3.1 Patient baseline characteristics
Figure 1 illustrates the data filtering process. Following a rigorous application of inclusion and exclusion criteria, a cohort of 12,780 individuals diagnosed with rectal cancer was selected for the study. Through the utilization of R software, these patients were randomly split into a training cohort and a validation cohort in a 7:3 ratio, resulting in 8948 patients in the training cohort and 3832 patients in the validation cohort. The baseline characteristics of the patients in both cohorts were found to be similar, as showed by Table 1.
Table 1 Baseline characteristics of enrolled patients
Variables
|
Overall cohort
(n = 12780)
|
Training cohort
(n =8948)
|
Validation cohort
(n = 3832)
|
p value
|
Sex, n (%)
|
|
|
|
0.976
|
Male
|
7508(58.7)
|
5256(58.7)
|
2252(58.8)
|
|
Female
|
5272(41.3)
|
3692(41.3)
|
1580(41.2)
|
|
Age, Median (IQR)
|
74.0(69.0, 80.0)
|
74.0(69.0, 80.0)
|
74.0(69.0, 80.0)
|
0.907
|
Race, n (%)
|
|
|
|
0.429
|
White
|
10613(83.0)
|
7413(82.8)
|
3200(83.5)
|
|
Black
|
856( 6.7)
|
616(6.9)
|
240(6.3)
|
|
Other
|
1311(10.3)
|
919(10.3)
|
392(10.2)
|
|
Year of diagnos, n (%)
|
|
|
|
0.592
|
2010-2011
|
4376(34.2)
|
3089(34.5)
|
1287(33.6)
|
|
2012-2013
|
4433(34.7)
|
3089(34.5)
|
1344(35.1)
|
|
2014-2015
|
3971(31.1)
|
2770(31)
|
1201(31.3)
|
|
Marital status, n (%)
|
|
|
|
0.446
|
Single
|
1219( 9.5)
|
834(9.3)
|
385(10)
|
|
Married
|
7095(55.5)
|
4988(55.7)
|
2107(55)
|
|
Divorced
|
1154( 9.0)
|
795(8.9)
|
359(9.4)
|
|
Other
|
3312(25.9)
|
2331(26.1)
|
981(25.6)
|
|
Grade, n (%)
|
|
|
|
0.719
|
Ⅰ
|
1061( 8.3)
|
741(8.3)
|
320(8.4)
|
|
Ⅱ
|
9963(78.0)
|
6984(78.1)
|
2979(77.7)
|
|
Ⅲ
|
1591(12.4)
|
1102(12.3)
|
489(12.8)
|
|
Ⅳ
|
165( 1.3)
|
121(1.4)
|
44(1.1)
|
|
CEA, n (%)
|
|
|
|
0.448
|
Positive
|
4917(38.5)
|
3451(38.6)
|
1466(38.3)
|
|
Negative
|
7765(60.8)
|
5434(60.7)
|
2331(60.8)
|
|
Borderline
|
98( 0.8)
|
63(0.7)
|
35(0.9)
|
|
Tumor.size, n (%)
|
|
|
|
0.918
|
<3
|
3550(27.8)
|
2476(27.7)
|
1074(28)
|
|
3-5
|
4648(36.4)
|
3271(36.6)
|
1377(35.9)
|
|
5-7
|
2896(22.7)
|
2020(22.6)
|
876(22.9)
|
|
≥7
|
1686(13.2)
|
1181(13.2)
|
505(13.2)
|
|
T stage, n (%)
|
|
|
|
0.734
|
T1
|
1832(14.3)
|
1265(14.1)
|
567(14.8)
|
|
T2
|
2850(22.3)
|
2012(22.5)
|
838(21.9)
|
|
T3
|
7107(55.6)
|
4976(55.6)
|
2131(55.6)
|
|
T4
|
991( 7.8)
|
695(7.8)
|
296(7.7)
|
|
N stage, n (%)
|
|
|
|
0.684
|
N0
|
7988(62.5)
|
5582(62.4)
|
2406(62.8)
|
|
N1
|
3587(28.1)
|
2530(28.3)
|
1057(27.6)
|
|
N2
|
1205( 9.4)
|
836(9.3)
|
369(9.6)
|
|
TNM Stage, n (%)
|
|
|
|
0.851
|
Ⅰ
|
3866(30.3)
|
2694(30.1)
|
1172(30.6)
|
|
Ⅱ
|
4122(32.3)
|
2888(32.3)
|
1234(32.2)
|
|
Ⅲ
|
4792(37.5)
|
3366(37.6)
|
1426(37.2)
|
|
Months.from.diagnosis.to.treatment,Mean ± SD
|
1.2 ± 1.2
|
1.2 ± 1.2
|
1.1 ± 1.1
|
0.129
|
Surgery, n (%)
|
|
|
|
0.667
|
No
|
1242( 9.7)
|
863(9.6)
|
379(9.9)
|
|
Yes
|
11538(90.3)
|
8085(90.4)
|
3453(90.1)
|
|
Radiation, n (%)
|
|
|
|
0.491
|
No
|
5444(42.6)
|
3794(42.4)
|
1650(43.1)
|
|
Yes
|
7336(57.4)
|
5154(57.6)
|
2182(56.9)
|
|
Chemotherapy, n (%)
|
|
|
|
0.771
|
No
|
5288(41.4)
|
3695(41.3)
|
1593(41.6)
|
|
Yes
|
7492(58.6)
|
5253(58.7)
|
2239(58.4)
|
|
3.2 Univariate and Multivariate Analyses for OS and CSS of training cohort
