Prediction of lymph node metastasis in early esophageal cancer

Table 1 Predictive factors of lymph node metastasis in early esophageal cancer

Category		ESCC	EAC
Imaging	CT	The intrathoracic and abdominal nodes larger than 10 mm in the short axis, supraclavicular nodes greater than 5 mm and retrocrural nodes greater than 6 mm
	EUS	Regional lymph node metastasis: (1) Size greater than 10 mm, (2) a round shape, (3) sharply demarcated borders, and (4) hypoechoic structure
Serum markers		TK1 ≥ 3.38 pmol/L; CYFRA21-1 > 3.30 ng/mL; stathmin-1	NA
		MicroRNA-218
Postoperative pathology and immunohistochemical analysis		Depth of invasion; tumor size; histological differentiation grade; angiolymphatic invasion; neural invasion; expression of PIM-1
		Overexpression of cortactin; the protein levels of mixed-lineage leukaemia 2; the expression of stanniocalcin-1	Transcriptions of CD69, MYD88 and TLR4; low expression of olfactomedin 4

ESCC: Esophageal squamous cell carcinoma; EAC: Esophageal adenocarcinoma; CT: Computed tomography; EUS: Endoscopic ultrasonography; TK1: Thymidine kinase 1; CYFRA21-1: Cytokeratin 19 fragment antigen 21-1; NA: Not available; TLR4: Toll-like receptor 4; MYD88: Myeloid differentiation protein 88.

Table 2 Models predicting lymph node metastasis in early esophageal squamous cell carcinoma

Number	Ref.	Year	Factors	Category	Training set		Validation set
					Cutoff value	C-index (95%CI)	Cutoff value	C-index (95%CI)
1	Jia et al[43]	2016	Depth of invasion and lymphovascular metastasis	Logistic regression model	NA	0.858 (0.757-0.959)	NA	NA
2	Zhou et al[42]	2019	Dumor size, tumor grade, depth of invasion, and angiolymphatic invasion	Logistic regression model	20%	0.80 (0.737-0.862)	20%	0.814 (0.724-0.905)
3				Nomogram	NA	0.80 (0.739-0.856)	NA	0.814 (0.725-0.900)
4	Zheng et al[40]	2018	Depth of tumor invasion, grade of differentiation, tumor size, and lymphovascular invasion	Nomogram	0.142	0.790 (0.717-0.864)	0.224	0.789 (0.709-0.869)
5	Chen et al [39]	2020	Tumor size, histologic grade, invasion depth, lymphovascular invasion, CT-results, and alcohol taking	Logistic regression model	3.735	0.857 (NA)	3.735	0.881 (NA)
6				artificial neural network	NA	0.904 (NA)	NA	0.938 (NA)

C-index: Harrell’s concordance index; CI: Confidence interval; NA: Not available; CT: Computed tomography.