Diagnostic accuracy of stereomicroscopy assessment of invasion depth in ex vivo specimens of early gastric cancer

Table 1 Clinicopathological features of the 854 patients and their lesions, n (%)

Variables	854 patients
Sex
Male	627 (73.4)
Female	227 (26.6)
Age, mean ± SD, years	62.0 ± 9.8
Location
Upper1	233 (27.2)
Middle2	279 (32.7)
Lower3	325 (38.1)
Residual stomach	17 (2.0)
Macroscopic type
Type 0-I	51 (6.0)
Type 0-IIa	362 (42.4)
Type 0-IIb	39 (4.6)
Type 0-IIc	390 (45.6)
Type 0-III	12 (1.4)
Tumor size (mm)
≤ 20	508 (59.5)
21-30	207 (24.2)
> 31	139 (16.3)
Ulceration
(−)	567 (66.4)
(+)	287 (33.6)
Histopathological type
Differentiated	704 (82.4)
Undifferentiated	150 (17.6)
Horizontal margin
(−)	830 (97.2)
(+)	24 (2.8)
Vertical margin
(−)	790 (92.5)
(+)	64 (7.5)

¹Upper third of the stomach consisting of cardia and upper body.

²Middle third of the stomach consisting of angle and middle body.

³Lower third of the stomach consisting of pylorus, antrum, and lower body.

Table 2 Accuracy of stereomicroscopy diagnose the invasion depth in early gastric cancers, %

Stereomicroscopy diagnosis	Pathological stage		Accuracy	Sensitivity	Specificity	PPV	NPV
	T1a	T1b
Ulceration absent	NA	NA	93.5	95.0	86.9	96.9	80.2
M	437	14	NA	NA	NA	NA	NA
SM	23	93	NA	NA	NA	NA	NA
Ulceration present	NA	NA	35.8	19.1	95.2	93.5	24.8
M	42	3	NA	NA	NA	NA	NA
SM	182	60	NA	NA	NA	NA	NA

PPV: Positive predictive value; NPV: Negative predictive value; NA: Not applicable; M: Mucosa; SM: Submucosa.

Table 3 Clinicopathological features of patients with gastric cancer accurately diagnosed and misdiagnosed by stereomicroscopy, n (%)

Factors	Stereomicroscopy diagnosis		P value
	Accurately, n = 632	Misdiagnosed, n = 222
Location
Upper	168 (72.1)	5 (27.9)	0.113
Middle	196 (70.3)	83 (29.7)
Lower	255 (78.5)	70 (21.5)
Residual stomach	13 (76.5)	4 (23.5)
Macroscopic type
Type 0-I	42 (82.4)	9 (17.6)	0.179
Type 0-IIa	276 (76.2)	86 (23.8)
Type 0-IIb	30 (76.9)	9 (23.1)
Type 0-IIc	277 (71.0)	113 (29.0)
Type 0-III	7 (58.3)	5 (41.7)
Tumor size (mm)
≤ 20	404 (79.5)	104 (20.5)	< 0.001
21-30	138 (66.7)	69 (33.3)
> 31	90 (64.7)	49 (35.3)
Ulceration
(−)	530 (93.5)	37 (6.5)	< 0.001
(+)	102 (35.5)	185 (64.5)
Histopathological
Differentiated	518 (73.7)	185 (26.3)	0.645
Undifferentiated	114 (75.5)	37 (24.5)
Horizontal margin
(−)	613 (73.9)	217 (26.1)	0.559
(+)	19 (79.2)	5 (20.8)
Vertical margin
(−)	573 (72.5)	217 (27.5)	< 0.001
(+)	59 (92.2)	5 (7.8)

Table 4 Multivariate analysis of risk factors misdiagnosed by stereomicroscopy

Factors	Odds ratio	95%CI	P value
Location
Middle	1	Reference
Upper	0.9	0.622-1.342	0.645
Lower	0.6	0.448-0.937	0.021
Residual stomach	0.7	0.230-2.294	0.586
Macroscopic type
Type 0-I	1	Reference
Type 0-IIa	0.4	0.173-1.122	0.086
Type 0-IIb	0.4	0.11-1.681	2.225
Type 0-IIc	0.5	0.189-1.218	0.122
Type 0-III	0.2	0.044-1.022	0.053
Tumor size (mm)
≤ 20	1	Reference
21-30	1.6	1.011-2.695	0.045
≥ 31	1.5	0.826-2.575	0.193
Ulceration
(−)	1	Reference
(+)	36.1	22.728-57.40	< 0.001
Histopathological
Differentiated	1	Reference
Undifferentiated	0.7	0.417-1.345	0.333
Horizontal margin
(−)	1	Reference
(+)	0.7	0.186-2.742	0.624
Vertical margin
(−)	1	Reference
(+)	0.1	0.025-0.221	< 0.001