Association between clinicopathological features and survival in patients with primary and paired metastatic colorectal cancer and KRAS mutation

Figures & data

Figure 1 (A) Internal control gene in HEX channel. (B) KRAS gene Wild-type in FAM channel. (C) KRAS gene mutant-type in FAM channel. (D) KRAS gene double mutant-type in FAM channel.

Figure 2 KRAS gene single mutation rate of codons 12 and 13 in primary and metastatic CRC.

Abbreviation: CRC, colorectal cancer.

Table 1 KRAS gene mutation location in primary tumors and metastases

KRAS mutation site	N	Primary CRC				N	Metastatic CRC
		Left	Right	Transverse	Rectum		LN	Liver/lung
G12C	9	3	2	0	4	3	1	2
G12S	5	1	2	0	2	1	0	1
G12R	1	1	0	0	0	0	0	0
G12V	24	9	5	1	9	7	4	3
G12D	38	13	8	1	16	11	7	4
G12A	2	1	0	0	1	1	1	0
G13D	15	7	5	0	3	0	0	0
G12R/G12D	2	0	1	0	1	0	0	0
G12S/G12A	1	0	0	0	1	0	0	0
G12V/G12A	1	1	0	0	0	0	0	0

Notes: The KRAS gene mutation rate was 42.6% (98/230) in 230 primary CRC tumors, and G12D mutations were most common, accounting for 16.5% of all samples (38/230) and 38.8% (38/98) of all mutations. Twenty-three of 72 metastatic CRC samples harbored KRAS mutations, corresponding to a mutation rate of 31.9% (23/72); G12D mutations were most common, accounting for 47.8% (11/23) of all mutations and 15.3% of all samples (11/72).

Abbreviations: CRC, colorectal cancer; LN, lymph node.

Table 2 Analysis of the clinical and pathological characteristics of patients with primary tumors, and comparison of patients having only a primary lesion with those having paired metastatic lesions and association between CRC and codons 12 and 13

Parameters	KRAS status		P-value	LN involvement		P-value	Comparison with codons		P-value
	WT	Mut		Yes	No		12	13
Sex			0.779			0.800			0.718
Male	73	57		46	84		49	8
Female	58	42		37	63		35	7
Age (years)			0.626			0.248			0.929
≥65	90	65		50	105		55	10
<65	41	34		30	45		29	5
Ethnic			0.812			0.624			0.457
Han	101	75		62	114		62	13
Uyghur	30	24		21	33		22	2
Differentiation			0.626			0.755			0.004
High/moderate	90	65		57	98		60	5
Poor	41	34		26	49		24	10
Tumor infiltrating			0.029			<0.001			0.181
T1/T2	48	23		11	60		17	6
T3/T4	83	76		72	87		67	9
TNM stage			0.041			<0.001			0.017
I/II	85	51		18	118		39	12
III/IV	46	48		65	29		45	3
LN involvement			0.010						0.007
N0	93	54		0	147		41	13
N1/N2	38	45		83	0		43	2
Metastasis			0.900			<0.001			0.767
M0	121	91		6	141		78	13
M1	10	8		77	6		6	2
Localization			0.143			0.789			0.179
Colon	64	58		45	77		46	12
Rectum	67	41		38	70		38	3
Localization (colon)			0.156			0.513			0.516
Left	42	33		25	50		26	7
Right	15	22		15	22		16	6
Transverse	7	3		5	5		2	0

Abbreviations: CRC, colorectal cancer; LN, lymph node; TNM, tumor node metastasis; WT, wide-type; Mut, mutation.

Table 3 The relationship between gene status and the clinical and pathological features of CRC metastases stratified by KRAS status

Parameters	KRAS status		P-value
	WT	Mut
Sex			0.927
Male	25	12
Female	24	11
Ethnic			0.573
Han	33	17
Uyghur	16	6
Age (years)			0.035
<65	34	10
≥65	15	13
Differentiation			0.892
High/well	29	14
Poor	20	9
Tumor infiltrating			0.034
T1/T2	11	0
T3/T4	38	23
TNM stage			0.512
I/II	8	6
III/IV	41	17
LN involvement			0.822
N0	4	3
N1/N2	45	20
Metastasis			0.148
M0	47	19
M1	2	4
Localization			0.040
LN metastases	45	17
Liver/lung metastases	4	6

Abbreviations: CRC, colorectal cancer; WT, wide-type; Mut, mutation; TNM, tumor node metastasis; LN, lymph node.

