Influence of primary tumor location and resection on survival in metastatic colorectal cancer

Table 1 Patients’ characteristics according to primary tumor resection status

	Total	PTR	No PTR	P value
Age				0.0065
n	466	313	153
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)
Gender				0.9563
Male	255 (54.7%)	171 (54.6%)	84 (54.9%)
Female	211 (45.3%)	142 (45.4%)	69 (45.1%)
Primary tumor location				0.0010
Left colon + sigmoid	203 (43.6%)	153 (48.9%)	50 (32.7%)
Right colon + transverse colon	174 (37.3%)	112 (35.8%)	62 (40.5%)
Rectum	89 (19.1%)	48 (15.3%)	41 (26.8%)
PS				0.0296
0-1	300 (83.6%)	202 (86.7%)	98 (77.8%)
2-4	59 (16.4%)	31 (13.3%)	28 (22.2%)
Missing values	107	80	27
Number of metastatic sites				0.1080
1	283 (60.7%)	200 (63.9%)	83 (54.2%)
2	133 (28.5%)	84 (26.8%)	49 (32.0%)
> 2	50 (10.7%)	29 (9.3%)	21 (13.7%)
Metastatic sites
Liver				0.9689
No	89 (19.2%)	60 (19.2%)	29 (19.1%)
Yes	375 (80.8%)	252 (80.8%)	123 (80.9%)
Missing values	2	1	1
Lung				0.0206
No	342 (73.9%)	240 (77.2%)	102 (67.1%)
Yes	121 (26.1%)	71 (22.8%)	50 (32.9%)
Missing values	3	2	1
Peritoneum				0.8377
No	356 (76.9%)	240 (77.2%)	116 (76.3%)
Yes	107 (23.1%)	71 (22.8%)	36 (23.7%)
Missing values	3	2	1
Other				0.2531
No	361 (78.1%)	247 (79.7%)	114 (75.0%)
Yes	101 (21.9%)	63 (20.3%)	38 (25.0%)
Missing values	4	3	1
KRAS mutation				0.5956
No	202 (56.7%)	143 (57.7%)	59 (54.6%)
Yes	154 (43.3%)	105 (42.3%)	49 (45.4%)
Missing values	110	65	45
BRAF mutation				0.3218
No	265 (90.1%)	188 (91.3%)	77 (87.5%)
Yes	29 (9.9%)	18 (8.7%)	11 (12.5%)
Missing values	172	107	65
CEA				0.0002
≤ 200	251 (68.6%)	177 (75.3%)	74 (56.5%)
> 200	115 (31.4%)	58 (24.7%)	57 (43.5%)
Missing values	100	78	22
LDH				< 0.0001
≤ 254	175 (53.2%)	130 (62.2%)	45 (37.5%)
> 254	154 (46.8%)	79 (37.8%)	75 (62.5%)
Missing values	137	104	33
Leukocytes > 10000				0.0014
No	256 (70.9%)	175 (76.8%)	81 (60.9%)
Yes	105 (29.1%)	53 (23.2%)	52 (39.1%)
Missing values	105	85	20
Alkaline phosphatase > 300				0.0008
No	261 (77.9%)	179 (83.6%)	82 (67.8%)
Yes	74 (22.1%)	35 (16.4%)	39 (32.2%)
Missing values	131	99	32
Oxaliplatin				0.3478
No	35 (7.5%)	21 (6.7%)	14 (9.2%)
Yes	431 (92.5%)	292 (93.3%)	139 (90.8%)
5 FU or capecitabine				1.0000
No	3 (0.6%)	2 (0.6%)	1 (0.7%)
Yes	463 (99.4%)	311 (99.4%)	152 (99.3%)
Irinotecan				0.1278
No	105 (22.6%)	64 (20.5%)	41 (26.8%)
Yes	360 (77.4%)	248 (79.5%)	112 (73.2%)
Missing values	1	1	0
Bevacizumab				0.1978
No	150 (32.4%)	95 (30.4%)	55 (36.4%)
Yes	313 (67.6%)	217 (69.6%)	96 (63.6%)
Missing values	3	1	2
EGFR inhibitors				0.2681
No	267 (57.5%)	174 (55.8%)	93 (61.2%)
Yes	197 (42.5%)	138 (44.2%)	59 (38.8%)
Missing values	2	1	1
1st line chemotherapy regimen				0.7568
Mono-chemotherapy	48 (10.4%)	32 (10.3%)	16 (10.5%)
Bi-chemotherapy	326 (70.6%)	216 (69.7%)	110 (72.4%)
Tri- chemotherapy	88 (19.0%)	62 (20.0%)	26 (17.1%)
Missing values	4	3	1
Lung or Liver surgery or radio-frequency				< 0.0001
No	326 (70.4%)	178 (57.4%)	148 (96.7%)
Yes	137 (29.6%)	132 (42.6%)	5 (3.3%)
Missing values	3	3	0

