Predictive value of indirect bilirubin before neoadjuvant chemoradiotherapy in evaluating prognosis of local advanced rectal cancer patients

Table 3 Cox regression analysis of prognostic factors for disease-free survival

Characteristic	Univariable analysis		Multivariable analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Pre-IBIL
≤ 6.2 μmol/L	Reference		Reference
> 6.2 μmol/L	1.68 (1.12-2.53)	0.013	1.86 (1.22-2.84)	0.004
Age, yr
< 60	Reference
≥ 60	1.16 (0.78-1.74)	0.456
Sex
Female	Reference
Male	0.84 (0.55-1.28)	0.414
BMI, kg/m2
< 18.5	Reference		Reference
18.5-23.9	0.64 (0.26-1.61)	0.346	0.46 (0.18-1.17)	0.102
24.0-27.9	0.62 (0.24-1.57)	0.312	0.50 (0.19-1.30)	0.157
≥ 28.0	0.25 (0.07-0.87)	0.029	0.19 (0.05-0.66)	0.009
Smoking history
No	Reference
Yes	0.72 (0.48-1.08)	0.108
Drinking history
No	Reference
Yes	0.71 (0.47-1.07)	0.103
Chronic disease history
No	Reference
Yes	1.07 (0.72-1.61)	0.732
cTNM stage
II	Reference
III	1.49 (0.80-2.80)	0.210
nCRT with surgery interval, d
31-60	Reference		Reference
61-90	0.64 (0.41-0.99)	0.047	0.63 (0.40-0.99)	0.044
> 90	0.84 (0.40-1.77)	0.655	0.63 (0.29-1.35)	0.235
Inferior margin
≤ 5 cm	Reference
> 5 cm	0.80 (0.51-1.25)	0.318
TRG
1	Reference		Reference
2	0.45 (0.26-0.79)	0.006	0.43 (0.24-0.78)	0.005
3	0.29 (0.15-0.57)	< 0.001	0.30 (0.15-0.62)	0.001
4	0.31 (0.15-0.66)	0.002	0.31 (0.14-0.70)	0.005
Vascular invasion
Negative	Reference		Reference
Positive	2.54 (1.32-4.90)	0.005	2.24 (1.13-4.44)	0.021
Neural invasion
Negative	Reference		Reference
Positive	1.82 (1.17-2.82)	0.008	1.34 (0.82-2.18)	0.238
Radiotherapy type before surgery
VMAT	Reference
IMRT	1.07 (0.57-2.01)	0.836
3D-CRT	0.83 (0.20-3.37)	0.791
Chemotherapy type before surgery
Capecitabine	Reference
Capecitabine + platinum	0.98 (0.43-2.26)	0.969
Other	1.56 (0.72-3.37)	0.262
Adjuvant chemotherapy
No	Reference
Yes	0.89 (0.59-1.35)	0.584
Pre-CEA
≤ 5 ng/mL	Reference
> 5 ng/mL	1.33 (0.89-1.98)	0.158
Pre-CA19-9
≤ 27 U/mL	Reference
> 27 U/mL	1.47 (0.92-2.33)	0.104

HR: Hazard ratio; 95%CI: 95% confidence interval; nCRT: Neoadjuvant chemoradiotherapy; pre-IBIL: Indirect bilirubin before neoadjuvant chemoradiotherapy; BMI: Body mass index; TRG: Tumor regression grade; VMAT: Volumetric modulated arc therapy; IMRT: Intensity modulated radiation therapy; 3D-CRT: 3-dimensional conformal radiation therapy; pre-CEA: Carcinoembryonic antigen before neoadjuvant chemoradiotherapy; pre-CA19-9: Carbohydrate antigen 19-9 before neoadjuvant chemoradiotherapy.