Table 1.

Relation Between Methylenetetrahydrofolate Reductase (MTHFR) C677T Genotype and Colorectal Cancer: General Characteristics of Studies Included in a Meta-Analysis^a and a Pooled Analysis

Authors (Ref. No.)	Year of Publication	No. of Cases	No. of Controls	Country	Ethnic Group(s) and %	Source of Controls	CT vs. CC		TT vs. CC
							OR	95% CI	OR	95% CI
North and South Asian Countries
Park et al. (72)	1999	200	460	South Korea	Korean, 100	Healthy persons	0.94	0.65, 1.36	0.81	0.48, 1.38
Yin et al. (69)	2004	685	778	Japan	Japanese, 100	Hospital patients	0.93	0.74, 1.16	0.66	0.48, 0.91
Kim et al. (33)b	2004	243	225	South Korea	Korean, 100	Hospital patients	1.08	0.73, 1.61	1.02	0.58, 1.80
Jiang et al. (71)b	2005	126	343	China	Chinese, 100	Healthy persons	1.08	0.70, 1.69	0.64	0.33, 1.22
Matsuo et al. (67)b	2005	257	771	Japan	Japanese, 100	Hospital patients	0.89	0.66, 1.21	0.73	0.48, 1.13
Otani et al. (68)	2005	121	245	Japan	Japanese, 100	Hospital patients	0.69	0.39, 1.19	0.70	0.37, 1.33
Wang et al. (70)	2006	302	291	India	Indian, 100	Hospital patients	1.19	0.74, 1.91	NA	NA
Chang et al. (73)	2007	195	195	Taiwan	Taiwanese, 100	Hospital patients	1.07	0.70, 1.63	1.62	0.81, 3.26
Matsuo et al. (74)	2002	142	241	Japan	Japanese, 100	Hospital patients	1.36	0.84, 2.18	1.27	0.66, 2.44
European Countries
Ryan et al. (78)	2001	136	848	Ireland	White, 100	Healthy persons	2.01	1.36, 2.96	1.51	0.80, 2.86
Sachse et al. (79)b	2002	490	592	United Kingdom	White, 100	Healthy persons	0.83	0.65, 1.07	1.23	0.80, 1.89
Plaschke et al. (80)b	2003	287	346	Germany	White, 100	Healthy persons	0.85	0.61, 1.18	1.00	0.60, 1.68
Toffoli et al. (81)b	2003	276	279	Italy	White, 100	Healthy persons	0.92	0.63, 1.35	0.61	0.36, 1.01
Pufulete et al. (87)b	2003	28	76	United Kingdom	White, 100	Hospital patients	0.53	0.19, 1.52	2.56	0.72, 9.13
Ulvik et al. (82)	2004	2,178	2,178	Norway	White, 100	Healthy persons	1.00	0.89, 1.14	0.73	0.59, 0.92
Landi et al. (88)b	2005	350	309	Spain	White, 100	Hospital patients	0.97	0.69, 1.36	0.89	0.58, 1.38
Van Guelpen et al. (75)	2006	254	415	Sweden	White, 100	Healthy persons	0.91	0.65, 1.28	0.49	0.25, 0.97
Zeybek et al. (83)	2007	86	144	Turkey	White, 100	Hospital patients	1.48	0.74, 2.94	1.66	0.59, 4.69
Sharp et al. (84)b	2008	275	370	Scotland	White, 100	Healthy persons	0.91	0.65, 1.27	0.71	0.41, 1.23
United States
Chen et al. (32)	1996	144	627	United States	White, 100	Healthy persons	1.02	0.69, 1.49	0.65	0.34, 1.23
Ma et al. (38)	1997	202	326	United States	White, 100	Healthy persons	1.10	0.76, 1.60	0.58	0.32, 1.06
Slattery et al. (28)	2000	1,467	1,821	United States	Black, 4.2; Hispanic, 4.4; white, 91.4	Hospital patients	1.02	0.88, 1.18	0.83	0.65, 1.05
Keku et al. (29)b	2002	643	1,048	United States	Black, 39; white, 61	Healthy persons	1.00	0.80, 1.26	0.73	0.45, 1.18
Le Marchand et al. (39)b	2002	548	656	United States	Japanese, 58.8; white, 27.2; Hawaiian, 14.0	Healthy persons	0.90	0.71, 1.15	0.71	0.50, 1.01
Le Marchand et al. (27)b	2005	822	2,021	United States	Japanese-American, 26; white, 23; Latino American, 22; black, 16; Native American, 7; other, 6	Healthy persons	1.08	0.91, 1.28	0.85	0.65, 1.12
Koushik et al. (85)	2006	349	794	United States	White, 100	Healthy persons	0.95	0.72, 1.24	0.73	0.48, 1.09
Murtaugh et al. (66)	2007	751	979	United States	White, 84; Hispanic, 6; black, 4; other, 5	Healthy persons	0.99	0.65, 1.27	0.97	0.71, 1.33
Other Countries
Shannon et al. (86)	2002	501	1,207	Australia	White, 100	Healthy persons	0.75	0.60, 0.94	1.03	0.72, 1.47
Lima et al. (65)b	2007	102	300	Brazil	White, 88.2; black, 9.8; unclassified, 2.0	Hospital patients	1.26	0.78, 2.05	1.74	0.86, 3.55

Abbreviations: CI, confidence interval; NA, not available; OR, odds ratio.

^aOne study published in Hungarian (58) could not be evaluated in the meta-analysis.

^bStudy was also included in the pooled analysis (n = 13 studies).