Retrospective Cohort Study
Copyright ©The Author(s) 2019.
World J Gastroenterol. Dec 14, 2019; 25(46): 6752-6766
Published online Dec 14, 2019. doi: 10.3748/wjg.v25.i46.6752
Table 1 Characteristics of patients enrolled in this study, n (%)
CharacteristicSEER database
West China Hospital database
MPV- groupMPV+ groupP valueMPV- groupMPV+ groupP value
Sample size, n6825714579110
Sex0.041a0.353
Male3458 (50.7)333 (46.6)368 (63.6)75 (68.2)
Female3367 (49.3)381 (53.4)211 (36.4)35 (31.8)
Age at diagnosis (± SEM)66.4 (± 0.13)65.4 (± 0.38)0.019a58.4 (± 0.41)58.35 (± 0.88)0.998
Tumor diameter0.000a0.003a
≤ 2 cm1232 (18.1)62 (8.7)130 (22.5)12 (10.9)
> 2 cm but ≤ 4 cm4377 (64.1)482 (67.5)373 (64.4)73 (66.4)
> 4 cm1216 (17.8)170 (23.8)76 (13.1)25 (22.7)
Positive lymph nodes0.1610.001a
01900 (27.8)214 (30.0)345 (59.6)46 (41.8)
1-32893 (42.4)311 (43.6)195 (33.7)48 (43.6)
≥ 42032 (29.8)189 (26.5)39 (6.7)16 (14.5)
AJCC 8th stage0.000a0.000a
IA500 (7.3)22 (3.1)89 (15.4)4 (3.6)
IB1162 (17.0)19 (20.9)219 (37.8)31 (28.2)
IIA238 (3.5)43 (6.0)37 (6.4)11 (10.0)
IIB2893 (42.4)311 (43.6)195 (33.7)45 (43.6)
III2032 (29.8)189 (26.5)39 (6.7)16 (14.5)
Perineural invasionN/A0.016a
AbsentN/AN/A165 (28.3)19 (17.3)
PresentN/AN/A415 (71.7)91 (82.7)
Intravascular tumor emboliN/A0.971
AbsentN/AN/A494 (85.3)94 (85.5)
PresentN/AN/A85 (14.7)16 (14.5)
Grade10.6050.984
Well differentiated632 (9.3)59 (8.3)5 (0.9)1 (1.0)
Moderately differentiated3397 (49.8)314 (44.0)215 (38.1)37 (37.4)
Poorly/undifferentiated2489 (36.5)251 (35.1)344 (61.0)61 (61.6)
Unknown307 (4.5)90 (12.6)0 (0.0)0 (0.0)
Margin status2N/A0.000a
R0N/AN/A427 (73.7)61 (55.5)
R1N/AN/A152 (26.3)49 (44.5)
R2N/AN/A0 (0.0)0 (0.0)
Table 2 Univariate and multivariate analyses of the survival of patients with pancreatic ductal adenocarcinoma
UnivariateSEER database
West China Hospital database
Hazard ratio (95%CI)P valueHazard ratio (95%CI)P value
Sex
Male1.000Reference1.000Reference
Female0.931(0.879, 0.987)0.017a0.861(0.709, 1.046)0.132
Tumor diameter0.000a0.000a
≤ 2 cm (T1)1.000Reference1.000Reference
> 2 cm but ≤ 4 cm (T2)1.375(1.267, 1.492)0.000a1.466(1.145, 1.878)0.002a
> 4 cm (T3)1.796(1.629, 1.982)0.000a2.466(1.789, 3.397)0.000a
Positive lymph nodes0.000a0.000a
0 (N0)1.000Reference1.000Reference
1-3 (N1)1.527(1.419, 1.644)0.000a1.676(1.378, 2.039)0.000a
> 4 (N2)1.940(1.791, 2.100)0.000a2.466(1.774, 3.429)0.000a
MPV invasion1.170(1.059, 1.293)0.002a1.708(1.352, 2.159)0.000a
MultivariateSEER databaseWest China Hospital database
Hazard ratio (95%CI)PHazard ratio (95%CI)P
Sex
Male1.000Reference
Female0.937(0.887, 0.989)0.018a
Tumor diameter0.000a0.000a
