Table 1 Correlation between circCUL2 expression level and clinicopathologic characteristics of PDAC patients

Total cases

161

81

80

Gender

0.529

Male

87

46

41

Female

74

35

39

Age, mean ± SD, year ^b

60.10 ± 9.29

58.46 ± 7.96

0.232

Differentiation

0.061

Well

11

7

4

Moderate

88

50

38

Poor

62

24

38

TNM stage (AJCC) ^c

<0.001^***

I

31

25

6

II

103

50

53

III

27

6

21

Lymph-node metastasis

<0.001^***

Negative

61

48

13

Positive

100

33

67

Perineural invasion

0.641

Negative

21

12

9

Positive

140

69

71

Long-term smoking ^d

0.093

No

141

67

74

Yes

20

14

6

High-fat diet

0.269

No

138

72

66

Yes

23

9

14

Chronic pancreatitis

0.831

No

135

67

68

Yes

26

14

12

Abbreviations: SD = standard deviation; TNM = tumor node metastasis; AJCC = American Joint Committee on Cancer. ^a Chi-square test (except for age), ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001. ^b Unpair t test, ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001. ^c Patients were staged in accordance with the 8th Edition of the AJCC Cancer’s’ TNM Classification. ^d Long-term smoking (duration ≥ 29 years).