Prognostic significance of primary tumor localization in stage II and III colon cancer

Table 1 Comparison of clinical and pathological data according to tumor localization

		All patients		RCC		LCC
		(n = 942)		(n = 456)		(n = 486)
		n	%	n	%	n	%	P
Age (yr)	< 65	636	67.5	304	66.7	332	68.3	0.590
	≥ 65	306	32.5	152	33.3	154	31.7
Gender	Male	511	54.2	250	54.8	261	53.7	0.730
	Female	431	45.8	206	45.2	225	46.3
Family history	No	916	97.2	439	96.3	477	98.1	0.790
	Yes	26	2.8	17	3.7	9	1.9
Smoking status	No	592	62.8	277	60.7	315	64.8	0.192
	Yes	350	37.2	179	39.3	171	35.2
Alcohol use status	No	893	94.8	434	95.2	459	94.4	0.614
	Yes	49	5.2	22	4.8	27	5.6
Mode of surgery	Elective	791	84	400	87.7	391	80.5	0.002
	Emergent	151	16	56	12.3	95	19.5
DM	No	845	89.7	407	89.3	438	90.1	0.527
	Yes	93	9.9	48	10.5	45	9.3
HT	No	717	76.1	344	75.4	373	76.7	0.329
	Yes	223	23.7	112	24.6	111	22.8
Histology	Adenocarcinoma	779	82.7	356	78.1	423	87	< 0.001
	Mucinous adenocarcinoma	163	17.3	100	21.9	63	13
Tumor grade	Well and moderately	879	93.3	420	92.1	459	94.4	0.151
	Poorly	63	6.7	36	7.9	27	5.6
Tumor stage	II	567	60.2	271	59.4	296	60.9	0.644
	III	375	39.8	185	40.6	190	39.1
pT stage	T1-2	133	14.1	57	12.5	76	15.6	0.267
	T3	752	79.8	374	82	378	77.8
	T4	57	6.1	25	5.5	32	6.6
The number of removed lymph nodes	< 12	296	31.4	102	22.4	194	39.9	< 0.001
	≥ 12	646	68.6	354	77.6	292	60.1
pN	N0	567	60.2	269	59	298	61.3	0.589
	N1	273	29	133	29.2	140	28.8
	N2	102	10.8	54	11.8	48	9.9
PNI	Negative	728	78.3	354	78.5	374	78.1	0.879
	Positive	202	21.7	97	21.5	105	21.9
LVI	Negative	629	67.8	303	67.3	326	68.2	0.777
	Positive	299	32.2	147	32.7	152	31.8
Surgical margin	Negative	928	98.5	449	98.5	479	98.6	0.096
	Positive	8	0.8	6	1.3	2	0.4
Adjuvant treatment	No	208	22.1	94	20.6	114	23.5	0.293
	Yes	734	77.9	362	79.4	372	76.5
Adjuvant treatment regimen	5-FU-based	493	67.2	243	67.1	250	67.2	0.978
	Oxaliplatin-based	241	32.8	119	32.9	122	32.8
Completion rate of adjuvant treatment		695	94.7	344	95	351	94.4	0.685
Tumor recurrence	No	804	85.4	389	85.3	415	85.4	0.971
	Yes	138	14.6	67	14.7	71	14.6
	Locoregional recurrence	40	29	21	31.3	19	26.8	0.553
	Systemic recurrence	98	71	46	68.7	52	73.2
Metastasectomy		48	34.8	24	35.8	24	33.8	0.804
Status	Exitus	95	9.1	51	11.2	44	9.1	0.278
	Alive	847	90.9	405	88.8	486	90.9
		Median	Min-Max	Median	Min-Max	Median	Min-Max
Age (yr)		58	19-94	57	19-89	58	21-94	0.141
Follow-up (mo)		90	1-252	90	1-252	90	5-235
		mean	SD	mean	SD	mean	SD
Number of removed lymph nodes		17.57	10.843	19.78	11.059	15.5	10.223	< 0.001
Number of metastatic lymph nodes		1.46	4.068	1.41	2.86	1.5	4.944	0.743

DM: Diabetes mellitus; HT: Hypertension; Max: Maximum; Min: Minimum; LCC: Left colon cancer; LVI: Lymphovascular invasion; n: Number of patients; pN: Pathological lymph node stage; PNI: Perineural invasion; pT: Pathological tumor stage; RCC: Right colon cancer.

Table 2 Disease free survival and overall survival rates (%) at 12, 36, 60, 90, 120 and 180 mo according to tumor localization

	All patients (%)	RCC (%)		LCC (%)
DFS (mo)		Stage II	Stage III	Stage II	Stage III
12	97.9	98.9	96.2	98.0	96.8
36	89.8	93.9	83.6	94.5	81.9
60	87.0	93.1	79.4	91.8	78.2
90	84.9	92.6	75.9	91.3	76.7
120	84.4	92.0	75.0	90.5	74.4
180	82.7	90.3	73.2	90.5	72.2
OS (mo)
12	99.8	99.3	100.0	99.7	100.0
36	96.7	96.2	95.5	99.3	94.4
60	92.4	94.5	86.2	97.0	87.9
90	89.5	94.0	82.5	94.4	86.4
120	87.6	92.7	78.9	93.8	82.9
180	86.6	92.7	78.9	92.1	82.9

LCC: Left colon cancer; OS: Overall survival; RCC: Right colon cancer; DFS: Disease free survival.

