Predicting lymph node metastasis in colorectal cancer using case-level multiple instance learning

Table 1 Baseline characteristics of the colorectal cancer patients included in the combined training and validation datasets (n = 130)

Characteristic		Number	Col%	n (LNM)	Row%	OR (95%CI)	P value
Sex	Male	71	55%	32	45%	1.00 (reference)	N/A
	Female	59	45%	27	46%	1.25 (0.62-2.50)	0.530
Age, years	< 60	29	22%	19	66%	1.00 (reference)	N/A
	60-69	32	25%	14	44%	0.60 (0.21-1.68)	0.327
	70-79	52	40%	18	35%	0.23 (0.09-0.62)	0.003
	> 80	17	13%	8	47%	0.37 (0.11-1.26)	0.112
CRC location	Colon	74	57%	27	37%	1.00 (reference)	N/A
	Rectum	56	43%	32	37%	1.79 (0.89-3.61)	0.104
Sideness	Proximal	39	30%	16	41%	1.00 (reference)	N/A
	Distal	91	70%	43	47%	1.11 (0.52-2.36)	0.788
CEA (ng/mL)	< 5	101	78%	45	45%	1.00 (reference)	N/A
	> 5	29	22%	14	48%	1.16 (0.51-2.66)	0.723
T stage	T3	95	73%	42	44%	1.00 (reference)	N/A
	T4	35	27%	17	49%	1.19 (0.55-2.59)	0.658

Col% represents the percentage distribution within the total cohort. n is the count of patients with lymph node metastasis (LNM) in each subgroup. Row% indicates the prevalence of LNM within each subgroup. Odds ratios (OR) and 95%CI reflect the association between each characteristic and LNM status, relative to the reference category. P-values assess the statistical significance of the ORs. CRC: Colorectal cancer; LNM: Lymph node metastasis; OR: Odds ratio; CEA: Carcinoembryonic antigen; N/A: Not applicable.