To develop the prognostic model, we used Cox regression models to screen for prognostic factors affecting OS and CSS. First, all 13 original variables were included in the regression model (Table 2). Univariate Cox regression found that 10 variables were risk factors for CSS in the Training cohort: race, marital status, grade, T stage, N stage, TNM Stage, CEA, tumor size, surgery, radiation. In addition, sex, race, marital status, grade, T stage, N stage, TNM Stage, CEA, months from diagnosis to treatment, surgery, radiation and chemotherapy were risk factors for OS. Subsequently, variables with statistical significance (p<0.05) in univariate analysis were included in multivariate analysis (Table 3). Multivariate analysis results indicated that marital status, grade, T stage, N stage, TNM Stage, CEA, tumor size, surgery and radiation were the independent prognostic factors for CSS, whereas sex, race, marital status, grade, T stage, N stage, TNM Stage, CEA, tumor size, months from diagnosis to treatment, surgery, radiation and chemotherapy were the independent prognostic factors for OS, and the multivariate analysis results were presented by forest plot (Figure 2).
Table 2 Univariate Cox regression analysis of prognostic factors for Training cohort.
|
CSS
|
OS
|
Characteristics
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
Sex
|
|
|
|
|
Male
|
Reference
|
|
Reference
|
|
Female
|
0.92(0.86,0.98)
|
0.01
|
0.91(0.85-0.97)
|
0.004
|
Race
|
|
|
|
|
White
|
Reference
|
|
Reference
|
|
Black
|
1.31(1.16-1.47)
|
<0.001
|
0.99(0.86-1.13)
|
0.845
|
Other
|
0.87(0.78-0.97)
|
0.015
|
1.2(1.09-1.32)
|
<0.001
|
Marital status
|
|
|
|
|
Single
|
Reference
|
|
Reference
|
|
Married
|
0.71(0.64-0.79)
|
<0.001
|
0.86(0.77-0.96)
|
0.008
|
Divorced
|
0.9(0.78-1.04)
|
0.157
|
0.93(0.8-1.08)
|
0.323
|
Other
|
0.99(0.89-1.11)
|
0.9
|
0.78(0.69-0.89)
|
<0.001
|
Grade
|
|
|
|
|
I
|
Reference
|
|
Reference
|
|
II
|
1.19(1.05-1.35)
|
0.008
|
0.85(0.76-0.94)
|
0.002
|
III
|
1.85(1.6-2.14)
|
<0.001
|
0.62(0.54-0.72)
|
<0.001
|
IV
|
2.07(1.58-2.7)
|
<0.001
|
0.63(0.44-0.91)
|
0.013
|
T stage
|
|
|
|
|
T1
|
Reference
|
|
Reference
|
|
T2
|
1.27(1.11-1.45)
|
<0.001
|
0.86(0.78-0.96)
|
0.006
|
T3
|
2.17(1.93-2.44)
|
<0.001
|
1.09(0.99-1.19)
|
0.068
|
T4
|
4.4(3.82-5.06)
|
<0.001
|
1.44(1.23-1.67)
|
<0.001
|
N stage
|
|
|
|
|
N0
|
Reference
|
|
Reference
|
|
N1
|
1.52(1.42-1.64)
|
<0.001
|
1.22(1.14-1.31)
|
<0.001
|
N2
|
2.61(2.38-2.86)
|
<0.001
|
0.87(0.76-1)
|
0.044
|
TNM Stage
|
|
|
|
|
Ⅰ
|
Reference
|
|
Reference
|
|
Ⅱ
|
1.81(1.65-1.98)
|
<0.001
|
1.17(1.08-1.27)
|
<0.001
|
Ⅲ
|
2.46(2.26-2.68)
|
<0.001
|
1.23(1.14-1.33)
|
<0.001
|
CEA
|
|
|
|
|
Positive
|
Reference
|
|
Reference
|
|
Negative
|
0.57(0.53-0.61)
|
<0.001
|
0.92(0.86-0.98)
|
0.015
|
Borderline
|
0.85(0.6-1.2)
|
0.348
|
0.78(0.53-1.14)
|
0.2
|
Tumor size
|
|
|
|
|
<3
|
Reference
|
|
Reference
|
|
3-5
|
1.39(1.27-1.51)
|
<0.001
|
0.94(0.87-1.02)
|
0.147
|
5-7
|
1.74(1.58-1.91)
|
<0.001
|
1.07(0.97-1.16)
|
0.163
|
≥7
|
2.22(2-2.46)
|
<0.001
|
1.07(0.96-1.19)
|
0.219
|
Months.from.diagnosis.to.treatment
|
1(0.98-1.03)
|
0.746
|
1.12(1.1-1.15)
|
<0.001
|
Surgery
|
|
|
|
|
No
|
Reference
|
|
Reference
|
|
Yes
|
0.39(0.35-0.42)
|
<0.001
|
0.56(0.51-0.62)
|
<0.001
|
Radiation
|
|
|
|
|
No
|
Reference
|
|
Reference
|
|
Yes
|
1.09(1.02-1.16)
|
0.009
|
1.27(1.2-1.34)
|
<0.001
|
Chemotherapy
|
|
|
|
|
No
|
Reference
|
|
Reference
|
|
Yes
|
1.05(0.98-1.12)
|
0.154
|
1.39(1.31-1.47)
|
<0.001
|
Table 3 Multivariate Cox regression analysis of prognostic factors for Training cohort.