Table 4 Comparison of KRAS gene status between primary CRC tumors and metastases of CRC

Primary	Metastases		P-value
	Mut, n (%)	WT, n (%)
Mut	23 (100.0)	13 (25.7)	<0.001
WT	0	36 (74.3)

Notes: Paired chi-squared test examining differences in the KRAS gene status between primary and metastatic tumors. Thirty-six primary tumors each harbored mutant and wild-type KRAS, whereas 23 and 49 metastases harbored mutant and wild-type KRAS, respectively. In 13 primary tumors harboring mutant KRAS, the paired metastases harbored wild-type KRAS. Significant differences are denoted by P<0.05.

Abbreviations: CRC, colorectal cancer; WT, wide-type; Mut, mutation.

Figure 3 The Kaplan-Meier survival curve for patients with the KRAS gene.

Notes: (A) Overall survival stratified by KRAS Mut and WT. (B) Disease-free survival stratified by KRAS Mut and WT. (C) Overall survival stratified by KRAS status and chemotherapy. (D) Disease-free survival stratified by KRAS status and chemotherapy. (E) Overall survival stratified by KRAS WT and cetuximab. (F) Disease-free survival stratified by KRAS WT and cetuximab.
Abbreviations: che, chemotherapy; cet, cetuximab; Mut, mutation; WT, wild-type.

Table 5 Univariate prognostic analysis of OS and DFS

Parameters	Overall survival		Disease-free survival
	HR (95% CI)	P-value	HR (95% CI)	P-value
Gender
Male vs female	1.289 (0.497–3.347)	0.601	1.579 (0.285–1.042)	0.066
Ethnicity
Han vs Uyghur	0.748 (0.228–2.450)	0.631	1.435 (0.906–2.274)	0.124
Age (years)
<65 vs ≥65	1.452 (0.557–3.787)	0.446	0.631 (0.339–1.173)	0.146
Differentiation
PD vs MD + WD	1.024 (0.482–2.2175)	0.951	0.724 (0.417–0.256)	0.251
Tumor infiltration
T1/T2 vs T3/T4	1.020 (0.353–2.950)	0.971	4.349 (1.531–12.353)	0.006
TNM stage
I/II vs III/IV	3.039 (0.848–10.896)	0.088	1.637 (0.776–3.455)	0.196
LN involvement
N0 vs N1/N2	0.308 (0.093–1.026)	0.055	0.808 (0.432–1.509)	0.503
Metastasis
M0 vs M1	0.856 (0.102–7.200)	0.886	1.241 (0.408–3.777)	0.704
Localization
Colon vs rectum	0.370 (0.145–0.943)	0.037	0.353 (0.187–0.666)	0.001
KRAS gene status
Mutant vs wild-type	1.413 (1.181–4.928)	0.004	1.845 (1.125–3.027)	0.010
Codons
12 vs 13	1.716 (0.506–5.820)	0.386	1.462 (0.612–3.494)	0.373

Abbreviations: OS, overall survival; DFS, disease-free survival; HR, hazard ratio; CI, confidence interval; PD, poor differentiation; MD, moderate differentiation; WD, well differentiated; TNM, tumor node metastasis; LN, lymph node.

Table 6 Logistic regression models to find out predictors of OS and DFS

Characteristic	OS		DFS
	OR (95% CI)	P-value	OR (95% CI)	P-value
G12C	1.182 (0.132–10.590)	0.881	0.949 (0.175–5.150)	0.952
G12S	1.181 (0.102–13.612)	0.894	2.807 (0.419–18.823)	0.288
G12R	0	0.999	0	0.999
G12V	6.049 (2.153–16.996)	0.001	4.517 (1.661–4.517)	0.003
G12D	4.853 (1.958–12.027)	0.001	4.530 (1.959–10.479)	<0.001
G12A	4.510 (0.489–41.591)	0.184	4.205 (0.384–46.037)	0.239
G13D	2.364 (0.568–9.839)	0.237	2.373 (0.711–7.917)	0.16

Abbreviations: OS, overall survival; DFS, disease-free survival; OR, odds ratio; CI, confidence interval.