One-carbon metabolism mediates the interconversion of folates for the synthesis of precursors used in DNA synthesis, repair, and methylation. Inadequate folate nutrition or compromised metabolism can disrupt these processes and facilitate carcinogenesis. In this study, we investigated associations of 39 candidate single nucleotide polymorphisms (SNP) in 9 one-carbon metabolism genes with risk of prostate cancer using 1,144 cases and 1,144 controls from the Cancer Prevention Study-II Nutrition Cohort. None of these SNPs were significantly associated with prostate cancer risk, either overall or in cases with advanced prostate cancer. Thus, our findings do not support the hypothesis that common genetic variation in one-carbon metabolism genes influences prostate cancer risk. (Cancer Epidemiol Biomarkers Prev 2008;17(12):3612–4)

Perturbation in one-carbon metabolism caused by inadequate folate nutrition or genetic variation in the enzymes in this pathway can compromise the synthesis of DNA precursors, disturb DNA repair and methylation, and facilitate carcinogenesis. Disruption of these basic processes could potentially influence tumor development in any tissue. However, the only cancer for which an association with altered one-carbon metabolism has been consistently found to date is colorectal cancer (1, 2). A number of studies have examined whether risk of prostate cancer, the most frequent cancer among men in the United States (3), is affected by changes in folate nutrition or metabolism. The results of studies of dietary folate (4-7), blood folate levels (8-11), and common genetic variants in methylenetetrahydrofolate reductase (MTHFR; refs. 12-16) have been mixed. In this study, we investigated the association of the genes MTHFR, methionine synthase (MTR), methionine synthase reductase (MTRR), cystathionine β-synthase (CBS), serine hydroxymethyltransferase (SHMT1), thymidine synthase (TYMS), dihydrofolate reductase (DHFR), methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase/formyltetrahydrofolate synthase (MTHFD1), and formyltetrahydrofolate dehydrogenase (FTHFD) with prostate cancer using cases and controls nested in the American Cancer Society Cancer Prevention II Nutrition Cohort.

Study Population

Prostate cancer cases and controls were participants in the Cancer Prevention II Nutrition Cohort, a prospective study of cancer incidence of ∼184,000 U.S. adults that begun in 1992. The recruitment and characteristics of this cohort have been described previously (17). Incident cases reported by response to follow-up questionnaires, which were sent to participants in 1997 and every 2 y afterwards, or by linkage with the National Death Index were verified through medical records or state cancer registries (17). Blood samples were collected from a subset of Nutrition Cohort participants (21,965 women and 17,411 men) between June 1998 and June 2001.

We identified 1,144 men with a blood sample who had been diagnosed with prostate cancer between 1992 and 2003 and had no previous history of cancer (except nonmelanoma skin cancer). An equal number of controls were matched to the cases on age (±6 mo), race/ethnicity, and date of blood collection (±6 mo) using risk set sampling (18). Among the cases, 272 men had advanced prostate cancer, defined as prostate cancer with Gleason score of ≥8, grades 3 to 4, or stage D at diagnosis, or who had prostate cancer as their underlying cause of death.

Single Nucleotide Polymorphism Selection and Genotyping

Single nucleotide polymorphisms (SNP) were selected from the dbSNP or Celera databases in October, 2004 if they (a) had a minor allele frequency in Caucasians (>5%), and (b) caused changes in the amino acid sequence, or (c) had been previously found to be associated with disease. For some genes for which only one SNP was identified using these criteria, one or two additional SNPs for which only frequency information was available were added. Seven additional tagging SNPs were selected for the FTHFD gene using early HapMap data (Release 16, 3/1/2005) to allow haplotype analysis of this gene.

All SNPs were genotyped using TaqMan at Applied Biosystems, Inc. The genotyping success rate was >96%, and the genotype distributions of the controls for all SNPs were in Hardy-Weinberg equilibrium (P > 0.01).

