Chemotherapy plus bevacizumab with or without anti-programmed death 1 immunotherapy as the second-line therapy in colorectal cancer

Table 1 Baseline characteristics and treatment details of patients in the matched cohort, n (%)

Characteristics	Levels	Control group (n = 77)	Experiment group (n = 26)	P value
Age	> 60	33 (42.9)	12 (46.2)	0.949
	≤ 60	44 (57.1)	14 (53.8)
Gender	Male	55 (71.4)	18 (69.2)	1.000
	Female	22 (28.6)	8 (30.8)
ECOG	0-1	69 (89.6)	22 (84.6)	0.739
	2	8 (10.4)	4 (15.4)
Primary tumor location	Right colon	20 (26)	9 (34.6)	0.552
	Left colon and rectum	57 (74)	17 (65.4)
Primary tumor surgery	No	15 (19.5)	3 (11.5)	0.533
	Yes	62 (80.5)	23 (88.5)
Number of metastatic organs	1	26 (33.8)	8 (30.8)	0.968
	≥ 2	51 (66.2)	18 (69.2)
Liver metastasis	No	19 (24.7)	8 (30.8)	0.724
	Yes	58 (75.3)	18 (69.2)
Lung metastasis	No	41 (53.2)	11 (42.3)	0.461
	Yes	36 (46.8)	15 (57.7)
RAS mutation type	Unknown	15 (19.5)	5 (19.2)	0.872
	Wild-type	12 (15.6)	3 (11.5)
	Mutation	50 (64.9)	18 (69.2)

The control group received chemotherapy combined with bevacizumab; the experimental group received chemotherapy combined with bevacizumab and anti- programmed death 1 immunotherapy. ECOG: Eastern Cooperative Oncology Group.