Evaluation of efficacy and safety of targeted therapy and immune checkpoint inhibitors in metastatic colorectal cancer

Table 1 Comparison of covariate balance in the study population before and after propensity score matching and inverse probability of treatment weighting analysis, n (%)

Variables	Original				1:1 PSM				IPW
	TT, n = 68	TT + ICI, n = 31	P value	SMD	TT, n = 24	TT + ICI, n = 24	P value	SMD	TT, n = 981	TT + ICI, n = 731	P value	SMD
Age			0.95	0.09			0.24	0.23			0.95	0.04
mean ± SD	61.8 ± 9.3	61.0 ± 9.6			62.0 ± 10.4	63.9 ± 7.86			61.9 ± 9.0	61.5 ± 9.3
Median (range)	62 (40-90)	64 (42-74)			62 (57-65)	65 (60-70)			63 (56-68)	64 (57-69)
Age groups (year)			0.86	0.09			0.36	0.39			0.86	0.03
> 60	41 (60.3)	20 (64.5)			14 (58.3)	18 (75.0)			62 (63.3)	47 (64.4)
≤ 60	27 (39.7)	11 (35.5)			10 (41.7)	6 (25.0)			36 (36.7)	26 (35.6)
Gender			0.47	0.21			1	0.09			0.47	0.05
Male	37 (54.4)	20 (64.5)			15 (62.5)	14 (58.7)			55 (56.1)	42 (58.3)
Female	31 (45.6)	11 (35.5)			9 (37.5)	10 (41.7)			43 (43.9)	30 (41.7)
Primary site			1	0.03			0.77	0.17			1	0.01
Rectal cancer	34 (50.5)	16 (51.6)			15 (62.5)	13 (54.2)			50 (51.0)	37 (50.7)
Colon cancer	34 (50.0)	15 (48.4)			9 (37.5)	11 (45.8)			48 (49.0)	36 (49.3)
Radical surgery			0.40	0.22			1	0.09			0.4	0.09
Yes	55 (80.9)	22 (71.0)			18 (73.1)	17 (70.8)			77 (77.8)	54 (74.0)
No	13 (19.1)	9 (29.0)			6 (26.9)	7 (29.2)			22 (22.2)	19 (26.0)
Treatment line			0.76	0.14			1	0.00			0.76	0.03
Third-line	56 (82.4)	27 (87.1)			21 (87.5)	21 (87.5)			82 (83.7)	62 (84.9)
Fourth-line	12 (17.6)	4 (12.9)			3 (12.5)	3 (12.5)			16 (16.3)	11 (15.1)
Targeted agents			0.87	0.03			1	0.00			1	0.06
Fruquintinib	60 (88.2)	27 (87.1)			22 (91.7)	22 (91.7)			86 (87.8)	65 (89.0)
Regorafenib	8 (11.8)	4 (12.9)			2 (8.3)	2 (8.3)			12 (12.2)	8 (11.0)
Treating hospital			0.27	0.35			1	0.00			0.27	0.09
NCUST-AH	9 (13.2)	4 (12.9)			3 (12.5)	3 (12.5)			13 (13.3)	10 (13.9)
TSPH	33 (48.5)	10 (32.3)			7 (29.2)	7 (29.2)			42 (42.9)	27 (37.5)
QPH	26 (38.2)	17 (54.8)			14 (58.3)	14 (58.3)			43 (43.9)	35 (48.6)
Metastatic status			0.51	0.54			0.97	0.30			0.53	0.30
LM	10 (14.7)	5 (16.1)			6 (25.0)	8 (33.3)			5 (15.3)	13 (18.1)
LuM	26 (8.3)	8 (25.8)			2 (8.3)	3 (12.5)			13 (33.7)	20 (27.8)
PM	3 (4.4)	2 (6.5)			2 (8.3)	2 (8.3)			5 (5.1)	4 (5.6)
LM + LuM	13 (19.1)	5 (16.1)			6 (25.0)	5 (20.8)			19 (19.4)	14 (19.4)
LuM + PM	2 (2.9)	1 (3.2)			1 (4.2)	1 (4.2)			3 (3.1)	3 (4.2)
LM + PM	3 (4.4)	0 (0)			0 (0)	0 (0)			3 (3.1)	0 (0)
OM	11 (16.2)	10 (32.2)			7 (29.2)	5 (20.8)			20 (20.4)	18 (25.0)
CEA level (ng/mL)			0.01	1.48			1	0.10			0.01	0.51
≤ 5	13 (19.1)	11 (35.5)			6 (25.0)	5 (20.8)			16 (16.3)	15 (20.8)
5 < CEA ≤ 25	21 (30.9)	3 (9.7)			1 (4.2)	1 (4.2)			21 (21.4)	3 (4.2)
> 25	34 (50.0)	17 (54.8)			17 (70.8)	18 (75.0)			61 (62.2)	54 (75.0)

¹The sample size indicated here represents the "pseudo-sample size" generated by applying the inverse probability of treatment weighting to the total population.

PSM: Propensity score matching; IPW: Inverse probability weighting; TT: Targeted therapy; ICI: Immune checkpoint inhibitor; NCUST-AH: North China University of Science and Technology Affiliated Hospital; TSPH: Tangshan People’s Hospital; QPH: Qinhuangdao People’s Hospital; LM: Liver metastasis; LuM: Lung metastasis; PM: Peritoneal metastasis; OM: Other metastases; CEA: Carcinoembryonic antigen.