|
CSS
|
OS
|
Characteristics
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
Sex
|
|
|
|
|
Male
|
Reference
|
|
Reference
|
|
Female
|
0.92(0.86-0.98)
|
0.01
|
0.92(0.87-0.97)
|
0.004
|
Race
|
|
|
|
|
White
|
Reference
|
|
Reference
|
|
Black
|
1.31(1.16-1.47)
|
<0.001
|
1.01(0.9-1.13)
|
0.882
|
Other
|
0.87(0.78-0.97)
|
0.015
|
1.21(1.12-1.31)
|
<0.001
|
Marital status
|
|
|
|
|
Single
|
Reference
|
|
Reference
|
|
Married
|
0.71(0.64-0.79)
|
<0.001
|
0.84(0.77-0.92)
|
<0.001
|
Divorced
|
0.9(0.78-1.04)
|
0.157
|
0.91(0.8-1.03)
|
0.124
|
Other
|
0.99(0.89-1.11)
|
0.9
|
0.76(0.69-0.85)
|
<0.001
|
Grade
|
|
|
|
|
I
|
Reference
|
|
Reference
|
|
II
|
1.19(1.05-1.35)
|
0.008
|
0.84(0.76-0.91)
|
<0.001
|
III
|
1.85(1.6-2.14)
|
<0.001
|
0.6(0.53-0.67)
|
<0.001
|
IV
|
2.07(1.58-2.7)
|
<0.001
|
0.6(0.44-0.82)
|
0.002
|
T stage
|
|
|
|
|
T1
|
Reference
|
|
Reference
|
|
T2
|
1.27(1.11-1.45)
|
<0.001
|
0.89(0.81-0.97)
|
0.006
|
T3
|
2.17(1.93-2.44)
|
<0.001
|
1.09(1.01-1.18)
|
0.021
|
T4
|
4.4(3.82-5.06)
|
<0.001
|
1.4(1.23-1.58)
|
<0.001
|
N stage
|
|
|
|
|
N0
|
Reference
|
|
Reference
|
|
N1
|
1.52(1.42-1.64)
|
<0.001
|
1.22(1.15-1.3)
|
<0.001
|
N2
|
2.61(2.38-2.86)
|
<0.001
|
0.88(0.79-0.98)
|
0.023
|
TNM Stage
|
|
|
|
|
Ⅰ
|
Reference
|
|
Reference
|
|
Ⅱ
|
1.81(1.65-1.98)
|
<0.001
|
1.15(1.08-1.23)
|
<0.001
|
Ⅲ
|
2.46(2.26-2.68)
|
<0.001
|
1.22(1.15-1.31)
|
<0.001
|
CEA
|
|
|
|
|
Positive
|
Reference
|
|
Reference
|
|
Negative
|
0.57(0.53-0.61)
|
<0.001
|
0.92(0.87-0.97)
|
0.003
|
Borderline
|
0.85(0.6-1.2)
|
0.348
|
0.73(0.53-1.02)
|
0.065
|
Tumor size
|
|
|
|
|
<3
|
Reference
|
|
Reference
|
|
3-5
|
1.39(1.27-1.51)
|
<0.001
|
0.96(0.9-1.03)
|
0.27
|
5-7
|
1.74(1.58-1.91)
|
<0.001
|
1.08(1-1.17)
|
0.038
|
≥7
|
2.22(2-2.46)
|
<0.001
|
1.11(1.01-1.21)
|
0.027
|
Months.from.diagnosis.to.treatment
|
1(0.98-1.03)
|
0.746
|
1.14(1.12-1.16)
|
< 0.001
|
Surgery
|
|
|
|
|
No
|
Reference
|
|
Reference
|
|
Yes
|
0.39(0.35-0.42)
|
<0.001
|
0.56(0.51-0.62)
|
<0.001
|
Radiation
|
|
|
|
|
No
|
Reference
|
|
Reference
|
|
Yes
|
1.09(1.02-1.16)
|
0.009
|
1.27(1.2-1.34)
|
<0.001
|
Chemotherapy
|
|
|
|
|
No
|
Reference
|
|
Reference
|
|
Yes
|
1.05(0.98-1.12)
|
0.154
|
1.39(1.31-1.47)
|
<0.001
|
3.3 Nomogram construction
LASSO regression analysis was performed to identify the potential prognostic factors. Figure 3 shows that when the optimal lambda value was 0.02, marital status, grade, T stage, N stage, CEA, tumor size, surgery and chemotherapy were associated with CSS. And when the optimal lambda value was 0.04, grade, chemotherapy and months from diagnosis to treatment, were associated with OS.