T11.000Reference1.000Reference
T21.299(1.203, 1.404)0.000a1.361(1.060, 1.746)0.015a
T31.611(1.468, 1.768)0.000a2.079(1.500, 2.880)0.000a
Positive lymph nodes0.000a0.000a
N01.000Reference1.000Reference
N11.454(1.358, 1.557)0.000a1.573(1.290, 1.916)0.000a
N21.842(1.710, 1.984)0.000a2.127(1.523, 2.971)0.000a
MPV invasion1.178(1.071, 1.290)0.000a1.423(1.120, 1.807)0.004a
Table 3 Differences in survival functions between American Joint Committee on Cancer TNM stages in patients stratified according to whether there was mesenterico-portal vein invasion
SEER database
West China Hospital database
MPV- groupMPV+ groupMPV- groupMPV+ group
Stage IA
Median survival38 (± 3.6)19 (± 3.4)32 (± 5.3)21
1-yr survival rate84.7% (± 1.7%)85.7% (± 7.6%)84.2% (± 4.0%)100.0%
3-yr survival rate51.7% (± 2.5%)26.8% (± 10.9%)45.4% (± 6.6%)0.0% (±0.0%)
5-yr survival rate39.4% (± 2.7%)26.8% (± 10.9%)36.0% (± 7.1%)0.0% (± 0.0%)
Stage IB
Median survival27 (± 1.3)22 (± 2.3)24 (± 1.6)17 (± 2.3)
1-yr survival rate78.0% (± 1.3%)76.6% (± 3.7%)79.0% (± 2.9%)72.5% (± 8.3%)
3-yr survival rate40.1% (± 1.6%)34.1% (± 4.6%)27.9% (± 3.8%)8.55% (± 5.7%)
5-yr survival rate27.6% (± 1.6%)23.7% (± 4.4%)20.9% (± 4.0%)4.35% (± 4.2%)
Stage IIA
Median survival20 (± 1.1)19 (± 6.6)18 (± 3.7)15 (± 3.7)
1-yr survival rate69.8% (± 3.1%)71.6% (± 7.3%)59.3% (± 8.5%)55.6% (± 16.6%)
3-yr survival rate24.7% (± 3.1%)32.8% (± 8.5%)13.7% (± 8.4%)0.0% (± 0.0%)
5-yr survival rate13.4% (± 2.7%)18.4% (± 8.1%)6.95% (± 6.4%)0.0% (± 0.0%)
Stage IIB
Median survival20 (± 0.5)17 (± 1.1)18 (± 1.0)15 (± 4.8)
1-yr survival rate68.7% (± 0.9%)63.6% (± 2.8%)66.7% (± 3.5%)63.3% (± 7.1%)
3-yr survival rate26.3% (± 0.9%)15.3% (± 2.3%)14.1% (± 3.1%)7.95% (± 4.3%)
5-yr survival rate15.9% (± 0.8%)9.25% (± 2.1%)5.65% (± 2.9%)0.0% (± 0.0%)
Stage III
Median survival16 (± 0.4)13 (± 1.2)15 (± 2.8)15 (± 4.8)
1-yr survival rate60.0% (± 1.1%)53.1% (± 3.9%)53.3% (± 8.4%)53.9% (± 14.1%)
3-yr survival rate17.6% (± 1.0%)8.65% (± 2.6%)10.4% (± 6.1%)0.0% (± 0.0%)
5-yr survival rate8.15% (± 0.8%)6.55% (± 2.4%)0.0% (± 0.0%)0.0% (± 0.0%)
IA vs IB
Survival functionP = 0.000aP = 0.917P = 0.044aP = 0.382
1-yr survival rateP = 0.002aP = 0.282P = 0.293
3-yr survival rateP = 0.000aP = 0.537P = 0.022aP = 0.136
5-yr survival rateP = 0.000aP = 0.792P = 0.064P = 0.306
IB vs IIA
Survival functionP = 0.000aP = 0.486P = 0.003aP = 0.264
1-yr survival rateP = 0.015aP = 0.541P = 0.028aP = 0.363
3-yr survival rateP = 0.000aP = 0.893P = 0.124P = 0.136
5-yr survival rateP = 0.000aP = 0.565P = 0.064P = 0.306
IIA vs IIB
Survival functionP = 0.622P = 0.136P = 0.523P = 0.500
