Integrating TYMS, KRAS and BRAF testing in patients with metastatic colorectal cancer

Table 1 Thymidylate synthase polymorphisms’ groups per untranslated region

	Low expression	Medium expression	High expression
TYMS 3’UTR	del/del	ins/del	ins/ins
		del/LOH	ins/LOH
TYMS 5’UTR	2RG	2RG/3RG	3RG
	2RG/3RC	2RG/3RG	3RG/3RC
	3RC	2RG/3RCLOH	2RGLOH/3RG
		2RG/3RGLOH
		2RGLOH/3RC

LOH: Loss of heterozygosity; UTR: Untranslated region.

Table 2 Clinicopathologic data for patients with metastatic colorectal cancer n (%)

Clinicopathologic data	Relapses	De novo metastatic	Total
	48 (53.9)	41 (46.1)	89 (100)
Age	65 (40-84.1)	64 (27-86)	65 (27-86)
Male	34 (70.8)	23 (56.1)	57 (64.8)
Primary site
Colon	20 (41.7)	26 (63.4)	46 (51.7)
Rectum	28 (58.3)	15 (36.6)	43 (48.3)
Histological grade
I + II	27 (56.3)	28 (68.3)	55 (61.8)
III + IV	21 (43.7)	13 (31.7)	34 (38.2)
KRAS mutation	22 (45.8)	18 (43.9)	40 (44.9)
BRAF V600E mut	2 (4.2)	3 (7.3)	5 (5.6)
TYMS LOH	15 (31.3)	11 (26.8)	26 (29.2)
Fluoropyrimidine-based CT
Monotherapy or with	5 (10.4)	5 (12.2)	10 (11.2)
Irinotecan	18 (37.5)	10 (24.4)	28 (31.4)
Oxaliplatin	22 (45.8)	22 (53.7)	44 (49.4)
Oxaliplatin and irinotecan	3 (6.3)	3 (7.3)	6 (6.7)
Bevacizumab	31 (64.6)	30 (73.2)	61 (68.5)
No chemotherapy	0 (0.0)	1 (2.4)	1 (1.1)
Overall survival
Deaths	30 (62.5)	33 (80.5)	63 (70.8)
Time1 in mo	21.4 (12.2-30.6)	18.2 (14.3-22.0)	19.8 (15.8-23.9)
Progression-free survival
Events	44 (91.7)	41 (100.0)	85 (95.5)
Time1 in mo	10.8 (9.0-12.5)	9.9 (7.0-12.8)	10.6 (8.8-12.5)
Follow-up in mo	14.2 (0-72.5)	17.0 (0.8-119.8)	14.8 (0-119.8)

Data are presented as n (%) or median (range) or

¹(95%CI). CT: Chemotherapy; LOH: Loss of heterozygosity.

Table 3 Association between thymidylate synthase polymorphisms and patient characteristics

Polymorphism	Characteristic	RR (95%CI)	P value
2R	Age < 65-years-old	1.708 (1.158-2.520)	0.090
2RG/3RG	Grade 1-2	1.449 (1.077-1.948)	0.044
2RG/3RC	Female	1.943 (1.152-3.275)	0.036
ins/ins	KRAS G12D	3.563 (1.163-10.912)	0.045
3RG/3RC	KRAS wild-type	1.753 (1.156-2.657)	0.031

Table 4 Risk groups of thymidylate synthase polymorphisms

Group	Relapsed	De novo metastatic	Total
TYMS 5’UTR
Low expression
2RG	2 (4.2)	6 (14.6)	8 (9.0)
2RG/3RC	8 (16.7)	3 (7.3)	11 (12.4)
3RC	6 (12.5)	5 (12.2)	11 (12.4)
Medium expression
2RG/3RG	4 (8.3)	4 (9.8)	8 (9)
2RG/3RCLOH	7 (14.6)	3 (7.3)	10 (11.2)
2RG/3RGLOH	3 (6.3)	2 (4.9)	5 (5.6)
2RGLOH/3RC	1 (2.1)	2 (4.9)	3 (3.4)
High expression
3RG	4 (8.3)	4 (9.8)	8 (9.0)
3RG/3RC	9 (18.8)	8 (19.5)	17 (19.1)
2RGLOH/3RG	4 (8.3)	4 (9.8)	8 (9.0)
TYMS 3’UTR
Low expression
del/del	6 (12.5)	7 (17.1)	13 (14.6)
Medium expression
ins/del	19 (39.6)	10 (24.4)	29 (32.6)
del/LOH	1 (2.1)	3 (7.3)	4 (4.5)
High expression
ins/ins	8 (16.7)	13 (31.7)	21 (23.6)
ins/LOH	14 (29.2)	8 (19.5)	22 (24.7)

LOH: Loss of heterozygosity; UTR: Untranslated region.