Statistical Analysis

The association with prostate cancer risk was evaluated using a per allele odds ratio determined using unconditional logistic regression in which a continuous variable for the number of minor alleles (0, 1, or 2) was entered into the regression model. All models were adjusted for age (single year categories), race (White, other), and date of blood draw (single year categories). Haplotypes for blocks defined through Haploview (19) were estimated using the expectation-maximization algorithm implemented in the TAGSNPS program (20).

Details of the 39 one-carbon metabolism SNPs studied are listed in Table 1. Based on the per-allele odds ratios and related P values shown in this table, which assume an additive genetic model, none of the SNPs were significantly associated with an altered risk of prostate cancer. Additionally, no significant association was seen when the analysis was restricted to advanced prostate cancer. To consider the possibility that some SNPs may act through a recessive model, we also assessed the association of the homozygous variant genotype with prostate cancer. Again, no statistically significant associations were found, either with all prostate cancer cases or with advanced prostate cancer cases.

Table 1.

Gene locations, resulting amino acid changes, minor allele frequencies, and associations with prostate cancer risk for the one-carbon metabolism gene SNPs investigated in this study

Gene/SNPLocationAA changeMinor alleleMinor allele frequency
OR (95% CI)*P†
CasesControls
MTHFR        
    rs2066470, T118C Exon 2 None T 210 (9.6) 207 (9.5) 1.01 (0.82-1.23) 0.94 
    rs1801133, C677T Exon 5 Val → Ala T 739 (33.6) 765 (34.6) 0.96 (0.85-1.09) 0.56 
    rs1801131, A1298C Exon 8 Ala → Glu C 728 (33.0) 743 (33.5) 0.97 (0.86-1.10) 0.64 
    rs2274976 Exon 12 Gln → Arg A 95 (4.3) 120 (5.4) 0.78 (0.59-1.03) 0.08 
MTR        
    rs1806505 Intron 13 N/A‡ T 877 (39.6) 856 (38.6) 1.05 (0.93-1.18) 0.44 
    rs1805087, A2756G Exon 26 Asp → Gly G 435 (19.9) 430 (19.5) 1.03 (0.89-1.20) 0.69 
    rs1050993 3′ UTR N/A‡ A 837 (37.8) 880 (39.6) 0.92 (0.82-1.04) 0.18 
MTRR        
    rs1801394, A66G Exon 2 Met → Ile A 1,021 (46.1) 1,005 (45.5) 1.02 (0.91-1.15) 0.70 
    rs1532268 Exon 5 Leu → Ser T 815 (36.9) 798 (36.0) 1.04 (0.92-1.17) 0.54 
    rs162036 Exon 7 Lys → Arg G 273 (12.4) 251 (11.3) 1.11 (0.92-1.33) 0.28 
    rs10380 Exon 14 Tyr → His T 231 (10.4) 221 (10.0) 1.05 (0.86-1.27) 0.65 
CBS        
    rs234706, Y233Y Exon 8 None A 745 (33.7) 780 (35.1) 0.94 (0.83-1.06) 0.32 
    rs1801181, C1261T Exon 12 None T 774 (36.9) 739 (35.1) 1.08 (0.95-1.23) 0.23 
SHMT1        
