Table 1 Univariable and multivariable analysis of factors associated with overall survival.

Sex

 Male

22.31 (19.22–27.63)

1

 Female

20.17 (17.77–24.64)

1.07 (0.86–1.32)

0.545

PS

 0

32.85 (17.77-53.09)

1

1

 1

24.49 (21.88–28.45)

1.18 (0.77–1.81)

1.05 (0.647–1.636)

0.83

 2

15.01 (11.97–25.56)

1.92 (1.2–3.09)

0.001

1.7 (1.029–2.804)

0.038

Tumour grade

 Mod

28.98 (24.47–33.02)

1

1

 Poor

16.1 (13.76–19.81)

1.72 (1.39–2.14)

0

1.36 (1.035–1.786)

0.028

T_stage

 ½

38.67 (32.23-81.9)

1

1

 ¾

19.09 (17.08-22.14)

2.04 (1.5–2.77)

0

2.03 (1.336–3.096)

0.001

N_stage

 Negative

42.25 (35.64-55.65)

1

1

 Positive

18.69 (16.379–21.75)

1.97 (1.49–2.6)

0

2.28 (1.576–3.285)

<0.001

R_margin

 Negative

37.91 (30.03–52.56)

1

1

 Positive

18.2 (16.43–21.94)

1.97 (1.52–2.55)

0

1.82 (1.279–2.603)

0.001

Perineural invasion

 No

38.67 (30.78-NA)

1

 Yes

19.69 (17.64–22.27)

2.26 (1.91–2.5)

0.001

Lymphovascular invasion

 No

24.16 (20.83–34.23)

1

 Yes

19.81 (17.71–24.01)

1.39 (1.08–1.8)

0.011

Adjuvant Chemo

 No

8.67 (6.01–13.14)

1

1

 Yes

25.25 (22.31–29.04)

0.4 (0.3–0.53)

0.31 (0.201–0.488)

<0.001

Chemo cycle no. + DR

 ≥6 cycles (full dose)

28.5 (24.47–33.54)

1

1

 ≥6 cycles (reduced dose)

27.5 (22.04–44.65)

0.88 (0.6–1.28)

1.14 (0.766–1.706)

0.513

 <6 cycles (full dose)

12.55 (11.99–31.96)

1.91 (1.18–3.1)

1.66 (1.006–2.744)

0.048

 <6 cycles (reduced dose)

11.97 (9.03–NA)

2.44 (1.3–4.57)

0

4.01 (2.006–7.79)

<0.001

Chemotherapy start

 ≤8 weeks

25.92 (20.73–33.54)

1

 >8 weeks

25.3 (22.27–29.7)

1.07 (0.78–1.45)

0.674

Pre chemo CA19-9

 Low

29.86 (26.38–33.34)

1

1

 High

10.96 (9.99–13.76)

3.8 (2.75–5.27)

0

1.39 (1.261–1.523)

<0.001

Chemo regimen

 None

9.71 (6.93–14.59)

1

 Gem

22.17 (18.79–25.3)

0.43 (0.31–0.62)

 GemCap

28.78 (24.28–33.74)

0.3 (0.21–0.43)

 mFOLFIRINOX

28.98 (15.18- NA)

0.28 (0.15-0.54)

 Other

25.92 (20.8–NA)

0.33 (0.17–0.65)

0