Based on multivariate analysis results and LASSO regression analysis, eight prognostic factors including marital status, grade, T stage, N stage, CEA, tumor size, surgery and chemotherapy were used to establish the nomogram of CSS (Figure 4A), And three prognostic factors including grade, chemotherapy and months from diagnosis to treatment were used to establish the nomogram of OS (Figure 4B), These nomograms were adopted to predict the 1-, 3-, and 5-year survival rates of training cohort. In a nomogram, the score of each value level of each variable was assigned according to its contribution to the outcome; then, each score was added to obtain the total score; finally, the predicted value of each individual outcome event was calculated through the function conversion relation between the total score and the survival probability.
3.4 Nomogram validation
The nomogram was assessed using the area under the curve (AUC) and concordance index (C-index). In the training cohort, as shown in (Figure 5), the C-index of CSS and OS prediction nomograms were 0.609 (95%CI, 0.598 to 0.619) and 0.697 (95%CI, 0.686 to 0.708) , and the AUC in predicting 1-, 3- and 5-year CSS were 0.746, 0.741 and 0.731, the AUC in predicting 1-, 3- and 5-year OS was 0.636, 0.642 and 0.633. Respectively, while in the validation cohort the C-index of CSS and OS prediction nomograms were 0.682 (95%CI, 0.665 to 0.698) and 0.605 (95%CI, 0.589 to 0.621), and in predicting 1-, 3-, and 5-year CSS were 0.732, 0.720 and 0.710, the AUC in predicting 1-, 3-, and 5-year OS was 0.609, 0.633 and 0.631(Figure 6). Calibration curves of survival rates at 1, 3, and 5 years in the training cohort(Figure 7) and validation cohort (Figure 8) showed satisfactory internal modelfitting capabilities. Excellent discrimination and calibration demonstrated the accuracy of the prognostic model.
3.5 Risk stratification
According to the nomograms we calculated the risk score of each patient. Meanwhile, the cutoff value of total score of CSS was 161 points, whereas that of OS was 43 points, as calculated by the td-ROC curve analysis. Later, patients were divided into low- and high-risk groups according to the cutoff values. The survival of high-risk patients from training cohort and validation cohort was poorer than that of low-risk patients, either based on the OS or CSS nomogram (Figure 9).
3.6 Subgroup Analyses from cherapy
Furthermore, we explore the impact of different treatments on survival and prognosis. Based on the treatment received by the patients, they were divided into a surgery group and a combined group. In the surgery cohort patients were received rectal cancer surgery only, while in combined group patients were received surgery plus radiation or chemotherapy. The detailed clinicopathologic characteristics of the patients in the two groups before or after PSM are shown in Table 4. Before PSM, the surgery group showed significantly better CSS and OS than the combined group(CSS:p < 0.001, OS: p < 0.001, respectively ; Figure 10A and 10B), After 1:1 matching, 2234 patients in the surgery group were matched and compared with 2234 patients in the combined group. No demographic variables with significant differences were included (p > 0.05).
After eliminating the differences in covariates that might affect CSS and OS by using PSM, we found that patients in the surgery group achieved no significantly better CSS and OS than those in the combined group (CSS:p < 0.073, OS: p < 0.057, respectively ; Figure 10C and 10D). We performed univariate and multivariate analyses to investigate the prognostic factors that could predict CSS and OS in the before PSM group and after PSM group. As shown in Table 5, univariate analyses revealed that sex, age, race, marital status, grade, CEA, tumor size, T stage, N stage, TNM stage and cherapy were important factors affecting CSS, and sex, age, race, marital status, grade, CEA, tumor size, T stage, months from diagnosis to treatment and cherapy were important factors affecting OS. And in the multivariate analysis, sex, marital status, grade, tumor size, CEA, T stage N stage, TNM stage and cherapy were independent prognostic factors of CSS, while sex, race, marital status, grade, tumor size, cherapy and months from diagnosis to treatment were independent prognostic factors of OS. The multivariate analysis results were presented by forest plot (Figure 11A and 11B). But in the after PSM cohort, as shown in Table 6, univariate analyses revealed that sex, age, marital status, Grade, CEA, Tumor size, T stage, N stage, TNM stage were important factors affecting CSS, and age, Grade, T stage, Months from diagnosis to treatment were important factors affecting OS. And in the multivariate analysis, grade, T stage, N stage, TNM stage, CEA, tumor size were independent prognostic factors of CSS, while race, grade, tumor size, months from diagnosis to treatment were independent prognostic factors of OS, the multivariate analysis results were presented by a forest plot (Figure 11C and 11D).