    rs64333 5′ UTR N/A‡ A 677 (30.7) 636 (28.7) 1.10 (0.97-1.25) 0.15 
    rs2273028 Intron 7 N/A‡ T 725 (32.9) 691 (31.2) 1.08 (0.96-1.23) 0.22 
    rs1979277, C1420T Exon 12 Leu → Phe A 702 (31.8) 675 (30.6) 1.06 (0.93-1.20) 0.39 
TYMS        
    rs502396 Intron 1 N/A‡ C 1,078 (49.0) 1,057 (47.9) 1.04 (0.93-1.17) 0.50 
    rs1001761 Intron 2 N/A‡ T 1,067 (49.3) 1,016 (47.0) 1.09 (0.97-1.23) 0.15 
    rs699517 3′ UTR N/A‡ T 733 (33.2) 693 (31.2) 1.09 (0.96-1.23) 0.20 
DHFR        
    rs836821 Intron 2 N/A‡ T 552 (25.0) 594 (26.8) 0.91 (0.79-1.04) 0.16 
    rs1677693 Intron 3 N/A‡ A 550 (25.0) 581 (26.5) 0.93 (0.81-1.06) 0.26 
    rs1643638 Intron 4 N/A‡ C 547 (24.9) 589 (26.6) 0.92 (0.80-1.05) 0.20 
MTHFD1        
    rs1076991 5′ UTR N/A‡ G 1,017 (46.1) 1,022 (46.5) 0.98 (0.87-1.11) 0.78 
    rs1950902, R134K Exon 6 Arg → Lys T 413 (18.7) 411 (18.5) 1.01 (0.87-1.17) 0.91 
    rs2236225, R653Q Exon 20 Arg → Gln T 1,039 (47.3) 1,006 (46.0) 1.05 (0.93-1.19) 0.39 
    rs2236224 Intron 21 N/A‡ T 919 (41.5) 911 (41.0) 1.02 (0.90-1.15) 0.78 
FTHFD (ALDH1L1)        
    rs7617733 Intron 1 N/A‡ A 379 (17.1) 360 (16.2) 1.06 (0.91-1.24) 0.46 
    rs4646701 Intron 2 N/A‡ A 854 (38.7) 868 (39.4) 0.98 (0.86-1.10) 0.69 
    rs1823213 Intron 2 N/A‡ A 737 (33.4) 765 (34.5) 0.96 (0.85-1.09) 0.50 
    rs2276731 Intron 4 N/A‡ C 411 (18.7) 418 (18.8) 0.99 (0.85-1.15) 0.90 
    rs10934751 Intron 8 N/A‡ G 1,066 (48.1) 1,066 (48.0) 1.00 (0.89-1.13) 0.94 
    rs1965848 Intron 8 N/A‡ T 896 (40.7) 906 (41.1) 0.98 (0.87-1.11) 0.80 
    rs2886059 Exon 9 Val → Phe T 357 (16.1) 352 (15.9) 1.01 (0.86-1.19) 0.88 
    rs11923466 Intron 9 N/A‡ C 920 (42.1) 911 (41.3) 1.03 (0.91-1.16) 0.64 
    rs2002287 Intron 13 N/A‡ C 766 (34.6) 771 (34.8) 0.99 (0.88-1.12) 0.88 
    rs2365004 Intron 14 N/A‡ A 768 (34.6) 773 (34.9) 0.99 (0.87-1.12) 0.85 
    rs6774437 Intron 16 N/A‡ A 1,065 (48.0) 1,051 (47.3) 0.97 (0.86-1.09) 0.65 
    rs2290053 Intron 18 N/A‡ A 1,085 (49.2) 1,099 (49.9) 1.03 (0.91-1.16) 0.63 
    rs1127717, A2380C Exon 21 Asp → Gly G 490 (22.2) 452 (20.4) 1.12 (0.97-1.29) 0.13 
Gene/SNPLocationAA changeMinor alleleMinor allele frequency
OR (95% CI)*P†
CasesControls
MTHFR        
    rs2066470, T118C Exon 2 None T 210 (9.6) 207 (9.5) 1.01 (0.82-1.23) 0.94 
    rs1801133, C677T Exon 5 Val → Ala T 739 (33.6) 765 (34.6) 0.96 (0.85-1.09) 0.56 
    rs1801131, A1298C Exon 8 Ala → Glu C 728 (33.0) 743 (33.5) 0.97 (0.86-1.10) 0.64 
    rs2274976 Exon 12 Gln → Arg A 95 (4.3) 120 (5.4) 0.78 (0.59-1.03) 0.08 
MTR        
    rs1806505 Intron 13 N/A‡ T 877 (39.6) 856 (38.6) 1.05 (0.93-1.18) 0.44 
    rs1805087, A2756G Exon 26 Asp → Gly G 435 (19.9) 430 (19.5) 1.03 (0.89-1.20) 0.69 
