Proportion of esophageal keratinized area ≥ 30% reduces accuracy of preoperative endoscopic evaluation in early esophageal squamous cell carcinoma

Table 1 Comparison of baseline clinical characteristics of early esophageal squamous cell carcinoma with and without esophageal keratosis, n (%)

Variable		Esophageal keratosis (n = 41)	Nonesophageal keratosis (n = 65)	P value
Alcohol consumption history		26 (63.41)	20 (30.77)	0.001
Smoking history		27 (65.85)	22 (33.85)	0.001
Family history		3 (7.32)	6 (9.23)	0.199
Age (year)	> 60	32 (78.05)	38 (58.46)	0.038
	≤ 60	9 (21.95)	27 (41.54)
Sex	Female	8 (19.51)	14 (21.54)	0.802
	Male	33 (80.49)	51 (78.46)

One patient had two independent lesions simultaneously in the middle and lower parts of the esophagus; one of which was early esophageal squamous cell carcinoma with keratinization and the other early nonkeratinizing squamous cell carcinoma. This patient was not included in the statistical comparison of the baseline clinical characteristics between the two groups.

Table 2 Endoscopic data for early esophageal squamous cell carcinoma with and without esophageal keratosis, n (%)

Variable		Esophageal keratosis (n = 46)	Nonesophageal keratosis (n = 75)	P value
Morphology	0-IIa	7 (15.22)	11 (14.67)	0.722
	0-IIb	37 (80.43)	58 (77.33)
	0-IIc	2 (4.35)	6 (8)
Location	Upper thoracic esophagus	2 (4.35)	7 (9.33)	0.561
	Middle thoracic esophagus	21 (45.65)	31 (41.33)
	Lower thoracic esophagus	23 (50)	37 (49.34)
Size (cm)	≥ 2	30 (65.22)	40 (53.33)	0.199
	< 2	16 (34.78)	35 (46.67)

Table 3 Pathological characteristics of early esophageal squamous cell carcinoma with and without esophageal keratosis, n (%)

Variable	Esophageal keratosis (n = 46)	Non-esophageal keratosis (n = 75)	P value
Noninvasive ESCC (65)1	17 (36.96)	48 (64)	0.004
Invasive ESCCs (56)2	29 (63.04)	27 (36)

¹Indicates number of cases of high-grade intraepithelial neoplasia and carcinoma in situ.

²Indicates number of cases of intramucosal and submucosal carcinoma.

ESCC: Esophageal squamous cell carcinoma.

Table 4 Pathological characteristics of invasive esophageal squamous cell carcinoma in early esophageal squamous cell carcinoma with and without esophageal keratosis, n (%)

Variable		Esophageal keratosis (n = 29)	Nonesophageal keratosis (n = 27)	P value
Depth of tumor infiltration	M2	20 (68.97)	10 (37.04)	0.038
	M3	6 (20.69)	8 (29.63)
	SM	3 (10.34)	9 (33.33)
Degree of tumor differentiation	High	19 (65.52)	10 (37.04)	0.086
	Medium-high	8 (27.59)	12 (44.44)
	Medium-low	2 (6.89)	5 (18.52)

Table 5 Preoperative accuracy assessment of early esophageal squamous cell carcinoma with respect to the area of keratosis, n (%)

Variable	Keratosis area ≥ 30% (n = 17)	Keratosis area < 30% (n = 29)	Non-keratosis (n = 75)	P value
Evaluation accuracy (96)1	9 (52.94)	23 (79.31)	64 (85.33)	0.022
Evaluation inaccuracy (25)2	8 (47.06)	6 (20.69)	11 (14.67)

¹Indicates number of cases with consistent preoperative endoscopic diagnosis and postoperative pathological diagnosis.

²Indicates number of cases with different preoperative endoscopic diagnostic and postoperative pathological diagnostic results.

Table 6 Pairwise comparison of evaluation accuracy for early esophageal squamous cell carcinoma with differences in extent of keratosis, n (%)

Variable	Evaluation accuracy		Total (n)	P value
	(+)	(-)
Keratosis area ≥ 30%	9 (52.94)	8 (47.06)	17	0.008
Nonkeratosis	64 (85.33)	11 (14.67)	75
Keratosis area ≥ 30%	9 (52.94)	8 (47.06)	17	0.061
Keratosis area < 30%	23 (79.31)	6 (20.69)	29
Keratosis area < 30%	23 (79.31)	6 (20.69)	29	0.653
Nonkeratosis	64 (85.33)	11 (14.67)	75

Table 7 Comparison of pathological and endoscopic characteristics of lesions in different epithelial keratosis early esophageal squamous cell carcinoma groups, n (%)

Variable		Keratosis area ≥ 30% (n = 17)	Keratosis area < 30% (n = 29)	P value
Noninvasive ESCCs		7 (41.18)	10 (34.48)	0.65
Invasive ESCCs		10 (58.82)	19 (65.52)
Size (cm)	≥ 2	14 (82.35)	16 (55.17)	0.06
	< 2	3 (17.65)	13 (44.83)
Location	Upper thoracic esophagus	1 (5.89)	1 (34.48)	0.91
	Middle thoracic esophagus	7 (41.18)	14 (48.28)
	lower thoracic esophagus	9 (52.94)	14 (48.28)
Morphology	0-IIa	4 (23.53)	3 (10.34)	0.13
	0-IIb	13 (76.47)	24 (82.76)
	0-IIc	0	2 (6.9)

ESCC: Esophageal squamous cell carcinoma.

Table 8 Factors associated with esophageal keratosis in early esophageal squamous cell carcinoma determined by logistic regression analysis

Variable	Wald	OR (95%CI)	P value
Age (> 60/≤ 60 years)	3.137	0.465 (0.199-1.085)	0.077
Infiltration (+/-)	7.464	3.183 (1.387-7.304)	0.006
History of smoking	2.093	0.475 (0.173-1.303)	0.148
History of alcohol consumption	0.356	0.738 (0.272-2.002)	0.551

OR: Odds ratio; CI: Confidence interval.