Machine learning-based radiomics score improves prognostic prediction accuracy of stage II/III gastric cancer: A multi-cohort study

Table 1 Baseline data of the discovery and the Cancer Imaging Archive cohorts, n (%)

	Discovery cohort	TCIA cohort	P value
	(n = 141)	(n = 40)
Gender			0.002
Male	79 (56.0)	33 (82.5)
Female	62 (44.0)	7 (17.5)
Age (yr)	56.3 (12.1)	65.0 (9.6)	< 0.001
ASA			NA
1	70 (49.6)	Not reported
2	40 (28.4)
3	31 (22.0)
CEA (ng/mL)			NA
≤ 5	109 (77.3)	Not reported
> 5	32 (22.7)
Operation			< 0.001
Proximal	18 (12.8)	17 (42.5)
Distal	84 (59.6)	11 (27.5)
Total	39 (27.7)	12 (30.0)
Tumor size	4.3 (1.2)	Not reported	NA
Nerve or vascular invasion			NA
Yes	54 (38.3)	Not reported
No	87 (61.7)
SMI	46.8 (14.5)	44.8 (13.4)	0.009
SMD	33.2 (6.8)	34.6 (7.2)	0.032
Differentiation			NA
Good	13 (9.2)	Not reported
Moderate	63 (44.7)
Poor	65 (46.1)
T stage			0.097
2-3	66 (46.8)	23 (57.5)
4	75 (53.2)	17 (42.5)
N stage			< 0.001
0-1	33 (23.4)	16 (40.0)
> 1	108 (76.6)	24 (60.0)
TD			NA
Yes	29 (20.6)	Not reported
No	112 (79.4)
TNM stage
II	65 (46.1)	12 (30.0)	< 0.001
III	76 (53.9)	28 (70.0)
Chemotherapy			NA
Yes	90 (63.8)	Not reported
No	51 (36.2)

SMI: Skeletal muscle index; SMD: Skeletal muscle density; TD: Tumor deposition; NA: Not available; TCIA: The Cancer Imaging Archive; TNM: Tumor, node, and metastasis; ASA: American Association of Anesthesiologists score; CEA: Carcinoembryonic antigen.

Table 2 Univariate and multivariate Cox regression

	Univariate		Multivariate
	RR (95%CI)	P value	RR (95%CI)	P value
Gender (female)	0.885 (0.523-1.498)	0.649
Age (yr)	1.002 (0.981-1.024)	0.843
ASA
1	Ref
2	1.338 (0.669-2.675)	0.411
3	0.979 (0.496-1.934)	0.952
SMI	0.958 (0.930-0.986)	0.004	0.968 (0.932-0.991)	0.009
SMD	0.907 (0.872-0.943)	< 0.001	0.936 (0.889-0.975)	0.002
OACRS	3.158 (1.378-5.247)	< 0.001	3.023 (1.896-4.365)	< 0.001
Operation
Proximal	Ref
Distal	1.499 (0.632-3.553)	0.369
Total	1.018 (0.390-2.652)	0.972
CEA (< 5 ng/mL)	2.236 (1.275-3.921)	0.005	3.174 (1.635-6.035)	0.003
Tumor size	1.035 (0.917-1.168)	0.58
Nerve or vascular invasion	1.700 (1.006-2.871)	0.047
TD (No)	2.167 (1.233-3.810)	0.007
Differentiation
Good	Ref
Moderate	1.808 (0.814-4.016)	0.146
Poor	0.996 (0.569-1.744)	0.989
T stage (2/3)	1.472 (0.867-2.499)	0.153
N stage (0-1)	4.501 (1.793-11.299)	0.001
TNM stage (II)	6.325 (3.425-11.680)	< 0.001	3.698 (2.478-7.635)	< 0.001
Chemotherapy (No)	0.410 (0.241-0.697)	0.001	0.496 (0.268-0.768)	0.002

SMI: Skeletal muscle index; SMD: Skeletal muscle density; TD: Tumor deposition; NA: Not available; TNM: Tumor, node, and metastasis; ASA: American Association of Anesthesiologists score; CEA: Carcinoembryonic antigen; OACRS: Overall survival-associated computed tomography image radiomics score.