    rs1050993 3′ UTR N/A‡ A 837 (37.8) 880 (39.6) 0.92 (0.82-1.04) 0.18 
MTRR        
    rs1801394, A66G Exon 2 Met → Ile A 1,021 (46.1) 1,005 (45.5) 1.02 (0.91-1.15) 0.70 
    rs1532268 Exon 5 Leu → Ser T 815 (36.9) 798 (36.0) 1.04 (0.92-1.17) 0.54 
    rs162036 Exon 7 Lys → Arg G 273 (12.4) 251 (11.3) 1.11 (0.92-1.33) 0.28 
    rs10380 Exon 14 Tyr → His T 231 (10.4) 221 (10.0) 1.05 (0.86-1.27) 0.65 
CBS        
    rs234706, Y233Y Exon 8 None A 745 (33.7) 780 (35.1) 0.94 (0.83-1.06) 0.32 
    rs1801181, C1261T Exon 12 None T 774 (36.9) 739 (35.1) 1.08 (0.95-1.23) 0.23 
SHMT1        
    rs64333 5′ UTR N/A‡ A 677 (30.7) 636 (28.7) 1.10 (0.97-1.25) 0.15 
    rs2273028 Intron 7 N/A‡ T 725 (32.9) 691 (31.2) 1.08 (0.96-1.23) 0.22 
    rs1979277, C1420T Exon 12 Leu → Phe A 702 (31.8) 675 (30.6) 1.06 (0.93-1.20) 0.39 
TYMS        
    rs502396 Intron 1 N/A‡ C 1,078 (49.0) 1,057 (47.9) 1.04 (0.93-1.17) 0.50 
    rs1001761 Intron 2 N/A‡ T 1,067 (49.3) 1,016 (47.0) 1.09 (0.97-1.23) 0.15 
    rs699517 3′ UTR N/A‡ T 733 (33.2) 693 (31.2) 1.09 (0.96-1.23) 0.20 
DHFR        
    rs836821 Intron 2 N/A‡ T 552 (25.0) 594 (26.8) 0.91 (0.79-1.04) 0.16 
    rs1677693 Intron 3 N/A‡ A 550 (25.0) 581 (26.5) 0.93 (0.81-1.06) 0.26 
    rs1643638 Intron 4 N/A‡ C 547 (24.9) 589 (26.6) 0.92 (0.80-1.05) 0.20 
MTHFD1        
    rs1076991 5′ UTR N/A‡ G 1,017 (46.1) 1,022 (46.5) 0.98 (0.87-1.11) 0.78 
    rs1950902, R134K Exon 6 Arg → Lys T 413 (18.7) 411 (18.5) 1.01 (0.87-1.17) 0.91 
    rs2236225, R653Q Exon 20 Arg → Gln T 1,039 (47.3) 1,006 (46.0) 1.05 (0.93-1.19) 0.39 
    rs2236224 Intron 21 N/A‡ T 919 (41.5) 911 (41.0) 1.02 (0.90-1.15) 0.78 
FTHFD (ALDH1L1)        
    rs7617733 Intron 1 N/A‡ A 379 (17.1) 360 (16.2) 1.06 (0.91-1.24) 0.46 
    rs4646701 Intron 2 N/A‡ A 854 (38.7) 868 (39.4) 0.98 (0.86-1.10) 0.69 
    rs1823213 Intron 2 N/A‡ A 737 (33.4) 765 (34.5) 0.96 (0.85-1.09) 0.50 
    rs2276731 Intron 4 N/A‡ C 411 (18.7) 418 (18.8) 0.99 (0.85-1.15) 0.90 
    rs10934751 Intron 8 N/A‡ G 1,066 (48.1) 1,066 (48.0) 1.00 (0.89-1.13) 0.94 
    rs1965848 Intron 8 N/A‡ T 896 (40.7) 906 (41.1) 0.98 (0.87-1.11) 0.80 
    rs2886059 Exon 9 Val → Phe T 357 (16.1) 352 (15.9) 1.01 (0.86-1.19) 0.88 
    rs11923466 Intron 9 N/A‡ C 920 (42.1) 911 (41.3) 1.03 (0.91-1.16) 0.64 
    rs2002287 Intron 13 N/A‡ C 766 (34.6) 771 (34.8) 0.99 (0.88-1.12) 0.88 
    rs2365004 Intron 14 N/A‡ A 768 (34.6) 773 (34.9) 0.99 (0.87-1.12) 0.85 
    rs6774437 Intron 16 N/A‡ A 1,065 (48.0) 1,051 (47.3) 0.97 (0.86-1.09) 0.65 
    rs2290053 Intron 18 N/A‡ A 1,085 (49.2) 1,099 (49.9) 1.03 (0.91-1.16) 0.63 
    rs1127717, A2380C Exon 21 Asp → Gly G 490 (22.2) 452 (20.4) 1.12 (0.97-1.29) 0.13 

