World J Oncol

World Journal of Oncology, ISSN 1920-4531 print, 1920-454X online, Open Access

Article copyright, the authors; Journal compilation copyright, World J Oncol and Elmer Press Inc

Journal website https://wjon.elmerpub.com

Original Article

Volume 16, Number 3, June 2025, pages 269-275

Prognostic Significance of Post-Neoadjuvant Chemotherapy Carbohydrate Antigen 19-9 Levels in Patients With Resectable Pancreatic Cancer Treated With S-1 and Gemcitabine: A Retrospective Cohort Study

Figure 1. Kaplan-Meier curves stratified by CA19-9 levels (low vs. high). (a) Patients with low CA19-9 levels (< 100 U/mL) had significantly better disease-free survival (DFS) than those with high CA19-9 levels (median survival time (MST): low CA19-9, 24 months vs. high CA19-9, 7.0 months; P = 0.002). (b) Patients with low CA19-9 levels (< 100 U/mL) had significantly better overall survival (OS) than those with high CA19-9 levels (MST: low CA19-9, not reached vs. high CA19-9, 14.7 months; P = 0.001). CA19-9: carbohydrate antigen 19-9.

**Table 1.** Descriptive Statistics for the Total Cohort and Two Subgroups Stratified by Post-NATGS CA19-9 Levels
Statistics	Total cohort	Subgroup	P value
CA19-9: carbohydrate antigen 19-9; CEA: carcinoembryonic antigen; DUPAN-2: Duke pancreatic monoclonal antigen type 2; NAT: neoadjuvant therapy; GS: gemcitabine plus S-1. Location: Ph: pancreatic head; Pb: pancreatic body; Pt: pancreatic tail. RECIST: response evaluation criteria in solid tumor: CR: complete response; PR: partial response; SD: stable disease; PD: progressive disease. Operative procedures: PD: pancreaticoduodenectomy; TP: total pancreatectomy; DP: distal pancreatectomy. PV: portal vein.
Number	50	40	10
Sex, male/female	30:20	23:17	7:3	0.47
Age (years)	72 (50 - 86)	72 (56 - 86)	71 (50 - 80)	0.836
Pre-neoadjuvant CEA	2.5 (0.8 - 15.5)	2.5 (0.8 - 15.5)	2.5 (1.4 - 8.6)	0.402
Post-neoadjuvant CEA	2.55 (1 - 9.6)	2.45 (1 - 9.6)	2.7 (1.8 - 8.8)	0.308
Pre-neoadjuvant CA19-9	45.5 (5.3 - 1,379)	25 (5.8 - 232)	362 (74 - 1,379)	0.001
Post-neoadjuvant CA19-9	23.5 (2 - 1,436)	20.5 (2 - 99)	189.5 (102 - 1,436)	0.001
Pre-neoadjuvant DUPAN-2	65.5 (25 - 7,500)	42.5 (25 - 3,500)	145 (67 - 7,500)	0.006
Post-neoadjuvant DUPAN-2	37 (25 - 3,900)	26 (25 - 1,600)	140 (26 - 3,900)	0.002
Location Ph:Pb, Pt	28:22	17:23	5:5	0.731
Adverse event (hematological) ≥ grade 3	26 (52%)	21 (52.5%)	5 (50%)	0.582
Adverse event (non-hematological) ≥ grade 3	3 (6%)	2 (5%)	1 (10%)	0.4959
Completion of NAT (GS two cycles)	48 (96%)	39 (97.5%)	9 (90%)	0.363
RECIST CR:PR:SD:PD	0:5:45:0	0:4:36:0	0:1:9:0	0.347
Operative procedure (PD TP:DP)	28:22	16:24	4:6	0.302
PV resection	8	6	2	0.71
Operative time	404 (202 - 651)	400 (208 - 651)	420 (202 - 544)	0.942
Blood loss	526 (0 - 1651)	500 (0 - 1651)	794 (50 - 1396)	0.186
Tumor size	2.3 (0.3 - 6.0)	2.5 (0.3 - 3.7)	2.75 (1.5 - 4.5)	0.349
Nodal status (negative/positive)	34:26	30:10	4:6	0.056
Curative resection R0:R1:R2	43:7:0	35:5:0	8:2:0	0.541
Pathological response (Evans ≥ grade 3)	3 (6%)	3 (7.5%)	0	0.462
Complication (Clavien-Dindo 3a)	8 (16%)	6 (15%)	2 (20%)	0.768
Post-operative hospital stay	15 (9 - 46)	15 (9 - 46)	16.5 (9 - 35)	0.688
Adjuvant chemotherapy (completion)	39	30	9	0.305

