Impact of sintilimab with first-line therapy on tumor marker response in advanced gastric cancer

Table 1 Comparison of tumor marker levels, mean ± SD

Group	Carcinoembryonic antigen (μg/mL)		CA19-9 (U/mL)			CA72-4 (U/mL)
	Pre-treatment	12 weeks	Pre-treatment	12 weeks	Pre-treatment	12 weeks
Control (n = 30)	8.85 ± 2.26	5.75 ± 1.70a	74.85 ± 12.26	38.25 ± 9.10a	12.68 ± 3.60	7.39 ± 1.65a
Combination (n = 30)	8.90 ± 2.28	4.27 ± 1.61a	69.80 ± 10.28	32.07 ± 10.61a	12.20 ± 3.57	6.24 ± 1.27a
t value	0.085	3.462	1.729	2.422	0.519	3.025
P value	0.932	0.001	0.089	0.019	0.606	0.004

^aP < 0.05 vs pre-treatment in the same group.

CA: Carbohydrate antigen.

Table 2 Comparison of tumor marker response rate, n (%)

Group	Tumor marker response rate (%)
	Carcinoembryonic antigen	CA19-9	CA72-4
Control (n = 30)	11 (36.67)	11 (36.67)	8 (26.67)
Combination (n = 30)	19 (63.33)	19 (63.33)	16 (53.33)
χ2 value	4.267	4.267	4.444
P value	0.039	0.039	0.035

CA: Carbohydrate antigen.

Table 3 Comparison of therapeutic efficacy, n (%)

Group	Complete response	Partial response	Stable disease	Progressive disease	Objective response rate	Disease control rate
Control (n = 30)	0 (0.00)	4 (13.33)	10 (33.33)	16 (53.33)	4 (13.33)	14 (46.67)
Combination (n = 30)	0 (0.00)	12 (40.00)	13 (43.33)	9 (30.00)	12 (40.00)	25 (83.33)
χ2 value	-				5.455	8.865
P value	-				0.020	0.003

Table 4 Comparison of tumor reduction rate, mean (interquartile range)

Group	Tumor reduction rate
	Pre-treatment (V0) (mm³)	Post-12-week (V1) (mm³)	Tumor reduction rate (ΔV%)
Control (n = 30)	41032 (12342, 134726)	33216 (6759, 73546)	19 (5, 32)
Combination (n = 30)	40321 (13452, 123492)	13246 (4358, 43667)	67 (52, 78)
Z value	0.125	2.894	5.672
P value	0.901	0.004	< 0.001

Table 5 Relationship between the maximum percentage reduction in tumor markers and the tumor reduction rate after treatment completion

Parameter	Tumor reduction rate (%)
	r value	P value
Δ Carcinoembryonic antigen %	0.642	0.004
ΔCA19-9%	0.587	0.025
ΔCA72-4%	0.613	0.003

CA: Carbohydrate antigen.