Table 5 Univariate Cox regression analysis for clinicopathological features and genotype

Variable	PFS			OS
	HR	95%CI	P value	HR	95%CI	P value
KRAS mutated	1.390	0.895-2.164	0.142	1.669	0.996-2.797	0.052
BRAF V600E	0.884	0.356-2.196	0.791	1.514	0.545-4.207	0.426
LOH	1.013	0.632-1.624	0.957	1.020	0.592-1.758	0.944
TYMS 5’UTR			0.561			0.845
2R	1.000			1.000
2R/3R	1.243	0.616-2.508	0.543	1.276	0.556-2.928	0.565
3R	0.974	0.474-2.003	0.944	1.239	0.535-2.870	0.616
TYMS 5’UTR			0.887			0.486
2RG	1.000			1.000
2RG/3RC	1.151	0.535-2.475	0.720	0.978	0.388-2.468	0.963
2RG/3RG	1.351	0.625-2.921	0.444	1.688	0.689-4.132	0.252
3RC	1.038	0.428-2.517	0.935	0.876	0.293-2.620	0.813
3RG/3RC	0.883	0.391-1.995	0.764	1.648	0.660-4.113	0.284
3RG	1.107	0.433-2.832	0.832	1.054	0.348-3.189	0.926
TYMS 5’UTR			0.726			0.562
2R	1.000			1.000
2RG/3RC	1.864	0.738-4.713	0.188	1.678	0.546-5.160	0.366
2RG/3RCLOH	0.783	0.300-2.044	0.617	1.044	0.328-3.323	0.942
2RG/3RG	1.058	0.372-3.014	0.916	1.869	0.537-6.504	0.325
2RG/3RGLOH	1.936	0.630-5.948	0.248	3.875	1.019-14.740	0.047
2RGLOH/3RC	1.155	0.301-4.441	0.834	1.091	0.126-9.412	0.937
2RGLOH/3RG	1.656	0.617-4.442	0.317	1.745	0.546-5.576	0.348
3RC	1.096	0.428-2.806	0.848	1.070	0.325-3.521	0.912
3RG	1.163	0.432-3.134	0.765	1.281	0.385-4.270	0.687
3RG/3RC	1.001	0.413-2.426	0.998	2.144	0.758-6.064	0.151
TYMS 5’UTR groups			0.812			0.489
Low expression	1.063	0.633-1.784	0.818	0.696	0.384-1.261	0.232
Medium expression	0.888	0.518-1.523	0.667	0.851	0.460-1.572	0.606
High expression	1.000			1.000
TYMS 3’UTR			0.295			0.340
del/del	0.602	0.305-1.190	0.144	0.563	0.259-1.224	0.147
ins/del	0.764	0.475-1.228	0.267	0.910	0.522-1.587	0.739
ins/ins	1.000			1.000
TYMS 3’UTR			0.067		1	0.095
del/del	0.421	0.194-0.912	0.028	0.311	0.125-0.772	0.012
del/LOH	0.784	0.263-2.334	0.662	0.773	0.175-3.417	0.734
ins/del	0.438	0.240-0.802	0.007	0.459	0.230-0.918	0.028
ins/LOH	0.516	0.274-0.973	0.041	0.488	0.233-1.020	0.057
ins/ins	1.000			1.000
TYMS 3’UTR groups			0.225			0.187
Low expression	0.639	0.323-1.263	0.198	0.503	0.230-1.102	0.086
Medium expression	0.435	0.435-1.118	0.135	0.738	0.426-1.279	0.279
High expression	1.000			1.000

CT: Chemotherapy; LOH: Loss of heterozygosity; OS: Overall survival; PFS: Progression-free survival; UTR: Untranslated region.

Table 6 Multivariate Cox regression analysis

	PFS			OS
	HR	95%CI	P value	HR	95%CI	P value
KRAS mutated	1.600	1.011-2.531	0.045
LOH	1.674	0.912-3.071	0.096
Fluoropyrimidine-based CT
With irinotecan	0.600	0.372-0.969	0.037	0.352	0.164-0.757	0.007
Without irinotecan	1.000			1.000
With oxaliplatin				1.000
Without oxaliplatin				2.702	1.273-5.738	0.010
TYMS 3’UTR groups			0.043			0.027
Low expression	0.432	0.198-0.946	0.036	0.366	0.162-0.827	0.016
Medium expression	0.513	0.287-0.919	0.025	0.559	0.309-1.013	0.055
High expression	1.000			1.000
Sex
Males				1.580	0.916-2.724	0.100

CT: Chemotherapy; LOH: Loss of heterozygosity; OS: Overall survival; PFS: Progression-free survival; UTR: Untranslated region.