PTR: Primary tumor resection; PS: Performance status; CEA: Carcinoembryonic antigen; LDH: Lactate dehydrogenase; EGDR: Epidermal growth factor.

Table 2 Univariate Cox model

		HR	95%CI	P value
Age	n = 466			0.0714
> 65 yr vs ≤ 65 yr		1.209	[0.984-1.485]
Gender	n = 466			0.3701
Female vs male		1.099	[0.894-1.350]
Tumor location	n = 466			0.0022
Rectum vs left colon + sigmoid		1.019	[0.767-1.355]
Right colon + transverse colon vs Left colon + sigmoid		1.464	[1.16-1.841]
Number of metastatic sites	n = 466			0.0035
2 vs 1		1.219	[0.965-1.539]
> 2 vs 1		1.749	[1.245-2.455]
Number of metastatic sites	n = 466			0.0084
≥ 2 vs 1		1.328	[1.076-1.641]
Liver metastases	n = 464			0.8836
Yes vs No		1.020	[0.782-1.330]
Lung metastases	n = 463			0.6435
Yes vs No		1.057	[0.835-1.338]
Peritoneum metastases	n = 463			0.0619
Yes vs No		1.260	[0.989-1.606]
Other metastases	n = 462			0.0114
Yes vs No		1.377	[1.075-1.765]
KRAS mutation	n = 356			0.0696
Yes vs No		1.256	[0.982-1.606]
BRAF mutation	n = 294			< 0.0001
Yes vs No		2.276	[1.511-3.429]
CEA	n = 366			< 0.0001
> 200 vs ≤ 200		1.654	[1.290-2.120]
LDH	n = 329			< 0.0001
> 254 vs ≤ 254		2.022	[1.574-2.596]
Leukocytes > 10000	n = 361			0.0016
Yes vs No		1.506	[1.168-1.941]
Alkaline phosphatase > 300	n = 335			< 0.0001
Yes vs No		2.272	[1.713-3.014]
PTR	n = 466			< 0.0001
Yes vs No		0.313	[0.250-0.392]
Oxaliplatin	n = 466			< 0.0001
Yes vs No		0.361	[0.248-0.524]
Irinotecan	n = 465			0.112
Yes vs No		0.807	[0.619-1.051]
5 FU or Capecitabine	n = 466			0.2869
Yes vs No		0.539	[0.173-1.682]
Bevacizumab	n = 463			0.0117
Yes vs No		0.750	[0.599-0.938]
EGFR inhibitors	n = 464			0.0129
Yes vs No		0.769	[0.625-0.946]
1rst line chemotherapy regimen	n = 462			0.0080
Bi-chemotherapy vs Mono-chemotherapy		0.682	[0.496-0.937]
Tri-chemotherapy vs Mono-chemotherapy		0.543	[0.368-0.799]
Lung or liver surgery or radio-frequency	n = 463			< 0.0001
Yes vs No		0.302	[0.235-0.388]

HR: Hazard ratio; CI: Carcinoembryonic antigen; CEA: Carcinoembryonic antigen; LDH: Lactate dehydrogenase; PTR: Primary tumor resection; 5 FU: 5 fluorouracil; EGFR: Epidermal growth factor.