Diagnostic performance of magnifying narrow-band imaging for early gastric cancer: A meta-analysis

Table 1 Characteristics of the selected studies

Ref.	No. of patients	Sex,male/female	Age, mean	Country	Diagnostic standard	Morphology type of lesions (depressed/not depressed)	Lesion size (mm)	Type of assessment	Endoscopic system (Lucera/Exera)	Endoscopists number
Liu et al[19]	90	49/41	57.5	China	Type1 A-E	47/160	NA	Real-time	NA	2
Yao et al[20]	310	183/127	66	Japan	Irregular MV and/or irregular MS with a demarcation line	231/134	NA	Real-time	Lucera	20
Kanesaka et al[21]	49	35/16	NA	Japan	Presence of dense-type crypt openings	0/51	NA	Post-procedure	Lucera	4
Tao et al[4]	508	316/192	63	China	Irregular MV and/or irregular MS with a demarcation line	192/451	7	Post-procedure	NA	NA
Horiuchi et al[22]	51	31/20	65	Japan	Micrification of fine mucosal structure	0/64	NA	Post-procedure	Lucera	NA
Maki et al[5]	93	73/20	NA	Japan	Irregular MV and/or irregular MS with a demarcation line	0/93	NA	Post-procedure	Lucera	NA
Miwa et al[6]	135	77/58	70.1	Japan	Irregular MV and/or irregular MS with a demarcation line	26/109	NA	Post-procedure	Lucera	NA
Tsuji et al[24]	137	101/36	NA	Japan	Irregular MV and/or irregular MS with a demarcation line	19/118	NA	Post-procedure	Lucera	4
Li et al[23]	146	88/58	59.3	China	Type2 A-C	52/112	21.9	Real-time	Lucera	2
Ezoe et al[3]	353	278/75	69	Japan	Irregular MV with a demarcation line	353/0	5.6	Real-time	Lucera	31
Nonaka et al[25]	93	71/22	70	Japan	Type3 I-V	0/93	15.1	Real-time	NA	4
Ezoe et al[7]	53	NA	NA	Japan	Irregular MV with a demarcation line	57/0	≤ 10	Real-time	Lucera	5
Kato et al[8]	111	98/13	66.3	Japan	Disappearance of fine mucosal structure, microvascular dilation, heterogeneity	NA	7.0	Real-time	Lucera	NA
Yao et al[26]	42	NA	NA	Japan	Either WOS with a regular distribution or a regular MV	0/46	NA	Real-time	Lucera	1

¹Type A-E: Type A, short rod-like pits with regular microvasculature inside pits; Type B, elongated open branch-like pits with regular microvasculature; Type C, dilated pits and increased branching microvasculature; Type D, villus-like appearance or light blue crest sign; Type E, the appearance of new tumor vessels;

²Type A-C: Type A, clear regular surface patterns and microvascular architecture; Type B, obscure irregular surface patterns or microvascular architecture; Type C, no surface pattern and sparse microvessels or with avascular areas;

³Type I-V: Type I, clear MS, unclear MV; type II, clear MS, clear MV; type III, clear MS, abnormal MV; type IV, slightly obscured MS, abnormal MV; type V, markedly obscured MS, abnormal MV. NA: Not available; MV: The microvascular pattern; MS: The microsurface pattern; WOS: White opaque substance.

Table 2 Quality of articles using the quality assessment of diagnostic accuracy studies tool

Ref.	Item 1	Item 2	Item 3	Item 4	Item 5	Item 6	Item 7	Item 8	Item 9	Item 10	Item 11	Item 12	Item 13	Item 14	Scores
Liu et al[19]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	14
Yao et al[20]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	14
Kanesaka et al[21]	N	Y	Y	Y	Y	Y	Y	Y	Y	U	Y	Y	Y	Y	12
Tao et al[4]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	U	Y	Y	Y	13
Horiuchi et al[22]	Y	Y	Y	Y	Y	Y	Y	Y	Y	U	U	Y	Y	Y	12
Maki et al[5]	Y	Y	Y	Y	Y	Y	Y	Y	Y	U	U	Y	Y	Y	12
Miwa et al[6]	Y	Y	Y	Y	Y	Y	Y	Y	Y	U	U	Y	Y	Y	12
Tsuji et al[24]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	14
Li et al[23]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	14
Ezoe et al[3]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	U	Y	Y	N	12
Nonaka et al[25]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	14
Ezoe et al[7]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	U	Y	Y	Y	13
Kato et al[8]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	13
Yao et al[26]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	U	Y	Y	13

