Combining prognostic value of serum carbohydrate antigen 19-9 and tumor size reduction ratio in pancreatic ductal adenocarcinoma

Table 1 Characteristics of all pancreatic ductal adenocarcinoma patients

Variables	Total patients, n = 156	%
Age in yr	65.4 ± 10.6
Sex
Female	72	46.2
Male	84	53.8
ASA-score classification
2	58	37.2
3	60	62.8
BMI	23.3 ± 6.5
CR
< 0.5	45	28.8
≥ 0.5 or < 1	90	57.7
≥ 1	21	13.5
Charlson comorbidity Index
0	117	75
1	29	18.6
2	10	6.4
Tumor and pathologic characteristics
AJCC TNM stage
Ia	12	7.7
Ib	41	26.3
Iia	58	37.2
Iib	45	28.8
Grade
0	10	6.4
G1	35	22.4
G2	75	48.1
G3	36	23.1
Neoadjuvant Chx
Yes	128	82.1
No	28	17.9
Neoadjuvant Rtx
Yes	37	33.7
No	119	76.3
TR
< 0.5	4	2.6
≥ 0.5 or < 1	123	78.8
≥ 1	29	18.6
Neural invasion
Yes	65	41.7
No	91	58.3
Vascular invasion
Yes	76	48.7
No	80	51.3
Positive lymph nodes
0	50	32.1
1-2	37	33.7
> 2	69	44.2
Tumor resection
R0	65	41.7
R1	91	58.3
Operation type
Whipple	117	75.0
Distal pancreatectomy	30	19.2
Distal pancreatectomy with celiac axis resection	9	4.8

AJCC: American Joint Committee on Cancer; ASA: American Society of Anesthesiologists; BMI: Body mass index; Chx: Chemotherapy; CR: Carbohydrate antigen 19-9 ratio; Rtx: Radiotherapy; TR: Tumor size ratio.

Table 2 Cox proportional hazard regression analysis of patients' demographic and clinical characteristics related with overall survival

Variable	Univariate			Multivariate
	HR	95%CI	P value	HR	95%CI	P value
Age in yr, median range	1.043	0.795-1.149	0.857
Sex, male/female	0.948	0.743-1.219	0.395
ASA score classification, 0/1 or 2	1.103	0.854-1.754	0.194
BMI	0.931	0.803-1.140	0.454
TNM stage, I or II/III	1.436	1.217-2.695	0.015	1.526	1.226-4.165	0.007
Neoadjuvant Chx, yes/no	1.201	1.114-2.742	0.024
Neoadjuvant Rtx, yes/no	1.121	0.901-1.537	0.142
Neural invasion, yes/no	1.103	0.965-2.542	0.104
Vascular invasion, yes/no	1.439	1.294-3.594	0.003	1.653	1.253-3.651	0.021
Positive lymph nodes, yes/no	1.729	1.487-4.325	0.001
Tumor resection, R0/R1	0.568	0.321-0.843	0.005
Operation type, Whipple	1.104	0.549-2.130	0.392
CR, ≥ 1/< 1	1.796	1.429-4.104	0.001	1.721	1.373-3.762	0.006
TR, ≥ 1/< 1	1.573	1.282-2.752	0.012	1.435	1.275-4.363	0.014

BMI: Body mass index; Chx: Chemotherapy; CR: Carbohydrate antigen 19-9 ratio; Rtx: Radiotherapy; TR: Tumor size ratio.