Effectiveness and safety of chemotherapy for patients with malignant gastrointestinal obstruction: A Japanese population-based cohort study

Table 1 Patient characteristics

Variable	Chemotherapy (n = 470), n (%)	BSC (n = 652), n (%)	P value
Age
Young (age < 75 yr)	375 (79.8)	335 (51.4)	< 0.001
Elder (age ≥ 75 yr)	95 (20.2)	317 (48.6)
Sex
Male	284 (60.4)	363 (55.7)	0.112
Female	186 (39.6)	289 (44.3)
Charlson co-morbidity index score
< 3	175 (37.2)	343 (52.6)	< 0.001
≥ 3	295 (62.8)	309 (47.4)
Barthel index
≥ 60	422 (89.8)	436 (66.9)	< 0.001
< 60	27 (5.7)	153 (23.5)
Missing	21 (4.5)	63 (9.7)
Medication
Aspirin	18 (3.8)	33 (5.1)	0.329
Thienopyridine	7 (1.5)	24 (3.7)	0.027
Warfarin	8 (1.7)	20 (3.1)	0.148
DOACs	34 (7.2)	29 (4.4)	0.045
Other antiplatelet drugs	7 (1.5)	33 (5.1)	0.001
NSAIDs	293 (62.3)	314 (48.2)	< 0.001
Steroids	201 (42.8)	154 (23.6)	< 0.001
Cancer type
Esophageal cancer	24 (5.1)	83 (12.7)	< 0.001
Gastric cancer	151 (32.1)	113 (17.3)
Pancreatic cancer	69 (14.7)	106 (16.3)
Colorectal cancer	146 (31.1)	212 (32.5)
Other cancers	80 (17.0)	138 (21.2)
Cancer stage
Stage I-III	81 (17.2)	157 (24.1)	0.022
Stage IV or recurrence	297 (63.2)	379 (58.1)
Missing	92 (19.6)	116 (17.8)
Obstruction site
Esophageal obstruction	38 (8.1)	105 (16.1)	< 0.001
Gastroduodenal obstruction	189 (40.2)	233 (35.7)
Lower gastrointestinal obstruction	243 (51.7)	314 (48.2)
Chemotherapy before the intervention	274 (58.3)	413 (63.3)	0.087
Intervention type
Palliative surgery	294 (62.6)	283 (43.4)	< 0.001
SEMS placement	176 (37.4)	369 (56.6)

BSC: Best supportive care; DOACs: Direct oral anticoagulants; NSAIDs: Non-steroidal anti-inflammatory drugs; SEMS: Self-expandable metal stent.

