Table 1.

Characteristics of patients with IPMNs in the low-grade group and high-grade group

Characteristics	Training set (n = 103)			External Validation set 1 (n = 48)			External Validation set 2 (n = 51)
	Low grade (n = 77)	High grade (n = 26)	P-value	Low grade (n = 38)	High grade (n = 10)	P-value	Low grade (n = 37)	High grade (n = 14)	P-value
Gender			0.683			0.854			0.792
Male	53	19		23	7		27	9
Female	24	7		15	3		10	5
Age (year, range)	46 ~ 83	49 ~ 79	0.185	47–79	51–80	0.061	48–79	46–79	0.647
Symptom			0.122			0.336			0.107
Yes	31	15		14	6		12	8
No	46	11		24	4		25	6
Largest cyst size (cm)			0.042			0.044			0.020
> 3	27	15		11	7		13	10
≤ 3	50	11		27	3		24	4
Size of MPD (cm)			0.005			0.047			0.002
No dilatation	28	3		11	1		12	1
≤ 5	32	2		15	1		16	2
5 ~ 10	12	13		10	6		7	5
≥ 10	5	8		2	2		2	6
Enhancing mural nodule			0.027			0.017			0.014
Yes	18	12		9	7		10	9
No	59	14		29	3		27	5
Thickened and enhancing cyst walls			0.116			0.278			0.247
Yes	20	11		12	5		12	7
No	57	15		26	5		25	7
Abrupt change in caliber of pancreatic duct with distal pancreatic atrophy			0.694			0.569			0.644
Yes	15	6		6	3		9	5
No	62	20		32	7		28	9
CA19–9, kU/L			<  0.001			0.001			<  0.001
Normal	65	10		31	3		33	5
Elevated	12	16		7	7		4	9
CEA, ng/mL			0.978			0.215			0.714
Normal	62	21		32	6		30	10
Elevated	15	5		6	4		7	4
Indication for surgery			0.034			0.040			0.013
High risk factors	14	10		7	5		6	7
No high risk factors	63	16		31	5		31	7

MPD Main pancreatic duct, CA 19–9 Carbohydrate antigen, CEA Carcinoembryonic antigen