Table 1 Baseline clinicopathological characteristics based on Adjuvant chemotherapy, before and after propensity score matching

Gender

 Male

24

70

24

27

 Female

25

49

24

21

Age(years)

 <  = 55

13

41

12

17

 > 55

36

78

36

31

Pathological diagnosis

 Ductal adenocarcinoma

30

93

29

34

 Acinar cell carcinoma

5

7

5

2

 Other

14

19

14

12

Tumor differentiation

 Low

14

56

13

22

 Moderate

28

49

28

21

 High

7

14

7

5

Tumor size(cm)

  <  = 5 cm

29

81

29

34

  > 5 cm

19

38

19

14

Microvascular invasion

 Absence

32

85

32

33

 Presence

17

34

16

15

Nerve invasion

 Absence

18

22

18

6

 Presence

31

97

30

42

Preoperative Ca19-9(u/ml)

  ≤ 37.00

18

32

18

11

  > 37.00

31

87

30

37

Preoperative CEA(ng/mL)

  ≤ 5.00

39

65

38

23

  > 5.00

10

54

10

25

Preoperative TBIL(umol/L)

  ≤ 17.10

35

96

35

37

  > 17.10

14

23

13

11

Tumor location

 Head and neck of pancreas

12

26

11

6

 Body and tail of pancreas

37

93

37

42

AJCC 8th Stage

 I

21

18

21

14

 II

15

73

14

24

 III

13

28

13

10

Lymphatic metastasis

 Absence

37

68

36

25

 Presence

12

51

12

23

Surgical type

 Open surgery

33

78

32

28

 Laparoscopic surgery

7

25

7

13

 Da Vinci Surgical System

9

16

9

7

Revascularization

 Absence

37

104

36

42

 Presence

12

15

12

6

Operation time (min)

  ≤ 180

12

17

12

7

  > 180

37

102

36

41

Amount of bleeding(mL)

  ≤ 400

33

82

33

32

  > 400

16

37

15

16

Perioperative blood transfusion

 Absence

29

88

29

32

 Presence

20

31

19

16

Surgical margin

 R0

42

95

41

41

 R1/R2

7

24

7

7

Postoperative pancreatic fistula

 Absence

37

88

36

34

 Presence

12

31

12

14

Postoperative hospitalization time(days)

  ≤ 14

39

83

38

33

  > 14

10

36

10

15