Diagnostic value of endothelial markers and HHV-8 staining in gastrointestinal Kaposi sarcoma and its difference in endoscopic tumor staging

Table 1 Definitive diagnosis of gastrointestinal lesion from endoscopic biopsy samples (n = 103) n (%)

Diagnosis	No.
GI-KS	84
Upper GI tract	57 (67.9)
Esophagus	7 (8.3)
Stomach	38 (45.2)
Duodenum	12 (14.3)
Lower GI tract	27 (32.1)
Cecum	8 (9.5)
Ascending colon	1 (1.2)
Transverse colon	2 (2.4)
Descending colon	1 (1.2)
Sigmoid colon	7 (8.3)
Rectum	8 (9.5)
Non-KS lesion	19
Hyperplastic polyp	8
Fundic gland polyps	1
Helicobacter-associated gastritis	1
Malignant lymphoma	4
Anorectal condyloma	2
Non-specific colitis	3

GI-KS: Gastrointestinal Kaposi sarcoma.

Table 2 Diagnostic value of endoscopic biopsy in gastrointestinal Kaposi sarcoma (n = 103)

KS/non-KS (84/19)	Sensitivity, % (95%CI)	Specificity, % (95%CI)	Positive LR (95%CI)	Negative LR (95%CI)	ROC area1 (95%CI)
HE	70.2 (59.3-79.7)	94.7 (74.0-99.9)	9.33 (1.99-43.8)2	0.32 (0.23-0.46)2	0.83 (0.75-0.90)
(59/1)
D2-40	77.4 (67.0-85.8)	100 (82.4-100)	30.8 (1.99-477)2	0.24 (0.16-0.35)2	0.89 (0.84-0.93)a
(65/0)
Blood vessel marker	81 (70.9- 88.7)	78.9 (54.4- 93.9)	3.85 (1.6-9.24)	0.24 (0.15-0.40)	0.80 (0.70-0.90)
(68/4)
HHV-8	63.1 (51.9-73.4)	100 (82.4-100)	25.2 (1.62-391)2	0.38 (0.29-0.51)2	0.82 (0.76-0.87)
(53/0)

LR: Likelihood ratio; HE: Hematoxylin and eosin; HHV: Human herpesvirus.

¹Receiver operating characteristic (ROC) area is significantly (P < 0.01) different in this category;

²LR estimated using the substitution formula. A value of 0.5 was added to all cell frequencies before calculation;

^aP < 0.05 for comparisons of lesions by HE staining.

Table 3 Diagnostic values of gastrointestinal Kaposi sarcoma in relation to size, location, and macroscopic appearances on endoscopy (n = 103)

Subgroup	Specific stain	No. of lesions (KS/non-KS)	ROC-AUC (95%CI)	P value1
Size	Size < 10 mm	26/7
	HE	14/0	0.77 (0.67-0.87)
	D2-40	16/0	0.81 (0.71-0.90)
	Blood vessel marker	18/4	0.56 (0.34-0.78)
	HHV-8	10/0	0.69 (0.60-0.79)	< 0.05
	Size > 10 mm	58/12
	HE	45/1	0.85 (0.75-0.94)
	D2-40	49/0	0.92 (0.88-0.97)
	Blood vessel marker	50/0	0.93 (0.89-0.98)
	HHV-8	43/0	0.93 (0.89-0.98)	< 0.01
Location	Upper GI tract	57/9
	HE	36/0	0.82 (0.75-0.88)
	D2-40	42/0	0.87 (0.81-0.93)a
	Blood vessel marker	44/4	0.66 (0.48-0.84)
	HHV-8	36/0	0.82 (0.75-0.88)	< 0.01
	Lower GI tract	27/10
	HE	23/1	0.88 (0.76-1.00)
	D2-40	23/0	0.93 (0.86-0.99)
	Blood vessel marker	24/0	0.94 (0.88-1.00)
	HHV-8	17/0	0.82 (0.72-0.91)	< 0.01
Macroscopic appearance	Patches	23/4
	HE	12/1	0.64 (0.37-0.90)
	D2-40	14/0	0.80 (0.70-0.91)
	Blood vessel marker	15/0	0.83 (0.73-0.93)
	HHV-8	8/0	0.67 (0.57-0.77)	< 0.01
	Polypoid	9/3
	HE	5/0	0.78 (0.61-0.95)
	D2-40	8/0	0.94 (0.84-1.00)a
	Blood vessel marker	8/3	0.44 (0.34-0.55)a
	HHV-8	4/0	0.72 (0.55-0.89)	< 0.01
	SMT	37/7
	HE	32/0	0.93 (0.88-0.99)
	D2-40	33/0	0.95 (0.90-0.10)
	Blood vessel marker	33/1	0.88 (0.73-1.00)
	HHV-8	30/0	0.91 (0.84-0.97)	0.15
	SMT with ulcer	15/5
	HE	10/0	0.83 (0.71-0.96)
	D2-40	10/0	0.83 (0.71-0.96)
	Blood vessel marker	12/0	0.90 (0.80-1.00)
	HHV-8	11/0	0.87 (0.75-0.98)	0.34

¹P values of receiver operating characteristic (ROC) area in each category were compared.

^aP < 0.05 for the comparison with lesions by hematoxylin and eosin (HE) staining. GI-KS: Gastrointestinal Kaposi sarcoma; ROC-AUC: ROC area under the curve; SMT: Submucosal tumor.