Table 1. Descriptive Statistics for the Total Cohort and Two Subgroups Stratified by Post-NATGS CA19-9 Levels

Statistics

Total cohort

Subgroup

P value

CA19-9 < 100

CA19-9 ≥ 100

CA19-9: carbohydrate antigen 19-9; CEA: carcinoembryonic antigen; DUPAN-2: Duke pancreatic monoclonal antigen type 2; NAT: neoadjuvant therapy; GS: gemcitabine plus S-1. Location: Ph: pancreatic head; Pb: pancreatic body; Pt: pancreatic tail. RECIST: response evaluation criteria in solid tumor: CR: complete response; PR: partial response; SD: stable disease; PD: progressive disease. Operative procedures: PD: pancreaticoduodenectomy; TP: total pancreatectomy; DP: distal pancreatectomy. PV: portal vein.

Number

Sex, male/female

30:20

23:17

7:3

0.47

Age (years)

72 (50 - 86)

72 (56 - 86)

71 (50 - 80)

0.836

Pre-neoadjuvant CEA

2.5 (0.8 - 15.5)

2.5 (1.4 - 8.6)

0.402

Post-neoadjuvant CEA

2.55 (1 - 9.6)

2.45 (1 - 9.6)

2.7 (1.8 - 8.8)

0.308

Pre-neoadjuvant CA19-9

45.5 (5.3 - 1,379)

25 (5.8 - 232)

362 (74 - 1,379)

0.001

Post-neoadjuvant CA19-9

23.5 (2 - 1,436)

20.5 (2 - 99)

189.5 (102 - 1,436)

0.001

Pre-neoadjuvant DUPAN-2

65.5 (25 - 7,500)

42.5 (25 - 3,500)

145 (67 - 7,500)

0.006

Post-neoadjuvant DUPAN-2

37 (25 - 3,900)

26 (25 - 1,600)

140 (26 - 3,900)

0.002

Location Ph:Pb, Pt

28:22

17:23

5:5

0.731

Adverse event (hematological) ≥ grade 3

26 (52%)

21 (52.5%)

5 (50%)

0.582

Adverse event (non-hematological) ≥ grade 3

3 (6%)

2 (5%)

1 (10%)

0.4959

Completion of NAT (GS two cycles)

48 (96%)

39 (97.5%)

9 (90%)

0.363

RECIST CR:PR:SD:PD

0:5:45:0

0:4:36:0

0:1:9:0

0.347

Operative procedure (PD TP:DP)

28:22

16:24

4:6

0.302

PV resection

0.71

Operative time

404 (202 - 651)

400 (208 - 651)

420 (202 - 544)

0.942

Blood loss

526 (0 - 1651)

500 (0 - 1651)

794 (50 - 1396)

0.186

Tumor size

2.3 (0.3 - 6.0)

2.5 (0.3 - 3.7)

2.75 (1.5 - 4.5)

0.349

Nodal status (negative/positive)

34:26

30:10

4:6

0.056

Curative resection R0:R1:R2

43:7:0

35:5:0

8:2:0

0.541

Pathological response (Evans ≥ grade 3)

3 (6%)

3 (7.5%)

0.462

Complication (Clavien-Dindo 3a)

8 (16%)

6 (15%)

2 (20%)

0.768

Post-operative hospital stay

15 (9 - 46)

16.5 (9 - 35)

0.688

Adjuvant chemotherapy (completion)

0.305

**Table 2.** Univariate and Multivariate Analysis of Predictive Factors for Disease-Free Survival
	n	Univariate	Multivariate	Hazard ratio (95% CI)
Location: Ph: pancreatic head; Pb: pancreatic body; Pt: pancreatic tail. CA19-9: carbohydrate antigen 19-9; CEA: carcinoembryonic antigen; DUPAN-2: Duke pancreatic monoclonal antigen type 2; NAT: neoadjuvant therapy; CI: confidence interval.
Age < 72, ≥ 72	24:26	0.056
Sex, man/woman	30:20	0.471
Location Ph, Pb or Pt	22:28	0.14
Post-NAT, tumor size < 1.7, ≥ 1.7	30:20	0.039
Post-NAT, nodal status negative/positive	46:4	0.828
Pre-NAT, CEA < 5.0, ≥ 5.0	45:5	0.884
Pre-NAT, CA19-9 < 100, ≥ 100	38:12	0.007
Pre-NAT, DUPAN-2 < 150, ≥ 150	38:12	0.269
Post-NAT, CEA < 5.0, ≥ 5.0	42:8	0.727
Post-NAT, CA19-9 < 100, ≥ 100	40:10	< 0.001	< 0.001	11.72251 (2.798 - 49.099)
Post-NAT, DUPAN-2 < 150, ≥ 150	33:17	0.116

