ABO blood type, long-standing diabetes, and the risk of pancreatic cancer

Table 1 Characteristics of the diabetes mellitus group and the non-diabetes mellitus group n (%)

Variables	DM group (n = 114)	Non-DM group (n = 903)	P value	OR (95%CI)
Sex			0.002
Female	33 (28.9)	398 (44.1)		Reference
Male	81 (71.1)	505 (55.9)		3.17 (1.67-6.06)
Age (yr)			0.009
< 70	53 (46.5)	541 (59.9)		Reference
≥ 70	61 (53.5)	362 (40.1)		2.19 (1.20-3.98)
Smoking status	n = 991	n = 715	0.28
Former and current smokers	60 (60.6)	392 (54.8)
Non-smokers	39 (39.4)	323 (45.2)
Tumor location			0.37
Head	58 (50.9)	501 (55.5)
Body/tail	56 (49.1)	402 (44.5)
Family history of DM	n = 76	n = 393	< 0.001
No	41 (53.9)	335 (85.2)		Reference
Yes	35 (46.1)	58 (14.8)		6.21 (3.38-11.36)
ABO blood type	n = 104	n = 779	0.06
A	35 (33.7)	338 (43.4)		Reference
B	28 (26.9)	175 (22.5)		2.61 (1.24-5.47)
O	34 (32.7)	183 (23.5)		1.92 (0.95-3.87)
AB	7 (6.7)	83 (10.7)		0.94 (0.28-3.14)

¹Because of missing data, the numbers of subjects are presented for smoking status, family history of diabetes, and ABO blood type in each group. Diabetes mellitus (DM) group represents pancreatic cancer patients with long-standing type 2 diabetes, defined as diabetes lasting at 3 years prior to the diagnosis of pancreas cancer. Non-DM group represents pancreatic cancer patients without long-standing type 2 diabetes. OR: Odds ratio determined by the logistic regression method.

Table 2 Comparison of characteristics among 3 diabetes mellitus subgroups according to duration of diabetes

Variables	DM-S (n = 31)	DM-M (n = 48)	DM-L (n = 35)	P value
Sex ratio (M/F)	2.44	2.69	2.18	0.91
Age, yr (mean ± SD)	64.8 ± 9.2	67.1 ± 9.8	71.7 ± 7.0	0.007
≥ 70	41.9%	47.9%	71.4%	0.03
Smoking status	n = 261	n = 43	n = 30	0.12
Former and current smokers	50.0%	72.1%	53.3%
Tumor location: Head	54.8%	47.9%	51.4%	0.83
Family history of DM	n = 16	n = 36	n = 24	0.64
Positive family history of DM	56.3%	44.4%	41.7%
ABO blood type	n = 26	n = 44	n = 34	0.03
A	19.2%	52.3%	20.6%
B	26.9%	18.2%	38.2%
O	42.3%	27.3%	32.4%
AB	11.5%	2.3%	8.8%

¹Because of missing data, the numbers of subjects are presented for smoking status, family history of diabetes and ABO blood type in each group. F: Female; M: Male; DM: Diabetes mellitus; DM-S: Patients with diabetes of 3-5 years; DM-M: Patients with diabetes of 5.1-14.9 years; DM-L: Patients with diabetes of 15 years or more.

Table 3 Comparison of the distribution of ABO blood type between our cases and the general Japanese population n (%)

ABO blood type	Our pancreatic cancer patients (n = 883)	General Japanese population (n = 4465349)1
A	373 (42.2)	1725950 (38.7)
B	203 (23.0)	988996 (22.2)
O	217 (24.6)	1305924 (29.3)
AB	90 (10.2)	444479 (10.0)

¹The data was referred to Fujitas’ article[17].