Cancer and 1-carbon metabolism

January 01, 0001

Cancer and 1-carbon metabolism

Substances related to 1-carbon metabolism, including some B- vitamins, appear to protect DNA from damage and regulate gene expression, which may affect cancer risk. These European researchers investigated if 1- carbon metabolism factors are associated with onset of lung cancer. The European Prospective Investigation into Cancer and Nutrition (EPIC) recruited 519 978 participants from 10 countries between 1992 and 2000, of whom 385 747 donated blood. Lung cancer was identified in 899 participants and 1770 matched control were also identified. Six factors of 1-carbon metabolism and cotinine were measured. (ORs) of lung cancer by serum levels of 4 B vitamins (B2, B6, folate [B9

The researchers report: "Within the entire EPIC cohort, the age- standardized incidence rates of lung cancer (standardized to the world population, aged 35-79 years) were 6.6, 44.9, and 156.1 per 100 000 person- years among never, former, and current smokers for men, respectively. The corresponding incidence rates for women were 7.1, 23.9, and 100.9 per 100 000 person-years, respectively. After accounting for smoking, a lower risk for lung cancer was seen for elevated serum levels of B6 (fourth vs first quartile OR, 0.44), as well as for serum methionine (fourth vs first quartile OR, 0.52). Similar and consistent decreases in risk were observed in never, former, and current smokers, indicating that results were not due to confounding by smoking. The magnitude of risk was also constant with increasing length of follow-up, indicating that the associations were not explained by preclinical disease. A lower risk was also seen for serum folate (fourth vs first quartile OR, 0.68), although this was apparent only for former and current smokers. When participants were classified by median levels of serum methionine and B6, having above-median levels of both was associated with a lower lung cancer risk overall (OR, 0.41), as well as separately among never (OR, 0.36), former (OR, 0.51), and current smokers (OR, 0.42)."

The authors concluded: "Serum levels of vitamin B6 and methionine were inversely associated with risk of lung cancer."

This large case-control study suggests that 1-carbon metabolism may play a role in preventing cancer, but further study is required.

For the full abstract, click here.

JAMA 303(23):2377-2385, 16 June 2010
© 2010 the American Medical Association
Serum B Vitamin Levels and Risk of Lung Cancer. Mattias Johansson, Caroline Relton, Per Magne Ueland, et al.

Category: A. General/Unspecified. Keywords: B vitamins, 1-carbon metabolism, methionine, lung cancer, EPIC, case-control, journal watch.
Synopsis edited by Dr Paul Schaefer, Toledo, Ohio. Posted on Global Family Doctor 9 July 2010

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