Predictive value of serum calcium ion level in patients with colorectal cancer: A retrospective cohort study

Table 1 Baseline data of 280 patients with colorectal cancer, n (%)

Characteristics		Ca2+-first postoperative day		P value
		High group (> 1.975 mmol/L)	Low group (< 1.975 mmol/L)
n		179	101
Ethnic group				0.821
	Han ethnic group	149 (83.2)	83 (82.2)
	Others	30 (16.8)	18 (17.8)
Sex				0.693
	Female	77 (43.0)	41 (40.6)
	Male	102 (57.0)	60 (69.4)
Age (years)				0.012a
	< 65	121 (67.6)	53 (52.5)
	≥ 65	58 (32.4)	48 (47.5)
BMI				0.383
	< 23.5	65 (36.3)	42 (41.6)
	≥ 23.5	114 (63.7)	59 (58.4)
Tumor location				0.709
	Right half of colon	37 (22.6)	19 (15.1)
	Left half of colon	142 (77.4)	82 (84.9)
Degree of differentiation				0.018a
	High differentiation	24 (13.4)	3 (3.0)
	Moderately differentiated	127 (70.9)	80 (79.2)
	Poorly differentiated	28 (15.6)	18 (17.8)
T stage				0.313
	T1-2	39 (21.8)	21 (20.8)
	T3	106 (59.2)	53 (52.5)
	T4	34 (19.0)	27 (26.7)
N stage				0.907
	0	102 (54.7)	55 (52.3)
	N1	48 (45.3)	28 (47.7)
	N2	29 (16.2)	18 (17.8)
Neurovascular invasion				0.463
	No	133 (74.3)	79 (78.2)
	Yes	46 (25.7)	22 (21.8)
MSI				0.698
	MSS	164 (91.6)	94 (93.1)
	MSI-H	15 (8.4)	7 (6.9)
CEA (ug/L)				0.002a
	< 5	129 (72.1)	54 (53.5)
	≥ 5	50 (27.9)	47 (46.5)
CA19-9 (U/mL)				0.304
	< 39	158 (85.8)	90 (90.7)
	≥ 39	21 (14.2)	11 (9.3)
Hb (g/L)				0.753
	< 120	50 (27.9)	30 (29.7)
	≥ 120	129 (72.1)	71 (70.3)
PLT (109/L)				0.641
	< 330	143 (79.9)	83 (82.2)
	≥ 330	36 (20.1)	18 (17.8)
Alb (g/L)				0.175
	< 40	65 (36.3)	45 (44.6)
	≥ 40	114 (63.7)	56 (55.4)
Ca2+-baseline (mmol/L)				0.005a
	< 2.11	24 (7.5)	11 (9.3)
	≥ 2.11	155 (92.5)	90 (90.7)
δCa2+				< 0.001a
	< 0.245	145 (81.0)	28 (27.7)
	≥ 0.245	34 (19.0)	73 (72.3)

^aP < 0.05.

δCa²⁺: Delta serum calcium value; Alb: Albumin; BMI: Body mass index; CA19-9: Carbohydrate antigen 19-9; Ca²⁺-baseline: Baseline serum calcium ion levels; Ca²⁺-first postoperative day: Serum calcium ion level on the first day of postoperative period; CEA: Carcinoembryonic antigen; Hb: Hemoglobin; MSI: Microsatellite; PLT: Platelet.