Retrospective Cohort Study
Copyright ©The Author(s) 2020.
World J Gastrointest Oncol. Nov 15, 2020; 12(11): 1296-1310
Published online Nov 15, 2020. doi: 10.4251/wjgo.v12.i11.1296
Table 1 Patients’ characteristics according to primary tumor resection status

Total
PTR
No PTR
P value
Age0.0065
n466313153
Mean (std)64.0 (11.6)63.0 (11.1)66.1 (12.4)
Median [min-max]65.0 (24.0-92.0)63.0 (29.0-90.0)67.0 (24.0-92.0)
Gender0.9563
Male255 (54.7%)171 (54.6%)84 (54.9%)
Female211 (45.3%)142 (45.4%)69 (45.1%)
Primary tumor location0.0010
Left colon + sigmoid203 (43.6%)153 (48.9%)50 (32.7%)
Right colon + transverse colon174 (37.3%)112 (35.8%)62 (40.5%)
Rectum89 (19.1%)48 (15.3%)41 (26.8%)
PS0.0296
0-1300 (83.6%)202 (86.7%)98 (77.8%)
2-459 (16.4%)31 (13.3%)28 (22.2%)
Missing values1078027
Number of metastatic sites0.1080
1283 (60.7%)200 (63.9%)83 (54.2%)
2133 (28.5%)84 (26.8%)49 (32.0%)
> 250 (10.7%)29 (9.3%)21 (13.7%)
Metastatic sites
Liver0.9689
No89 (19.2%)60 (19.2%)29 (19.1%)
Yes375 (80.8%)252 (80.8%)123 (80.9%)
Missing values211
Lung0.0206
No342 (73.9%)240 (77.2%)102 (67.1%)
Yes121 (26.1%)71 (22.8%)50 (32.9%)
Missing values321
Peritoneum0.8377
No356 (76.9%)240 (77.2%)116 (76.3%)
Yes107 (23.1%)71 (22.8%)36 (23.7%)
Missing values321
Other0.2531
No361 (78.1%)247 (79.7%)114 (75.0%)
Yes101 (21.9%)63 (20.3%)38 (25.0%)
Missing values431
KRAS mutation0.5956
No202 (56.7%)143 (57.7%)59 (54.6%)
Yes154 (43.3%)105 (42.3%)49 (45.4%)
Missing values1106545
BRAF mutation0.3218
No265 (90.1%)188 (91.3%)77 (87.5%)
Yes29 (9.9%)18 (8.7%)11 (12.5%)
Missing values17210765
CEA0.0002
≤ 200251 (68.6%)177 (75.3%)74 (56.5%)
> 200115 (31.4%)58 (24.7%)57 (43.5%)
Missing values1007822
LDH< 0.0001
≤ 254175 (53.2%)130 (62.2%)45 (37.5%)
> 254154 (46.8%)79 (37.8%)75 (62.5%)
Missing values13710433
Leukocytes > 100000.0014
No256 (70.9%)175 (76.8%)81 (60.9%)
Yes105 (29.1%)53 (23.2%)52 (39.1%)
Missing values1058520
Alkaline phosphatase > 3000.0008
No261 (77.9%)179 (83.6%)82 (67.8%)
Yes74 (22.1%)35 (16.4%)39 (32.2%)
Missing values1319932
Oxaliplatin0.3478
No35 (7.5%)21 (6.7%)14 (9.2%)
Yes431 (92.5%)292 (93.3%)139 (90.8%)
5 FU or capecitabine1.0000
No3 (0.6%)2 (0.6%)1 (0.7%)
Yes463 (99.4%)311 (99.4%)152 (99.3%)
Irinotecan0.1278
No105 (22.6%)64 (20.5%)41 (26.8%)
Yes360 (77.4%)248 (79.5%)112 (73.2%)
Missing values110
Bevacizumab0.1978
No150 (32.4%)95 (30.4%)55 (36.4%)
Yes313 (67.6%)217 (69.6%)96 (63.6%)
Missing values312
EGFR inhibitors0.2681
No267 (57.5%)174 (55.8%)93 (61.2%)
Yes197 (42.5%)138 (44.2%)59 (38.8%)
Missing values211
1st line chemotherapy regimen0.7568
Mono-chemotherapy48 (10.4%)32 (10.3%)16 (10.5%)
Bi-chemotherapy326 (70.6%)216 (69.7%)110 (72.4%)
Tri- chemotherapy88 (19.0%)62 (20.0%)26 (17.1%)
Missing values431
Lung or Liver surgery or radio-frequency< 0.0001
No326 (70.4%)178 (57.4%)148 (96.7%)
Yes137 (29.6%)132 (42.6%)5 (3.3%)
Missing values330
Table 2 Univariate Cox model

HR
95%CI
P value
Agen = 4660.0714
> 65 yr vs ≤ 65 yr 1.209[0.984-1.485]
Gendern = 4660.3701
Female vs male1.099[0.894-1.350]
Tumor locationn = 4660.0022
Rectum vs left colon + sigmoid1.019[0.767-1.355]
Right colon + transverse colon vs Left colon + sigmoid1.464[1.16-1.841]
Number of metastatic sitesn = 4660.0035
2 vs 11.219[0.965-1.539]
> 2 vs 11.749[1.245-2.455]
Number of metastatic sitesn = 4660.0084
≥ 2 vs 11.328[1.076-1.641]
Liver metastasesn = 4640.8836
Yes vs No1.020[0.782-1.330]
Lung metastasesn = 4630.6435
Yes vs No1.057[0.835-1.338]
Peritoneum metastasesn = 4630.0619
Yes vs No1.260[0.989-1.606]
Other metastasesn = 4620.0114
Yes vs No1.377[1.075-1.765]
KRAS mutationn = 3560.0696
Yes vs No1.256[0.982-1.606]
BRAF mutationn = 294< 0.0001
Yes vs No2.276[1.511-3.429]
CEAn = 366< 0.0001
> 200 vs ≤ 2001.654[1.290-2.120]
LDHn = 329< 0.0001
> 254 vs ≤ 2542.022[1.574-2.596]
Leukocytes > 10000n = 3610.0016
Yes vs No1.506[1.168-1.941]
Alkaline phosphatase > 300n = 335< 0.0001
Yes vs No2.272[1.713-3.014]
PTRn = 466< 0.0001
Yes vs No0.313[0.250-0.392]
Oxaliplatinn = 466< 0.0001
Yes vs No0.361[0.248-0.524]
Irinotecann = 4650.112
Yes vs No0.807[0.619-1.051]
5 FU or Capecitabinen = 4660.2869
Yes vs No0.539[0.173-1.682]
Bevacizumabn = 4630.0117
Yes vs No0.750[0.599-0.938]
EGFR inhibitorsn = 4640.0129
Yes vs No0.769[0.625-0.946]
1rst line chemotherapy regimenn = 4620.0080
Bi-chemotherapy vs Mono-chemotherapy0.682[0.496-0.937]
Tri-chemotherapy vs Mono-chemotherapy0.543[0.368-0.799]
Lung or liver surgery or radio-frequencyn = 463< 0.0001
Yes vs No0.302[0.235-0.388]