Table 4 Baseline characteristics of two groups
|
Data before PSM
|
Data after PSM
|
Variables
|
Overall cohort
(n = 5846)
|
Surgery
(n=4620)
|
Combined
(n=1226)
|
p value
|
Overall cohort
(n = 2234)
|
Surgery
(n=1117)
|
Combined
(n=1117)
|
p value
|
Sex, n (%)
|
|
|
|
0.014
|
|
|
|
0.491
|
Male
|
3305(56.5)
|
2574(55.7)
|
731(59.6)
|
|
1322(59.2)
|
669(59.9)
|
653(58.5)
|
|
Female
|
2541(43.5)
|
2046(44.3)
|
495(40.4)
|
|
912(40.8)
|
448(40.1)
|
464(41.5)
|
|
Age, Median (IQR)
|
76.0(70.0, 82.0)
|
76.5(70.0, 83.0)
|
75.0(69.2, 80.0)
|
<0.001
|
75.0(70.0, 81.0)
|
75.0(70.0, 82.0)
|
75.0(70.0, 81.0)
|
0.545
|
Race, n (%)
|
|
|
|
0.003
|
|
|
|
0.939
|
White
|
4899(83.8)
|
3906(84.5)
|
993(81)
|
|
1814(81.2)
|
904(80.9)
|
910(81.5)
|
|
Black
|
375( 6.4)
|
273(5.9)
|
102(8.3)
|
|
180( 8.1)
|
92(8.2)
|
88(7.9)
|
|
Other
|
572( 9.8)
|
441(9.5)
|
131(10.7)
|
|
240(10.7)
|
121(10.8)
|
119(10.7)
|
|
Year.of.diagnos.2, n (%)
|
|
|
|
<0.001
|
|
|
|
0.609
|
2010-2011
|
2366(40.5)
|
1922(41.6)
|
444(36.2)
|
|
891(39.9)
|
457(40.9)
|
434(38.9)
|
|
2012-2013
|
2012(34.4)
|
1598(34.6)
|
414(33.8)
|
|
748(33.5)
|
367(32.9)
|
381(34.1)
|
|
2014-2015
|
1468(25.1)
|
1100(23.8)
|
368(30)
|
|
595(26.6)
|
293(26.2)
|
302(27)
|
|
Marital status, n (%)
|
|
|
|
<0.001
|
|
|
|
0.63
|
Single
|
531( 9.1)
|
402(8.7)
|
129(10.5)
|
|
213( 9.5)
|
98(8.8)
|
115(10.3)
|
|
Married
|
3137(53.7)
|
2428(52.6)
|
709(57.8)
|
|
1245(55.7)
|
625(56)
|
620(55.5)
|
|
Divorced
|
459( 7.9)
|
363(7.9)
|
96(7.8)
|
|
196( 8.8)
|
102(9.1)
|
94(8.4)
|
|
Other
|
1719(29.4)
|
1427(30.9)
|
292(23.8)
|
|
580(26.0)
|
292(26.1)
|
288(25.8)
|
|
Grade, n (%)
|
|
|
|
<0.001
|
|
|
|
0.861
|
Ⅰ
|
516( 8.8)
|
440(9.5)
|
76(6.2)
|
|
150( 6.7)
|
77(6.9)
|
73(6.5)
|
|
Ⅱ
|
4516(77.2)
|
3595(77.8)
|
921(75.1)
|
|
1676(75.0)
|
830(74.3)
|
846(75.7)
|
|
Ⅲ
|
736(12.6)
|
541(11.7)
|
195(15.9)
|
|
359(16.1)
|
186(16.7)
|
173(15.5)
|
|
Ⅳ
|
78( 1.3)
|
44(1)
|
34(2.8)
|
|
49( 2.2)
|
24(2.1)
|
25(2.2)
|
|
CEA, n (%)
|
|
|
|
<0.001
|
|
|
|
0.951
|
Positive
|
1988(34.0)
|
1494(32.3)
|
494(40.3)
|
|
900(40.3)
|
452(40.5)
|
448(40.1)
|
|
Negative
|
3818(65.3)
|
3093(66.9)
|
725(59.1)
|
|
1321(59.1)
|
659(59)
|
662(59.3)
|
|
Borderline
|
40( 0.7)
|
33(0.7)
|
7(0.6)
|
|
13( 0.6)
|
6(0.5)
|
7(0.6)
|
|
Tumor size, n (%)
|
|
|
|
<0.001
|
|
|
|
0.651
|
<3
|
2071(35.4)
|
1758(38.1)
|
313(25.5)
|
|
556(24.9)
|
280(25.1)
|
276(24.7)
|
|
3-5
|
2140(36.6)
|
1651(35.7)
|
489(39.9)
|
|
919(41.1)
|
469(42)
|
450(40.3)
|
|
5-7
|
1109(19.0)
|
812(17.6)
|
297(24.2)
|
|
531(23.8)
|
262(23.5)
|
269(24.1)
|
|
≥7
|
526( 9.0)
|