Item 1: Was the spectrum of patients representative of the patients who will receive the test in practice? Item 2: Were selection criteria clearly described? Item 3: Is the reference standard likely to correctly classify the target condition? Item 4: Is the time period between reference standard and index test short enough to be reasonably sure that the target condition did not change between the two tests? Item 5: Did the whole sample or a random selection of the sample receive verification by using a reference standard of diagnosis? Item 6: Did patients receive the same reference standard regardless of the index test result? Item 7: Was the reference standard independent of the index test? Item 8: Was the execution of the index test described in sufficient detail to permit replication of the test? Item 9: Was the execution of the reference standard described in sufficient detail to permit its replication? Item 10: Were the index test results interpreted without knowledge of the results of the reference standard? Item 11: Were the reference standard results interpreted without knowledge of the results of the index test? Item 12: Were the same clinical data available when test results were interpreted as would be available when the test is used in practice? Item 13: Were uninterpretable/intermediate test results reported? Item 14: Were withdrawals from the study explained? Y: Yes; N: No; U: Unclear.

Table 3 Subgroup analysis on diagnostic performance of magnifying endoscopy with narrow-band imaging for differentiating early gastric cancer from non-cancer

	Number of studies (lesions examined)	Sensitivity (95%CI)	Specificity (95%CI)	AUC	I2
					Sensitivity	Specificity
Overall	14 (2433)	0.86 (0.83-0.89)	0.96 (0.95-0.97)	0.9623	75.4%	86.9%
Type of lesion
Depressed	3 (605)	0.64 (0.52-0.75)	0.96 (0.95-0.98)	0.7877	0.0%	74.1%
Not depressed	10 (1828)	0.90 (0.86-0.92)	0.96 (0.95-0.97)	0.9694	64.9%	90.1%
Diagnosis standard
Diagnosis (IMVP/IMSP + DL)	7 (1613)	0.81 (0.76-0.85)	0.97 (0.96-0.98)	0.9407	78.0%	88.8%
Diagnosis (others)	7 (820)	0.93 (0.89-0.96)	0.93 (0.91-0.95)	0.9719	36.6%	80.5%
Lesion size
Diameter (> 10 mm)	8 (777)	0.90 (0.86-0.93)	0.88 (0.85-0.91)	0.9585	71.2%	44.7%
Diameter ( ≤ 10 mm)	5 (1449)	0.74 (0.65-0.82)	0.98 (0.97-0.98)	0.9458	67.1%	86.6%
Sample size
≥ 100 patients	8 (2035)	0.84 (0.79-0.88)	0.97 (0.96-0.97)	0.9663	79.1%	90.7%
< 100 patients	6 (398)	0.90 (0.85-0.93)	0.87 (0.81-0.92)	0.9422	67.3%	0.0%
Type of assessment
Real-time	8 (1310)	0.85 (0.81-0.90)	0.95 (0.94-0.96)	0.9617	81.6%	81.2%
Post-procedure	6 (1123)	0.87 (0.82-0.91)	0.97 (0.95-0.98)	0.9608	65.5%	91.6%
Country
China	3 (1014)	0.94 (0.88-0.97)	0.98 (0.97-0.99)	0.9864	62.5%	95.7%
Japan	11 (1419)	0.84 (0.80-0.88)	0.94 (0.92-0.95)	0.9526	74.6%	71.2%

I² > 50% was considered significant for heterogeneity. AUC: Area under the curve.