An interpretable machine learning model based on computed tomography radiomics for predicting programmed death ligand 1 expression status in gastric cancer

Table 1 Patient clinical characteristics in training, validation, and test sets

Characteristic	Training set (n = 143)	Validation set (n = 62)	Test set (n = 80)	P value
PD-L1 expression (No. %)				0.584
CPS < 5	73 (51.1%)	31 (50.0%)	46 (57.5%)
CPS ≥ 5	70 (49.0%)	31 (50.0%)	34 (42.5%)
*Age (years)**	59.0 (29–83)	59.0 (27–81)	57.0 (27–79)	0.563
Sex (No. %)				0.636
Male	50 (35.0%)	26 (41.9%)	30 (37.5%)
Female	93 (65.0%)	36 (58.1)	50 (62.5%)
CEA (No. %)				0.084
< 5.0 µg/ml	103 (72.0%)	40 (64.5%)	46 (57.5%)
≥ 5.0 µg/ml	40 (28.0%)	22 (35.5%)	34 (42.5%)
CA199 (No. %)				0.314
< 30 U/mL	108 (75.5%)	46 (74.2%)	53 (66.3%)
≥ 30 U/mL	35 (24.5%)	16 (25.8%)	27 (33.7%)
CA242 (No. %)				0.107
< 20 U/mL	116 (81.1%)	51 (82.3%)	56 (70.0%)
≥ 20 U/mL	27 (18.9%)	11 (17.7%)	24 (30.0%)
CA724 (No. %)				0.304
< 6.9 U/mL	101 (70.6%)	44 (71.0%)	49 (61.3%)
≥ 6.9 U/mL	42 (29.4%)	18 (29.0%)	31 (38.7%)
TNM stage (No. %)				0.488
I	14 (9.8%)	9 (14.5%)	11 (13.8%)
II	34 (23.8%)	19 (30.7%)	25 (31.3%)
III	86 (60.1)	29 (46.8%)	37 (46.2%)
IV	9 (6.3%)	5 (8.1%)	7 (8.7%)

Note: Presented as No. %, and compared using the chi-square or Fisher’s exact test. ^*Presented as median (range), and compared using the Mann–Whitney U test
Abbreviations: PD-L1, programmed death-ligand 1; CPS, combined positive score; CEA, carcinoma embryonic antigen; CA199, carbohydrate antigen 19 − 9; CA72, carbohydrate antigen 72 − 4; CA242, carbohydrate antigen 24 − 2; TNM, tumor node metastasis

ISSN: 1470-7330