Risk factors for tuberculosis after gastrectomy in gastric cancer

Table 1 Baseline characteristics of gastrectomy patients

Characteristic	Total(n = 1776)	No active TB(n = 1760)	Active TB(n = 16)	P value
Age (yr)	58 (20-89)	58 (20-89)	54 (40-83)	0.395
< 40	169 (9.5)	168 (9.5)	1 (6.3)
41-60	843 (47.5)	834 (47.4)	9 (56.3)
61-80	743 (41.8)	738 (41.9)	5 (31.3)
> 80	21 (1.2)	20 (1.1)	1 (6.3)
Sex, male	1156 (65.1)	1142 (64.9)	14 (87.5)	0.059
Smoking	887 (49.9)	873 (49.6)	14 (87.5)	0.010
Alcohol	591 (33.4)	579 (33.0)	12 (75.0)	0.001
BMI1 (kg/m2)	23.4 (21.5-25.2)	23.4 (21.5-25.2)	22.4 (18.5-23.9)	0.015
< 18.5	71 (4.0)	67 (3.8)	4 (25.0)	< 0.001
18.5-24.99	1219 (68.8)	1208 (68.8)	11 (68.8)
≥ 25	482 (27.2)	481 (27.4)	1 (0.2)
Postoperative BMI2 (kg/m2)	21.3 (19.5-23.1)	21.3 (19.5-23.1)	18.8 (18.2-20.6)	0.001
Comorbidity
Diabetes mellitus	173 (9.7)	171 (9.7)	2 (12.5)	0.664
Other malignancy	36 (2.0)	36 (2.0)	0 (0.0)	1.000
Previous TB infection	200 (11.3)	191 (10.9)	9 (56.3)	< 0.001
Laboratory data
Hemoglobin (g/dL)	13.8 (12.6-14.8)	13.8 (12.6-14.8)	13.6 (12.4-14.6)	0.340
Albumin (g/dL)	4.6 (4.4-4.8)	4.6 (4.4-4.8)	4.6 (4.3-4.9)	0.195
Cholesterol (mg/dL)	182 (160-206)	182 (160-206)	177 (152-190)	0.120
ASA physical status				0.222
Class I	1241 (69.9)	1226 (69.7)	15 (93.8)
Class II	495 (27.9)	494 (28.1)	1 (6.3)
Class III	40 (2.2)	40 (2.2)	0
Surgery extent, total gastrectomy	359 (20.2)	351 (19.9)	8 (50.0)	0.007
Cancer stage				0.616
IA	1255 (70.6)	1245 (70.7)	10 (62.5)
IB	253 (14.2)	252 (14.3)	1 (6.3)
II	156 (8.8)	153 (8.7)	3 (18.8)
III	94 (5.3)	92 (5.2)	2 (12.5)
IV	5 (0.3)	5 (0.3)	0 (0)
Cancer cell type				0.762
Adenocarcinoma	1239 (69.7)	1227 (69.7)	12 (75.0)
Signet-ring cell	454 (25.6)	451 (25.6)	3 (18.7)
Others	72 (4.0)	71 (4.0)	1 (6.2)
Death	42 (2.4)	53 (3.0)	1 (6.3)	0.391

Data are presented as n (%) or median (interquartile range) unless otherwise indicated.

¹Measured BMI before gastrectomy;

²Measured BMI about 1 yr after gastrectomy; not measured in 233 (13%) patients. TB: Tuberculosis; BMI: Body mass index; CXR: Chest X-ray; ASA: American Society of Anesthesiologists.

Table 2 Clinical and demographic characteristics of 16 tuberculosis patients after gastrectomy

Case	Sex/age	Historyof TB	Previoushealed TBon CXR	Smokinghistory	BMI(kg/m2)	Gastrectomyextent	Cancerstage	From surgery to TB onset (mo)	Site ofTB infection	TB diagnosismethod	TB treatmentoutcome
1	M/83	+	-	±	25.3	Total	IA	62	Lung	Culture	Death1
2	M/59	-	+	+	18.2	Total	IA	34	Lung	Culture	Cure
3	M/42	+	-	+	21.8	Total	IA	52	Lung	Culture	Cure
4	F/40	-	-	-	17.6	Subtotal	IA	13	Lung	Pathology (TBLB)	ND2
5	M/54	-	-	±	21.1	Subtotal	IA	7	Neck LN	Pathology (LN)	ND2
6	M/79	-	+	±	18.3	Subtotal	IA	46	Lung	Culture	Cure
7	M/52	-	-	±	17.2	Subtotal	IIIB	3	Neck LN	Pathology (LN)	Cure
8	M/45	+	+	+	23.6	Total	IB	16	Lung	Culture	Cure
9	F/71	-	-	-	24.9	Subtotal	IIIB	42	Lung	Culture	Cure
10	M/54	+	+	±	19.0	Subtotal	II	4	Lung	Pathology (VATS)	Cure3
11	M/41	-	-	±	23.4	Subtotal	IA	13	Intestine	Pathology (colon)	Cure
12	M/54	-	+	±	23.5	Total	IA	18	Lung, pleura	Culture	Cure
13	M/47	-	-	+	23.0	Total	IB	39	Lung	Clinical	Cure
14	M/62	+	-	+	24.3	Subtotal	IA	10	Lung	Clinical	Cure
15	M/67	-	-	±	20.0	Total	IA	9	Lung	Culture	Cure
16	M/67	+	+	±	23.9	Total	IB	39	Lung	Clinical	Cure

¹Death due to lung cancer progression during TB treatment;

²Patients were referred to other hospitals during TB treatment;

³Lung lesion by TB was resected and TB medication was used for only 2 wk due to side effects, but the patient was considered to be cured clinically. TB: Tuberculosis; BMI: Body mass index; CXR: Chest X-ray; LN: Lymph node; TBLB: Transbronchial lung biopsy; VATS: Video-assisted thoracoscopic surgery ± former smoker.

Table 3 Sex-age standardized incidence ratios of tuberculosis in gastrectomy patients

Subgroup	Gastrectomy patients, n	Sum of observation(patient-years)	Observed TB, n	Expected TB, n	Standardized incidence ratio	95%CI
Sex
Male	1156	4628.0	14	4.69	2.99	1.63-5.011
Female	620	2524.5	2	1.81	1.11	0.12-4.01
Age
20-29	13	57.7	0	0.05	-	-
30-39	112	465.6	0	0.30	-	-
40-49	343	1465.1	5	0.90	5.54	1.79-12.931
50-59	490	2072.3	5	1.60	3.16	1.02-7.381
60-69	557	2234.5	3	2.60	1.18	0.24-3.43
≥ 70	261	857.3	3	1.90	1.62	0.33-4.74
Total	1776	7152.5	16	7.20	2.22	1.27-3.601

¹Significantly higher than expected at the 5% level. New TB case notification rates in 2008 were used for estimation of expected TB cases. TB: Tuberculosis.

Table 4 Multivariate analysis for risk factors of active tuberculosis after gastrectomy

Variable	Odds ratio	95%CI	P value
Sex, male	1.29	0.18-9.40	0.801
Low BMI	1.21	1.01-1.46	0.043
Smoking	1.93	0.79-4.75	0.149
Alcohol	1.22	0.55-2.75	0.622
Previous TB infection	7.10	2.47-20.36	< 0.001
Surgery extent, total gastrectomy	3.48	1.25-9.66	0.017

TB: Tuberculosis; BMI: Body mass index; CXR: Chest X-ray.