Retrospective	341	Consecutive patients who underwent oesophagectomy for oesophageal cancer (2004–2014)	Data not available from preoperative CT	Oesophageal cancer-specific assessment for sarcopenia, median SMI as cut-off values by sex: 47.24cm2/m2 in men and 36.92cm2/m2 in women SMI (cm2/m2) CT

CT, computed tomography; N/A, not available; nCRT, neo-adjuvant chemoradiotherapy; SMI, skeletal muscle index; SMM, skeletal muscle mass; TMA, total muscle area.