399(8.6)
|
127(10.4)
|
|
228(10.2)
|
106(9.5)
|
122(10.9)
|
|
T stage, n (%)
|
|
|
|
<0.001
|
|
|
|
0.506
|
T1
|
1316(22.5)
|
1206(26.1)
|
110(9)
|
|
229(10.3)
|
120(10.7)
|
109(9.8)
|
|
T2
|
1849(31.6)
|
1613(34.9)
|
236(19.2)
|
|
446(20.0)
|
230(20.6)
|
216(19.3)
|
|
T3
|
2362(40.4)
|
1620(35.1)
|
742(60.5)
|
|
1335(59.8)
|
650(58.2)
|
685(61.3)
|
|
T4
|
319( 5.5)
|
181(3.9)
|
138(11.3)
|
|
224(10.0)
|
117(10.5)
|
107(9.6)
|
|
N stage, n (%)
|
|
|
|
<0.001
|
|
|
|
0.277
|
N0
|
4322(73.9)
|
3740(81)
|
582(47.5)
|
|
1117(50.0)
|
540(48.3)
|
577(51.7)
|
|
N1
|
1005(17.2)
|
580(12.6)
|
425(34.7)
|
|
735(32.9)
|
377(33.8)
|
358(32.1)
|
|
N2
|
519( 8.9)
|
300(6.5)
|
219(17.9)
|
|
382(17.1)
|
200(17.9)
|
182(16.3)
|
|
TNM Stage, n (%)
|
|
|
|
<0.001
|
|
|
|
0.074
|
Ⅰ
|
2826(48.3)
|
2623(56.8)
|
203(16.6)
|
|
419(18.8)
|
216(19.3)
|
203(18.2)
|
|
Ⅱ
|
1496(25.6)
|
1117(24.2)
|
379(30.9)
|
|
698(31.2)
|
324(29)
|
374(33.5)
|
|
Ⅲ
|
1524(26.1)
|
880(19)
|
644(52.5)
|
|
1117(50.0)
|
577(51.7)
|
540(48.3)
|
|
Months.from.diagnosis.to.treatment,Mean ± SD
|
1.1 ± 1.3
|
1.1 ± 1.3
|
1.1 ± 1.2
|
0.811
|
1.1 ± 1.3
|
1.1 ± 1.4
|
1.1 ± 1.2
|
0.452
|
Table 5 Univariate and multivariate Cox regression model analysis of before PSM cohort between the surgery group and the combined group.
|
Univariate analysis
|
Multivariate analysis
|
|
CSS
|
|
OS
|
CSS
|
OS
|
Characteristics
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
Sex
|
|
|
|
|
|
0.023
|
|
<0.001
|
Male
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Female
|
0.89(0.81-0.98)
|
0.023
|
0.86(0.79-0.93)
|
< 0.001
|
0.89(0.81-0.98)
|
0.023
|
0.86(0.79-0.93)
|
<0.001
|
Race
|
|
|
|
|
|
0.777
|
|
<0.001
|
White
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Black
|
1.34(1.12-1.61)
|
0.001
|
1.07(0.88-1.3)
|
0.517
|
1.34(1.12-1.61)
|
0.001
|
1.07(0.88-1.3)
|
0.517
|
Other
|
0.94(0.8-1.11)
|
0.489
|
1.28(1.12-1.45)
|
< 0.001
|
0.94(0.8-1.11)
|
0.489
|
1.28(1.12-1.45)
|
<0.001
|
Marital status
|
|
|
|
|
|
<0.001
|
|
0.005
|
Single
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Married
|
0.74(0.62-0.87)
|
< 0.001
|
0.93(0.8-1.08)
|
0.343
|
0.74(0.62-0.87)
|
<0.001
|
0.93(0.8-1.08)
|
0.343
|
Divorced
|
0.87(0.69-1.1)
|
0.243
|
1.03(0.84-1.27)
|
0.752
|
0.87(0.69-1.1)
|
0.243
|
1.03(0.84-1.27)
|
0.752
|
Other
|
1.05(0.88-1.24)
|
0.607
|
0.8(0.68-0.95)
|
0.01
|
1.05(0.88-1.24)
|
0.607
|
0.8(0.68-0.95)
|
0.01
|
Grade
|
|
|
|
|
|
<0.001
|
|
<0.001
|
I
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
II
|
1.34(1.1-1.63)
|
0.004
|
0.8(0.7-0.92)
|
0.001
|
1.34(1.1-1.63)
|
0.004