Table 2. Univariate and Multivariate Analysis of Predictive Factors for Disease-Free Survival

Univariate

Multivariate

Hazard ratio (95% CI)

Location: Ph: pancreatic head; Pb: pancreatic body; Pt: pancreatic tail. CA19-9: carbohydrate antigen 19-9; CEA: carcinoembryonic antigen; DUPAN-2: Duke pancreatic monoclonal antigen type 2; NAT: neoadjuvant therapy; CI: confidence interval.

Age < 72, ≥ 72

24:26

0.056

Sex, man/woman

30:20

0.471

Location Ph, Pb or Pt

22:28

0.14

Post-NAT, tumor size < 1.7, ≥ 1.7

30:20

0.039

Post-NAT, nodal status negative/positive

46:4

0.828

Pre-NAT, CEA < 5.0, ≥ 5.0

45:5

0.884

Pre-NAT, CA19-9 < 100, ≥ 100

38:12

0.007

Pre-NAT, DUPAN-2 < 150, ≥ 150

38:12

0.269

Post-NAT, CEA < 5.0, ≥ 5.0

42:8

0.727

Post-NAT, CA19-9 < 100, ≥ 100

40:10

< 0.001

11.72251 (2.798 - 49.099)

Post-NAT, DUPAN-2 < 150, ≥ 150

33:17

0.116

**Table 3.** Univariate and Multivariate Analysis of Predictive Factors for Overall Survival
	n	Univariate	Multivariate	Hazard ratio (95% CI)
Location: Ph: pancreatic head; Pb: pancreatic body; Pt: pancreatic tail. CA19-9: carbohydrate antigen 19-9; CEA: carcinoembryonic antigen; DUPAN-2: Duke pancreatic monoclonal antigen type 2; NAT: neoadjuvant therapy; CI: confidence interval.
Age < 72, ≥ 72	24:26	0.9258
Sex, man/woman	30:20	0.8242
Location Ph, Pb or Pt	22:28	0.849
Post-NAT, tumor size < 1.7, ≥ 1.7	30:20	0.2065
Post-NAT, nodal status negative/positive	46:4	0.5855
Pre-NAT, CEA < 5.0, ≥ 5.0	45:5	0.8884
Pre-NAT, CA19-9 < 100, ≥ 100	38:12	0.1329
Pre-NAT, DUPAN-2 < 150, ≥ 150	38:12	0.2541
Post-NAT, CEA < 5.0, ≥ 5.0	42:8	0.293
Post-NAT, CA19-9 < 100, ≥ 100	40:10	< 0.001	0.0025	17.88 (13.862 - 20,856.9)
Post-NAT, DUPAN-2 < 150, ≥ 150	33:17	0.0129	0.030	2.667 (1.5297 - 341.9195)

Table 3. Univariate and Multivariate Analysis of Predictive Factors for Overall Survival

Univariate

Multivariate

Hazard ratio (95% CI)

Age < 72, ≥ 72

24:26

0.9258

Sex, man/woman

30:20

0.8242

Location Ph, Pb or Pt

22:28

0.849

Post-NAT, tumor size < 1.7, ≥ 1.7

30:20

0.2065

Post-NAT, nodal status negative/positive

46:4

0.5855

Pre-NAT, CEA < 5.0, ≥ 5.0

45:5

0.8884

Pre-NAT, CA19-9 < 100, ≥ 100

38:12

0.1329

Pre-NAT, DUPAN-2 < 150, ≥ 150

38:12

0.2541

Post-NAT, CEA < 5.0, ≥ 5.0

42:8

0.293

Post-NAT, CA19-9 < 100, ≥ 100

40:10

< 0.001

0.0025

17.88 (13.862 - 20,856.9)

Post-NAT, DUPAN-2 < 150, ≥ 150

33:17

0.0129

0.030

2.667 (1.5297 - 341.9195)