Table 2 Factors affecting for overall survival

Factor	Univariate analysis		Multivariate analysis
	Crude HR (95%CI)	P value	Adjusted HR (95%CI)	P value
BSC	1		1
Chemotherapy after the intervention	0.38 (0.31-0.48)	< 0.001	0.36 (0.28-0.46)	< 0.001
Age
Young (age < 75 yr)	1		1
Elder (age ≥ 75 yr)	1.39 (1.10-1.75)	0.005	1.17 (0.92-1.49)	0.208
Sex
Male	1		1
Female	1.05 (0.84-1.30)	0.673	1.03 (0.83-1.29)	0.782
Charlson co-morbidity index
< 3	1		1
≥ 3	1.59 (1.27-2.00)	< 0.001	1.56 (1.24-1.97)	< 0.001
Barthel index
≥ 60	1		1
< 60	2.16 (1.64-2.84)	< 0.001	2.04 (1.53-2.73)	< 0.001
Medication
Aspirin non-use	1		1
Aspirin use	1.01 (0.62-1.64)	0.980	0.81 (0.49-1.33)	0.399
Thienopyridine non-use	1		1
Thienopyridine use	1.32 (0.70-2.47)	0.391	1.07 (0.56-2.03)	0.843
Warfarin non-use	1		1
Warfarin use	0.93 (0.42-2.09)	0.863	0.90 (0.40-2.02)	0.791
DOACs non-use	1		1
DOACs use	1.31 (0.87-1.95)	0.193	1.27 (0.85-1.91)	0.250
Other antiplatelet drugs non-use	1		1
Other antiplatelet drugs use	1.06 (0.60-1.89)	0.837	1.04 (0.58-1.86)	0.904
NSAIDs non-use	1		1
NSAIDs use	0.99 (0.80-1.23)	0.948	1.05 (0.83-1.33)	0.674
Steroid non-use	1		1
Steroid use	1.26 (1.02-1.57)	0.035	1.15 (0.92-1.45)	0.210
Cancer type
Esophageal cancer	1		1
Gastric cancer	0.68 (0.47-0.99)	0.045	0.64 (0.43-0.96)	0.030
Pancreatic cancer	1.00 (0.67-1.48)	0.991	0.92 (0.61-1.39)	0.697
Colorectal cancer	0.40 (0.27-0.59)	< 0.001	0.47 (0.30-0.73)	< 0.001
Other cancers	0.77 (0.53-1.13)	0.186	0.78 (0.51-1.18)	0.242
Cancer stage
Stage I-III	1		1
Stage IV or recurrence	1.96 (1.43-2.70)	< 0.001	1.79 (1.28-2.50)	< 0.001
Obstruction site
Esophageal obstruction	1		1
Gastroduodenal obstruction	0.84 (0.61-1.15)	0.274	1.03 (0.58-1.82)	0.918
Lower gastrointestinal obstruction	0.48 (0.35-0.66)	< 0.001	0.78 (0.42-1.44)	0.426
Non-chemotherapy before the intervention	1		1
Chemotherapy before the intervention	2.08 (1.68-2.57)	< 0.001	1.66 (1.31-2.09)	< 0.001
Intervention type
Palliative surgery	1		1
SEMS placement	2.03 (1.63-2.51)	< 0.001	1.63 (1.27-2.09)	< 0.001

CI: Confidence interval; DOACs: Direct oral anticoagulants; HR: Hazard ratio; NSAIDs: Non-steroidal anti-inflammatory drugs; SEMS: Self-expandable metal stent.

Table 3 Factors affecting for patency

Factor	Univariate analysis		Multivariate analysis
	Crude HR (95%CI)	P value	Adjusted HR (95%CI)	P value
BSC	1		1
Chemotherapy after the intervention	0.50 (0.42-0.59)	< 0.001	0.49 (0.41-0.59)	< 0.001
Age
Young (< 75 yr)	1		1
Elder (≥ 75 yr)	1.10 (0.92-1.33)	0.302	0.96 (0.79-1.17)	0.701
Sex
Male	1		1
Female	1.01 (0.85-1.20)	0.879	1.00 (0.84-1.19)	0.991
Charlson co-morbidity index
< 3	1		1
≥ 3	1.44 (1.21-1.72)	< 0.001	1.41 (1.18-1.69)	< 0.001
Barthel index
≥ 60	1		1
< 60	1.57 (1.24-1.97)	< 0.001	1.55 (1.22-1.97)	< 0.001
Medication
Aspirin non-use	1		1
Aspirin use	1.00 (0.67-1.49)	0.992	0.82 (0.55-1.24)	0.350
Thienopyridine non-use	1		1
Thienopyridine use	0.89 (0.50-1.58)	0.700	0.77 (0.43-1.37)	0.367
Warfarin non-use	1		1
Warfarin use	0.97 (0.52-1.82)	0.935	0.89 (0.47-1.67)	0.707
DOACs non-use	1		1
DOACs use	1.22 (0.88-1.70)	0.224	1.28 (0.92-1.79)	0.137
Other antiplatelet drugs non-use	1		1
Other antiplatelet drugs use	1.05 (0.66-1.66)	0.833	1.05 (0.66-1.66)	0.851
NSAIDs non-use	1		1
NSAIDs use	0.92 (0.78-1.10)	0.367	1.05 (0.87-1.26)	0.603
Steroid non-use	1		1
Steroid use	1.19 (1.00-1.42)	0.046	1.05 (0.88-1.26)	0.603
Cancer type
Esophageal cancer	1		1
Gastric cancer	0.86 (0.64-1.16)	0.321	0.98 (0.71-1.34)	0.888
Pancreatic cancer	1.11 (0.80-1.52)	0.531	1.18 (0.85-1.64)	0.324
Colorectal cancer	0.42 (0.30-0.57)	< 0.001	0.67 (0.47-0.95)	0.024
Other cancers	0.75 (0.55-1.03)	0.073	0.97 (0.69-1.36)	0.858
Cancer stage
Stage I-III	1		1
Stage IV or recurrence	1.87 (1.46-2.39)	< 0.001	1.65 (1.28-2.14)	< 0.001
Obstruction site
Esophageal obstruction	1		1
Gastroduodenal obstruction	0.88 (0.68-1.13)	0.325	1.22 (0.80-1.88)	0.356
Lower gastrointestinal obstruction	0.51 (0.39-0.66)	< 0.001	1.30 (0.81-2.08)	0.269
Non-chemotherapy before the intervention	1		1
Chemotherapy before the intervention	2.11 (1.78-2.50)	< 0.001	1.64 (1.36-1.98)	< 0.001
Intervention type
Palliative surgery	1		1
SEMS placement	2.84 (2.38-3.39)	< 0.001	2.48 (2.03-3.03)	< 0.001