1-yr survival rateP = 0.733P = 0.306P = 0.421P = 0.670
3-yr survival rateP = 0.620P = 0.047aP = 0.964P = 0.066
5-yr survival rateP =0.375P = 0.272P = 0.853
IIB vs III
survival functionP = 0.000aP = 0.053P = 0.033aP = 0.418
1-yr survival rateP = 0.000aP = 0.029aP = 0.141P = 0.552
3-yr survival rateP = 0.000aP = 0.054P = 0.589P = 0.066
5-yr survival rateP = 0.000aP =0.397P = 0.053
Table 4 The 8th edition of the American Joint Committee on Cancer staging system and the modified staging scheme
AJCC staging of pancreatic cancer (8th edition)Stage
Primary tumor size and extension (T)
T1: Tumor ≤ 2 cm in the greatest dimension, without involvement of the CA, SMA, and CHA.IA: T1N0M0
IB: T2N0M0
T2: Tumor > 2 cm and ≤ 4 cm in the greatest dimension, without involvement of the CA, SMA, and CHA.IIA: T3N0M0
IIB: T1-3N1M0
T3: Tumor > 4 cm in the greatest dimension, without involvement of the CA, SMA, and CHA.III: (1) TxN2M0;
T4: Tumor involves the CA, SMA, or CHA, regardless of size.(2) T4NxM0
Regional lymph node (N)IV: TxNxM1
N0: No positive regional lymph node
N1: 1-3 positive regional lymph nodes
N2: 4 or more positive regional lymph nodes
Distant metastasis (M)
M0: No distant metastasis
M1: Distant metastasis
Modified staging of pancreatic cancer
Primary tumor size and extension (T)
T1: Tumor ≤ 2 cm in the greatest dimension, without involvement of the CA, SMA, CHA, and MPVIA: T1N0M0
IB: T2N0M0
T2: Tumor > 2 cm and ≤ 4 cm in the greatest dimension, without involvement of the CA, SMA, CHA, and MPVIIA: T1N1M0
IIB: T3N0M0;
T3: Tumor involves the MPV, or > 4 cm in the greatest dimension, without involvement of the CA, SMA, and CHAT2N1M0
III: (1) T3N1M0;
T4: Tumor involves the CA, SMA, or CHA, regardless of size(2) TxN2M0;
Regional lymph node (N)(3) T4NxM0
N0: No positive regional lymph nodeIV: TxNxM1
N1: 1-3 positive regional lymph nodes
N2: 4 or more positive regional lymph nodes
Distant metastasis (M)
M0: No distant metastasis
M1: Distant metastasis
Table 5 Verification of the modified staging system in predicting prognosis
StageSEER database
West China Hospital database
Median survival1-yr survival rate, % (±%)3-yr survival rate, % (±%)5-yr survival rate, % (±%)Median survival1-yr survival rate, % (±%)3-yr survival rate, % (±%)5-yr survival rate, % (±%)
Prognostic comparison of different 8th edition AJCC T classifications
AJCC T127 (± 1.1)78.7 (± 1.2)39.7 (± 1.5)27.0 (± 1.5)25 (± 2.2)82.6 (± 3.3)32.9 (± 4.8)24.4 (± 4.9)
AJCC T220 (± 0.3)68.9 (± 0.7)26.0 (± 0.7)16.1 (± 0.7)19 (± 0.9)72.0 (± 2.2)21.5 (± 2.4)11.4 (± 2.2)
AJCC T315 (± 0.5)61.7 (± 1.4)18.7 (± 1.2)9.9 (± 1.0)15 (± 1.6)53.5 (± 5.3)10.4 (± 4.1)3.1 (± 2.8)
