Emerging roles of the ribonucleotide reductase M2 in colorectal cancer and ultraviolet-induced DNA damage repair

Table 1 Relationship between ribonucleotide reductase M2 gene expression in tumor and pathological parameters in patients n (%)

Clinical or pathologic feature	Total (n)	RRM2+	P value
All cases	56	38 (67.9)
Gender			0.0908
Male	33	20 (60.6)
Female	23	18 (78.3)
Age (yr)			0.2094
≤ 64	29	19 (65.5)
≥ 65	27	19 (70.4)
Tumor stage (invasion depth)			0.0015
Tis/T1	3	0
T2	16	6 (37.5)
T3	32	24 (75.0)
T4	5	1 (20.0)
Tumor size (cm2, average = 17.3)			0.0677
≤ 17	31	20
> 17	25	11
Lymph node metastasis (N)			0.2281
Absent	25	14 (56.0)
1-3	21	16 (76.2)
≥ 4	10	8 (80.0)
Classification (differentiation)			0.0051
High-grade	5	1 (20.0)
Mid-grade	45	35 (77.8)
Low-grade	6	2 (33.3)

RRM2: Ribonucleotide reductase M2.

Table 2 Relationship between ribonucleotide reductase M2 overexpression with invasion depth and poor differentiation

Pathologic feature	Total (n)	RRM2-		RRM2+		DF	P value
		Score 0	Score 1	Score 2	Score 3
Tumor stage (invasion depth)						1	< 0.0001
Tis/T1	17	12	4	1	0
T2	26	1	6	16	3
T3	21	0	2	8	11
T4	14	0	2	5	7
Classification (differentiation)						1	< 0.0001
High	20	9	9	2	0
Mid	39	4	3	20	12
Low	19	0	2	8	9

RRM2: Ribonucleotide reductase M2; DF: Degrees of freedom.