Abbreviations: AA, amino acid; UTR, untranslated region; OR, odds ratio; 95% CI, 95% confidence interval.

*

Per allele odds ratio, adjusted for gender, age, and draw date.

†

P for trend, adjusted for gender, age, and draw date.

‡

N/A: nonapplicable because SNP is not located in a coding region.

View Large

The genotyped SNPs included seven tagging SNPs that defined three separate haplotype blocks in the FTHFD gene. None of the haplotype blocks [(a) defined by rs2365004 and rs11923466; (b) defined by rs2886059, rs10934751, and rs2276731; (c) third was defined by rs1823213 and rs4646701] were associated with altered risk of all prostate cancer or advanced prostate cancer.

This study is the first to investigate 9 one-carbon metabolism genes in prostate cancer and uses one of the largest study populations for this purpose to date. With 1,144 cases and 1,144 controls, this study has ≥80% power to detect odds ratios as low as 1.3 for SNPs with minor allele frequencies of ≥25% and as low as 1.45 for SNPs with minor allele frequencies of ≥10%. Thus, this study was adequately powered to detect associations with common genetic variants of the magnitude typically observed.

Our null findings are consistent with the results of all (12, 14-16) but one (13) of the previous studies. The study that reported a significant association of prostate cancer risk with the MTHFR C677T SNP was based on only 21 cases of prostate cancer (13). Besides the MTHFR gene, only two other genes in one-carbon metabolism have been investigated in relation to prostate cancer. Similar to our findings, neither the nonsynonymous A2756G SNP in MTR (12, 16) nor an insertion/deletion polymorphism in CBS (12) were significantly associated with altered prostate cancer risk.

Our findings of no significant association for 39 SNPs in 9 genes involved in one-carbon metabolism suggest that perturbations in the enzymes in this pathway have little or no effect on prostate cancer incidence. Coupled with previous null findings for folate intake (4, 6, 7) or blood levels (8, 11), these results argue that altered folate nutrition or metabolism do not contribute to risk for prostate cancer.