CI: Confidence interval; DOACs: Direct oral anticoagulants; HR: Hazard ratio; NSAIDs: Non-steroidal anti-inflammatory drugs; SEMS: Self-expandable metal stent.

Table 4 Subgroup analysis of the effect of chemotherapy after the intervention on overall survival and patency duration

Subgroups	Overall survival		Patency duration
	Adjusted HR (95%CI)	P value	Adjusted HR (95%CI)	P value
All patients	0.36 (0.28-0.46)	< 0.001	0.49 (0.41-0.59)	< 0.001
Age
Young (< 75 yr)	0.36 (0.27-0.48)	< 0.001	0.48 (0.39-0.60)	< 0.001
Elder (≥ 75 yr)	0.38 (0.24-0.61)	< 0.001	0.52 (0.35-0.76)	< 0.001
Charlson co-morbidity index
< 3	0.43 (0.27-0.68)	< 0.001	0.47 (0.33-0.67)	< 0.001
≥ 3	0.31 (0.23-0.41)	< 0.001	0.47 (0.37-0.59)	< 0.001
Barthel index
≥ 60	0.38 (0.29-0.50)	< 0.001	0.52 (0.42-0.64)	< 0.001
< 60	0.24 (0.11-0.54)	< 0.001	0.26 (0.13-0.51)	< 0.001
Cancer type
Esophageal cancer	0.45 (0.21-1.00)	0.049	0.80 (0.43-1.49)	0.479
Gastric cancer	0.38 (0.24-0.62)	< 0.001	0.62 (0.43-0.90)	0.012
Pancreatic cancer	0.14 (0.07-0.29)	< 0.001	0.28 (0.17-0.45)	< 0.001
Colorectal cancer	0.45 (0.25-0.78)	0.005	0.45 (0.29-0.70)	< 0.001
Obstruction site
Esophageal obstruction	0.46 (0.23-0.92)	0.028	0.80 (0.47-1.37)	0.425
Gastroduodenal obstruction	0.26 (0.18-0.39)	< 0.001	0.37 (0.28-0.50)	< 0.001
Lower gastrointestinal obstruction	0.44 (0.30-0.64)	< 0.001	0.51 (0.38-0.69)	< 0.001
Intervention type
Palliative surgery	0.34 (0.24-0.48)	< 0.001	0.39 (0.29-0.52)	< 0.001
SEMS placement	0.37 (0.26-0.52)	< 0.001	0.54 (0.42-0.70)	< 0.001

CI: Confidence interval; HR: Hazard ratio; SEMS: Self-expandable metal stent.

Table 5 Adverse events

	Chemotherapy (n = 470), n (%)	BSC (n = 652), n (%)	P value
Perforation	6 (1.3)	6 (0.9)	0.567
Gastrointestinal bleeding	7 (1.5)	3 (0.5)	0.105