|
0.8(0.7-0.92)
|
0.001
|
III
|
2.36(1.89-2.94)
|
<0.001
|
0.58(0.47-0.7)
|
< 0.001
|
2.36(1.89-2.94)
|
<0.001
|
0.58(0.47-0.7)
|
<0.001
|
IV
|
3.23(2.22-4.7)
|
<0.001
|
0.53(0.3-0.96)
|
0.034
|
3.23(2.22-4.7)
|
<0.001
|
0.53(0.3-0.96)
|
0.034
|
T stage
|
|
|
|
|
|
<0.001
|
|
0.072
|
T1
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
T2
|
1.71(1.44-2.03)
|
<0.001
|
0.81(0.73-0.9)
|
< 0.001
|
1.71(1.44-2.03)
|
<0.001
|
0.81(0.73-0.9)
|
<0.001
|
T3
|
3.68(3.14-4.31)
|
<0.001
|
0.85(0.77-0.95)
|
0.004
|
3.68(3.14-4.31)
|
<0.001
|
0.85(0.77-0.95)
|
0.004
|
T4
|
7.53(6.13-9.26)
|
<0.001
|
1.19(0.93-1.54)
|
0.172
|
7.53(6.13-9.26)
|
<0.001
|
1.19(0.93-1.54)
|
0.172
|
N stage
|
|
|
|
|
|
<0.001
|
|
0.61
|
N0
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
N1
|
2.3(2.05-2.58)
|
<0.001
|
1.06(0.93-1.2)
|
0.36
|
2.3(2.05-2.58)
|
<0.001
|
1.06(0.93-1.2)
|
0.36
|
N2
|
3.82(3.35-4.37)
|
<0.001
|
0.87(0.71-1.07)
|
0.195
|
3.82(3.35-4.37)
|
<0.001
|
0.87(0.71-1.07)
|
0.195
|
TNM Stage
|
|
|
|
|
|
<0.001
|
|
0.708
|
Ⅰ
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Ⅱ
|
2.42(2.14-2.74)
|
<0.001
|
0.95(0.86-1.06)
|
0.019
|
2.42(2.14-2.74)
|
<0.001
|
0.95(0.86-1.06)
|
0.384
|
Ⅲ
|
3.92(3.49-4.41)
|
<0.001
|
0.99(0.88-1.11)
|
<0.001
|
3.92(3.49-4.41)
|
<0.001
|
0.99(0.88-1.11)
|
0.899
|
CEA
|
|
|
|
|
|
<0.001
|
|
0.703
|
Positive
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Negative
|
0.52(0.47-0.57)
|
< 0.001
|
1.02(0.93-1.13)
|
0.659
|
0.52(0.47-0.57)
|
<0.001
|
1.02(0.93-1.13)
|
0.659
|
Borderline
|
1.17(0.72-1.89)
|
0.525
|
0.93(0.48-1.8)
|
0.831
|
1.17(0.72-1.89)
|
0.525
|
0.93(0.48-1.8)
|
0.831
|
Tumor size
|
|
|
|
|
|
<0.001
|
|
<0.001
|
<3
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
3-5
|
1.56(1.38-1.76)
|
<0.001
|
0.85(0.77-0.94)
|
0.001
|
1.56(1.38-1.76)
|
<0.001
|
0.85(0.77-0.94)
|
0.001
|
5-7
|
2.2(1.92-2.52)
|
<0.001
|
0.75(0.66-0.86)
|
< 0.001
|
2.2(1.92-2.52)
|
<0.001
|
0.75(0.66-0.86)
|
<0.001
|
≥7
|
2.56(2.17-3.01)
|
<0.001
|
0.72(0.6-0.87)
|
< 0.001
|
2.56(2.17-3.01)
|
<0.001
|
0.72(0.6-0.87)
|
<0.001
|
Months.from.diagnosis.to.treatment
|
1.01(0.97-1.05)
|
0.597
|
1.14(1.11-1.17)
|
<0.001
|
1.01(0.97-1.05)
|
0.597
|
1.14(1.11-1.17)
|
<0.001
|
Cherapy
|
|
|
|
|
|
<0.001
|
|
<0.001
|
Surgery
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Combined
|
1.52(1.36-1.69)
|
< 0.001
|
1.21(1.09-1.35)
|
<0.001
|
1.52(1.36-1.69)
|
<0.001
|
1.21(1.09-1.35)
|
<0.001
|
Table 6 Univariate and multivariate Cox regression model analysis of after PSM cohort between the surgery group and the combined group.