T1 vs T2P = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.002aP = 0.008aP = 0.034aP = 0.016a
T2 vs T3P = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.001aP = 0.019aP = 0.020a
Prognostic comparison of different modified T classifications
Modified T128 (± 1.2)78.7 (± 1.2)41.1 (± 1.6)27.8 (± 1.6)26 (± 2.6)82.6 (± 3.4)35.7 (± 5.1)26.5 (± 5.2)
Modified T220 (± 0.4)69.2 (± 0.7)26.6 (± 0.8)16.4 (± 0.7)21 (± 1.1)72.8 (± 2.4)21.8 (± 2.8)13.8 (± 2.7)
Modified T316 (± 0.4)60.5 (± 1.2)19.1 (± 1.0)10.7 (± 0.9)15 (± 0.8)61.1 (± 3.7)7.7 (± 2.5)2.6 (± 1.6)
T1 vs T2P = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.004aP = 0.019aP = 0.017aP = 0.030a
T2 vs T3P = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.008aP = 0.000aP = 0.000a
Prognostic comparison of different 8th edition AJCC stages
AJCC IA38 (± 3.4)84.8 (± 1.6)50.7 (± 2.5)38.9 (± 2.6)30 (± 4.6)84.9 (± 3.9)43.9 (± 6.5)34.8 (± 7.0)
AJCC IB27 (± 1.1)77.8 (± 1.2)39.4 (± 1.5)27.2 (± 1.5)23 (± 1.8)78.2 (± 2.7)25.6 (± 3.6)18.3 (± 3.5)
AJCC IIA20 (± 1.0)70.0 (± 2.8)25.8 (± 2.9)14.1 (± 2.6)16 (± 2.0)58.4 (± 7.6)9.9 (± 6.3)5.0 (± 4.7)
AJCC IIB19 (± 0.4)68.2 (± 0.9)25.2 (± 0.9)15.3 (± 0.8)17 (± 0.9)66.1 (± 3.1)12.7 (± 2.6)4.5 (± 2.3)
AJCC III16 (± 0.4)59.4 (± 1.1)16.8 (± 0.9)7.9 (± 0.7)15 (± 2.7)53.3 (± 7.2)6.8 (± 4.3)0.0
IA vs IBP = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.014aP = 0.158P = 0.014aP = 0.035a
IB vs IIAP = 0.000aP = 0.010aP = 0.000aP = 0.000aP = 0.001aP = 0.014aP = 0.030aP =0.023a
IIA vs IIBP = 0.958P = 0.541P = 0.843P = 0.659P = 0.425P = 0.348P = 0.681P = 0.924
IIB vs IIIP = 0.000aP = 0.000aP = 0.000aP = 0.000aP = 0.018aP = 0.102P = 0.240P = 0.050
Prognostic comparison of different modified stages
Modified IA38 (± 3.6)84.7 (± 1.7)51.7 (± 2.5)39.4 (± 2.7)32 (± 5.3)84.2 (± 4.0)45.4 (± 6.6)36.0 (± 7.1)
Modified IB27 (± 1.3)80.7 (± 1.2)40.1 (± 1.6)27.6 (± 1.6)24 (± 1.6)79.0 (± 2.9)28.6 (± 4.0)20.9 (± 4.0)
Modified IIA25 (± 1.4)75.6 (± 2.0)36.3 (± 2.3)22.5 (± 2.2)21 (± 3.3)77.3 (± 7.1)22.1 (± 7.6)14.7 (± 6.6)
Modified IIB20 (± 0.5)69.7 (± 1.0)25.4 (± 1.0)15.7 (± 0.9)18 (± 1.1)67.1 (± 3.4)10.5 (± 2.8)4.1 (± 2.2)
Modified III16 (± 0.3)60.0 (± 0.9)17.4 (± 0.8)8.6 (± 0.7)15 (± 1.0)56.2 (± 4.5)7.8 (± 2.8)0.0 (± 0.0)
IA vs IBP = 0.000aP = 0.055P = 0.000aP = 0.000aP = 0.044aP = 0.293P = 0.029aP = 0.064
IB vs IIAP = 0.008aP = 0.029aP = 0.175P = 0.061P = 0.425P = 0.825P = 0.449P = 0.422
IIA vs IIBP = 0.000aP = 0.008aP = 0.000aP = 0.004aP = 0.043aP = 0.195P = 0.152P = 0.128
IIB vs IIIP = 0.000aP =0.000aP = 0.000aP = 0.000aP = 0.004aP = 0.053P = 0.495P = 0.062