Patient Characteristics
A total of 646 patients with advanced stage III-IV gastric cancer who received Curative Gastrectomy during Perioperative Period were enrolled in this study, and the clinicopathological characteristics of the patients are shown in Table 1. Laparotomy was performed in 295 (45.7%) patients while the others received laparoscopic operation. Briefly, the patients age ranged from 23-89 years. Among all patients, there were 170 (26.3 %) females and 476 (73.7 %) males. 366(56.7%) patients with tumor size larger than 5cm. Of all 646 patients stage III 461(71.4%) and stage IV 185(28.6%), 112(17.3) patients without lymph node metastasis, 48(7.4%) patients with 1-2 lymph node metastases, 133(20.6%) patients with 3-6 lymph node metastases and 353(54.6%) patients with more than 6. 183(28.3%) patients had distant metastases.(Table 1)
Table 1. Clinicopathological characteristics of advanced GC patients
Characteristics
|
|
%
|
n=646
|
Gender
|
|
|
Male
|
476
|
73.7
|
Female
|
170
|
26.3
|
Age, y
|
|
|
23-60
|
248
|
38.4
|
61-89
|
398
|
61.6
|
Size
|
|
|
≤5
|
280
|
43.3
|
>5
|
366
|
56.7
|
TNM
|
|
|
3
|
461
|
71.4
|
4
N
0
1
2
3
|
185
112
48
133
353
|
28.6
17.3
7.4
20.6
54.6
|
M
|
|
|
0
|
463
|
71.7
|
1
|
183
|
28.3
|
Location
|
|
|
body of stomach
|
184
|
28.5
|
antrum of stomach
fundus of stomach
|
402
60
|
62.2
9.3
|
Surgical Approach
|
|
|
laparotomy
|
295
|
45.7
|
laparoscopic
|
351
|
54.3
|
Comparison of prognosis between PIV and its components and other IIBs
Of all components including LYM(AUC=0.423) MON(AUC=0.632) PLT(AUC=0.636) and NEU(AUC=0.669), PIV(AUC=0.725) shows a better prognostic value (Fig 1a).
When compared with other IIBs (SII NLR PLR and MLR), PIV has the largest AUC (0.725), which shows advantage in predictive value over SII(AUC=0.714) NLR(AUC=0.672) PLR(AUC=0.664) and MLR(AUC=0.670) (Fig 1b).
Correlation between PIV and clinicopathological characteristics of advanced gastric cancer patients
There were statistically significant differences in tumor size. While analysis of our data shows that gender, age, location and TNM stage correlate little with PIV (p>0.05, Table 2). Patients in the high PIV group were more likely to have larger tumor sizes than those in the low PIV group. (Table 2)
Table 2. Correlation between PIV and clinicopathological characteristics of advanced GC patients
Characteristics
|
Low PIV
(n = 303)
|
High PIV
(n = 343)
|
P-value
|
Gender
|
|
|
|
Male
|
229
|
247
|
0.304
|
Female
|
74
|
96
|
|
Age, y
|
|
|
|
≤ 60
|
117
|
131
|
0.912
|
> 60
|
186
|
212
|
|
Size
|
|
|
|
≤5
|
105
|
175
|
<0.005
|
>5
|
198
|
168
|
|
Location
|
|
|
|
body of stomach
|
85
|
99
|
0.912
|
antrum of stomach
fundus of stomach
|
191
27
|
211
33
|
|
TNM
|
|
|
|
3
|
212
|
249
|
0.461
|
4
|
91
|
94
|
|
M
|
|
|
|
0
|
213
|
250
|
0.466
|
1
|
90
|
93
|
|
N
|
|
|
|
0
|
53
|
59
|
0.158
|
1
|
23
|
25
|
|
2
|
66
|
67
|
|
3
X
|
123
38
|
166
26
|
|
Pearson’s correlation coefficient showed that PIV was positively correlated with CEA (r = 0.468, p < 0.05), and CA19-9 (r = 0.137, p < 0.05), negatively correlated with Alb (r = −0.126, p < 0.05). However, PIV was not correlated with CA125 or AFP (r = 0.120, and −0.140; p > 0.05) (Table 3). In addition, cases in the high PIV group were more likely to have low Alb level, larger tumor size compared with those in the low PIV group.
Table 3. Pearson’s correlation coefficient
Variables
|
median(range)
|
r
|
p-value
|
CEA
|
2.39(0.2-1000)
|
0.468
|
<0.05
|
CA19-9
CA125
AFP
Alb
|
12.46(0.6-1000)
15.31(1.87-1713)
2.32(0.5-1000)
36.5(14.4-51.6)
|
0.137
0.120
-0.140
-0.126
|
<0.05
0.188
0.775
<0.05
|
Kaplan-Meier curves of survival and subgroup analyses
The survival curves of GC are shown in Fig.2. The overall survival curve (38.9% vs. 78.4%, p < 0.01) was significantly worse in patients with high PIV than those in the low group. To better understand the effect of PIV prognosis between TNM3 and TNM4 stage, we performed subgroup analyses and confirmed the statistically significant differences between stage III(Fig.3a) and IV(Fig.3b) (TNM III: 48.6% vs. 92.4%, p<0.01; TNM IV: 32.8% vs. 78.4%, p<0.01).
As a result of univariate and multivariate analyses, PIV all appeared as an independent predictor in OS outcomes (Table 4). Besides, in multivariate analysis comprising the variables, tumor size and TNM stages caused a statistically significant difference in OS survival outcomes (Table 4). These results indicated that PIV was an independent value to predict survival in advanced GC patients.
Table 4. Univariate and Multivariate analysis of prognostic factors for overall survival in advanced GC patients
Covariate
|
Univariable
|
|
Multivariable
|
|
|
HR
(95%CI)
|
P-value
|
HR
(95%CI)
|
P-value
|
Age, y
Gender
Tumor size
TNM stage
Location
Surgical Approach
CEA
CA125
CA19-9
AFP
Alb
PIV
MLR
NLR
PLR
|
1.015
(0.791-1.302)
0.950
(0.721-1.252)
2.629
(1.990-3.472)
4.454
(3.482-5.697)
0.962
(0.783-1.182)
0.767
(0.600-0.979)
1.002
(1.001-1.003)
1.000
(0.999-1.001)
1.001
(1.001-1.002)
1.002
(1.000-1.003)
0.958
(0.937-0.978)
1.000
(1.000-1.001)
2.522
(2.147-2.962)
1.079
(1.065-1.093)
1.002
(1.001-1.003)
|
0.907
0.714
<0.001
<0.001
0.712
0.330
<0.001
0.971
<0.001
0.035
<0.001
<0.001
0.001
0.001
0.001
|
0.985
(0.502-1.933)
0.851
(0.402-1.801)
3.740
(1.725-8.108)
5.196
(2.538-10.638)
1.152
(0.703-1.888)
1.602
(0.769-3.338)
0.994
(0.989-0.998)
0.996
(0.992-1.001)
1.001
(1.000-1.003)
1.003
(1.000-1.005)
0.956
(0.894-1.022)
1.001
(1.000-1.001)
0.943
(0.348-2.557)
1.019
(0.925-1.122)
1.000
(0.997-1.003)
|
0.985
0.673
0.001
0.001
0.573
0.208
0.010
0.094
0.097
0.017
0.188
0.005
0.908
0.705
0.861
|