|
Univariate analysis
|
Multivariate analysis
|
|
CSS
|
OS
|
CSS
|
OS
|
Characteristics
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
HR(95% CI)
|
P value
|
Sex
|
|
|
|
|
|
0.036
|
|
0.148
|
Male
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Female
|
0.86(0.75-0.99)
|
0.036
|
0.9(0.77-1.04)
|
0.148
|
0.86(0.75-0.99)
|
0.036
|
0.9(0.77-1.04)
|
0.148
|
Race
|
|
|
|
|
|
0.762
|
|
0.022
|
White
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Black
|
1.24(0.98-1.58)
|
0.077
|
1.07(0.78-1.45)
|
0.68
|
1.24(0.98-1.58)
|
0.077
|
1.07(0.78-1.45)
|
0.68
|
Other
|
0.97(0.78-1.21)
|
0.801
|
1.29(1.04-1.59)
|
0.02
|
0.97(0.78-1.21)
|
0.801
|
1.29(1.04-1.59)
|
0.02
|
Marital status
|
|
|
|
|
|
0.054
|
|
0.431
|
Single
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Married
|
0.71(0.57-0.89)
|
0.003
|
1.04(0.8-1.37)
|
0.765
|
0.71(0.57-0.89)
|
0.003
|
1.04(0.8-1.37)
|
0.765
|
Divorced
|
0.87(0.64-1.18)
|
0.365
|
1.09(0.75-1.58)
|
0.65
|
0.87(0.64-1.18)
|
0.365
|
1.09(0.75-1.58)
|
0.65
|
Other
|
0.94(0.74-1.19)
|
0.586
|
0.94(0.69-1.27)
|
0.688
|
0.94(0.74-1.19)
|
0.586
|
0.94(0.69-1.27)
|
0.688
|
Grade
|
|
|
|
|
|
<0.001
|
|
<0.001
|
I
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
II
|
1.05(0.79-1.4)
|
0.743
|
0.77(0.59-1.01)
|
0.055
|
1.05(0.79-1.4)
|
0.743
|
0.77(0.59-1.01)
|
0.055
|
III
|
1.61(1.17-2.2)
|
0.003
|
0.54(0.38-0.76)
|
< 0.001
|
1.61(1.17-2.2)
|
0.003
|
0.54(0.38-0.76)
|
<0.001
|
IV
|
2.31(1.44-3.71)
|
< 0.001
|
0.42(0.15-1.15)
|
0.091
|
2.31(1.44-3.71)
|
0.001
|
0.42(0.15-1.15)
|
0.091
|
T stage
|
|
|
|
|
|
<0.001
|
|
0.889
|
T1
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
T2
|
1.32(0.95-1.83)
|
0.096
|
0.76(0.59-0.98)
|
0.034
|
1.32(0.95-1.83)
|
0.096
|
0.76(0.59-0.98)
|
0.034
|
T3
|
2.24(1.67-2.99)
|
< 0.001
|
0.8(0.64-1.01)
|
0.058
|
2.24(1.67-2.99)
|
<0.001
|
0.8(0.64-1.01)
|
0.058
|
T4
|
4.59(3.3-6.38)
|
< 0.001
|
1.17(0.82-1.67)
|
0.382
|
4.59(3.3-6.38)
|
<0.001
|
1.17(0.82-1.67)
|
0.382
|
N stage
|
|
|
|
|
|
|
|
0.181
|
N0
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
N1
|
1.49(1.28-1.74)
|
< 0.001
|
0.97(0.82-1.14)
|
0.688
|
1.49(1.28-1.74)
|
< 0.001
|
0.97(0.82-1.14)
|
0.688
|
N2
|
2.55(2.14-3.04)
|
< 0.001
|
0.83(0.65-1.07)
|
0.145
|
2.55(2.14-3.04)
|
< 0.001
|
0.83(0.65-1.07)
|
0.145
|
TNM Stage
|
|
|
|
|
|
<0.001
|
|
0.465
|
Ⅰ
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Ⅱ
|
1.81(1.43-2.29)
|
<0.001
|
1.03(0.84-1.25)
|
0.797
|
1.81(1.43-2.29)
|
<0.001
|
1.03(0.84-1.25)
|
0.797
|
Ⅲ
|
2.65(2.13-3.31)
|
<0.001
|
0.94(0.78-1.14)
|
0.543
|
2.65(2.13-3.31)
|
<0.001
|
0.94(0.78-1.14)
|
0.543
|
CEA
|
|
|
|
|
|
< 0.001
|
|
0.231
|
Positive
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Negative
|
0.63(0.55-0.72)
|
< 0.001
|
1.09(0.93-1.28)
|
0.289
|
0.63(0.55-0.72)
|
<0.001
|
1.09(0.93-1.28)
|
0.289
|
Borderline
|
2.04(1.01-4.11)
|
0.046
|
1.97(0.63-6.16)
|
0.244
|
2.04(1.01-4.11)
|
0.046
|
1.97(0.63-6.16)
|
0.244
|
Tumor size
|
|
|
|
|
|
< 0.001
|
|
0.019
|
<3
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
3-5
|
1.28(1.07-1.54)
|
0.007
|
0.89(0.74-1.06)
|
0.189
|
1.28(1.07-1.54)
|
0.007
|
0.89(0.74-1.06)
|
0.189
|
5-7
|
1.48(1.21-1.81)
|
< 0.001
|
0.8(0.65-0.99)
|
0.039
|
1.48(1.21-1.81)
|
< 0.001
|
0.8(0.65-0.99)
|
0.039
|
≥7
|
1.96(1.54-2.48)
|
< 0.001
|
0.76(0.56-1.03)
|
0.078
|
1.96(1.54-2.48)
|
< 0.001
|
0.76(0.56-1.03)
|
0.078
|
Months.from.diagnosis.to.treatment
|
1.02(0.96-1.07)
|
0.542
|
1.19(1.14-1.24)
|
< 0.001
|
1.02(0.96-1.07)
|
0.542
|
1.19(1.14-1.24)
|
<0.001
|
Cherapy
|
|
|
|
|
|
0.073
|
|
0.059
|
Surgery
|
Reference
|
|
Reference
|
|
Reference
|
|
Reference
|
|
Combined
|
0.88(0.77-1.01)
|
0.073
|
1.15(0.99-1.34)
|
0.059
|
0.88(0.77-1.01)
|
0.073
|
1.15(0.99-1.34)
|
0.059
|