No potential conflicts of interest were disclosed.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1
Sanjoaquin MA, Allen N, Couto E, et al. Folate intake and colorectal cancer risk: a meta-analysis approach.
Int J Cancer
 
2005
;
113
:
825
–8.
2
Hubner RA, Muir KR, Liu J-F, et al. Folate metabolism polymorphisms influence risk of colorectal adenoma recurrence.
Cancer Epidemiol Biomarkers Prev
 
2006
;
15
:
1607
–13.
3
Jemal A, Siegel R, Ward E, et al. Cancer Statistics, 2007.
CA Cancer J Clin
 
2007
;
57
:
43
–66.
4
Vlajinac HD, Marinkovic JM, Ilic MD, et al. Diet and prostate cancer: a case-control study.
Eur J Cancer
 
1997
;
33
:
101
–7.
5
Pelucchi C, Galeone C, Talamini R, et al. Dietary folate and risk of prostate cancer in Italy.
Cancer Epidemiol Biomarkers Prev
 
2005
;
14
:
944
–8.
6
Stevens VL, Rodriguez C, Pavluck AL, et al. Folate nutrition and prostate cancer incidence in a large cohort of US men.
Am J Epidemiol
 
2006
;
163
:
989
–96.
7
Weinstein SJ, Stolzenberg-Solomon R, Pietinen P, et al. Dietary factors of one-carbon metabolism and prostate cancer risk.
Am J Clin Nutr
 
2006
;
84
:
929
–35.
8
Weinstein SJ, Hartman TJ, Stolzenberg-Solomon R, et al. Null association between prostate cancer and serum folate, vitamin B6, vitamin B12, and homocysteine.
Cancer Epidemiol Biomarkers Prev
 
2003
;
12
:
1271
–2.
9
Hultdin J, Van Guelpen B, Bergh A, et al. Plasma folate vitamin B12, and homocysteine and prostate cancer risk: a prospective study.
Int J Cancer
 
2005
;
113
:
819
–24.
10
Rossi E, Hung J, Beilby JP, et al. Folate levels and cancer morbidity and mortality: prospective cohort study from Busselton, Western Australia.
Ann Epidemiol
 
2006
;
16
:
206
–12.
11
Johansson M, Appleby PN, Allen NE, et al. Circulating concentrations of folate and vitamin B12 in relation to prostate cancer risk: results from the European prospective investigation into cancer and nutrition study.
Cancer Epidemiol Biomarkers Prev
 
2008
;
17
:
279
–85.
12
Kimura F, Franke K, H., Steinhoff C, et al. Methyl group metabolism gene polymorphisms and susceptibility to prostatic carcinoma.
Prostate
 
2000
;
45
:
225
–31.
13
Heijmans BT, Boer JMA, Suchiman HED, et al. A common variant of the methylenetetrahydrofolate reductase gene (1p36) is associated with an increased risk of cancer.
Cancer Res
 
2003
;
63
:
1249
–53.
14
Cicek MS, Nock NL, Conti DV, et al. Relationship between methylenetetrahydrofolate reductase C677T and A1298C genotypes and haplotypes and prostate cancer risk and aggressiveness.
Cancer Epidemiol Biomarkers Prev
 
2004
;
13
:
1331
–8.
15
Johansson M, Van Guelpen B, Hultdin J, et al. The MTHFR 677C->T polymorphism and risk of prostate cancer: results from the CAPs study.
Cancer Causes Control
 
2007
;
18
:
1169
–74.
16
Marchal C, Redondo M, Reyes-Engel A, et al. Association between polymorphisms of folate-metabolizing enzymes and risk of prostate cancer.
Eur J Surg Oncol
 
2008
;
34
:
805
–10.
17
Calle EE, Rodriguez C, Jacobs EJ, et al. The American Cancer Society Cancer Prevention Study II Nutrition Cohort.
Cancer
 
2002
;
94
:
2490
–501.
18
Rothman KJ, Greenland S. Modern Epidemiology. Baltimore: Lippincott, Williams and Wilkens; 1998.
19
Gabriel SB, Schaffner SF, Nguyen H, et al. The structure of haplotype blocks in the human genome.
Science
 
2002
;
296
:
2225
–9.
20
Stram DO, Pearce CL, Bretsky P, et al. Modeling and E-M estimation of haplotype-specific relative risks from genotype data from a case-control study of unrelated individuals.
Hum Hered
 
2003
;
55
:
179
–90.
American Association for Cancer Research
2008