Table 3 Factors affecting disease free survival

		Univariate analysis						Multivariate analysis
		HR		95%CI		P		HR		95%CI		P
Age (yr)	< 65	1						1
	≥ 65	1.779	1.268		2.496		0.001	1.88	1.305		2.708		0.001
Gender	Male	1
	Female	0.96	0.686		1.343		0.812
Family history	No	1
	Yes	1.195	0.489		2.919		0.696
Smoking status	No	1
	Yes	0.908	0.641		1.287		0.587
Alcohol using status	No	1
	Yes	0.372	0.118		1.167		0.09
Mode of surgery	Elective	1						1
	Emergent	1.796	1.22		2.646		0.003	1.718	1.131		2.611		0.011
DM	No	1
	Yes	0.973	0.549		1.724		0.925
HT	No	1
	Yes	1.541	0.967		2.224		0.067
Histology	Adenocarcinoma	1
	Mucinous adenocarcinoma	1.207	0.793		1.839		0.38
Tumor grade	Well and moderately	1
	Poorly	1.574	0.889		2.787		0.119
Tumor location	RCC	1
	LCC	0.997	0.714		1.392		0.984
Tumor stage	II	1						1
	III	2.99	2.109		4.238		< 0.001	2.281	1.485		3.505		< 0.001
pT stage	T1 + 2	1					< 0.001
	T2	1.912	0.999		3.662		0.05
	T4	9.308	4.478		19.348		< 0.001
Number of removed lymph nodes	≥ 12	1						1
	< 12	2.166	1.421		3.301		< 0.001	1.751	1.13		2.712		0.012
pN	N0	1					< 0.001
	N1	2.779	1.908		4.047		< 0.001
	N2	3.56	2.237		5.664		< 0.001
PNI	Negative	1						1
	Positive	3.953	2.801		5.578		< 0.001	2.277	1.549		3.347		< 0.001
LVI	Negative	1						1
	Positive	3.372	2.382		4.774		< 0.001	1.825	1.221		2.728		0.003
Surgical margin	Negative	1
	Positive	3.884	1.436		10.505		0.008
Adjuvant treatment	No	1						1
	Yes	0.591	0.346		0.954		0.041	0.514	0.323		0.82		0.005

DM: Diabetes mellitus; HT: Hypertension; Max: Maximum; Min: Minimum; LCC: Left colon cancer; LVI: Lymphovascular invasion; pN: Pathological lymph node stage; PNI: Perineural invasion; pT: Pathological tumor stage; RCC: Right colon cancer.

Table 4 Factors affecting overall survival

		Univariate analysis						Multivariate analysis
		HR	95%CI				P	HR		95%CI			P
Age (yr)	< 65	1						1
	≥ 65	4.136		2.731	6.263	< 0.001		4.049	2.578		6.358	< 0.001
Gender	Male	1
	Female	0.951		0.636	1.423	0.808
Family history	No	1
	Yes	0.306		0.043	2.196	0.239
Smoking status	No	1
	Yes	0.815		0.533	1.247	0.346
Alcohol using status	No	1
	Yes	0.348		0.086	1.411	0.139
Mode of surgery	Elective	1
	Emergent	1.342		0.812	2.219	0.252
DM	No	1
	Yes	1.683		0.953	2.972	0.073
HT	No	1
	Yes	3.067		2.035	4.623	< 0.001
Histology	Adenocarcinoma	1
	Mucinous adenocarcinoma	1.213		0.733	2.006	0.452
Tumor grade	Well and moderately	1
	Poorly	1.036		0.453	2.369	0.933
Tumor location	RCC	1
	LCC	0.807		0.539	1.208	0.297
Tumor stage	II	1						1
	III	2.363		1.57	3.557	< 0.001		1.723	1.037		2.863	0.036
pT stage	T1 + 2	1				< 0.001
	T2	4.836		1.526	15.326	0.007
	T4	21.34		6.162	73.897	< 0.001
Number of removed lymph nodes	≥ 12	1
	< 12	1.402		0.897	2.192	0.138
pN	N0	1				< 0.001
	N1	2.122		1.353	3.327	0.001
	N2	3.015		1.742	5.219	< 0.001
PNI	Negative	1						1
	Positive	3.653		2.4	5.562	< 0.001		2.198	1.374		3.517	0.001
LVI	Negative	1						1
	Positive	3.735		2.445	5.707	< 0.001		2.523	1.543		4.127	< 0.001
Surgical margin	Negative	1
	Positive	2.57		0.633	10.435	0.187
Adjuvant treatment	No	1						1
	Yes	0.587		0.379	0.91	0.017		0.517	0.311		0.86	0.011

DM: Diabetes mellitus; HT: Hypertension; LCC: Left colon cancer; LVI: Lymphovascular invasion; pN: Pathological lymph node stage; PNI: Perineural invasion; pT: Pathological tumor stage; RCC: Right colon cancer.