BMC Cancer (Jun 2010)

Cigarette smoking, genetic polymorphisms and colorectal cancer risk: the Fukuoka Colorectal Cancer Study

  • Maekawa Takafumi,
  • Futami Kitaroh,
  • Ikejiri Koji,
  • Okamura Takeshi,
  • Maehara Yoshihiko,
  • Kakeji Yoshihiro,
  • Tanaka Masao,
  • Mibu Ryuichi,
  • Nagano Jun,
  • Toyomura Kengo,
  • Yin Guang,
  • Kono Suminori,
  • Nisa Hoirun,
  • Yasunami Yohichi,
  • Takenaka Kenji,
  • Ichimiya Hitoshi,
  • Terasaka Reiji

DOI
https://doi.org/10.1186/1471-2407-10-274
Journal volume & issue
Vol. 10, no. 1
p. 274

Abstract

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Abstract Background It is uncertain whether smoking is related to colorectal cancer risk. Cytochrome P-450 CYP1A1, glutathione-S-transferase (GST) and NAD(P)H:quinone oxidoreductase 1 (NQO1) are important enzymes in the metabolism of tobacco carcinogens, and functional genetic polymorphisms are known for these enzymes. We investigated the relation of cigarette smoking and related genetic polymorphisms to colorectal cancer risk, with special reference to the interaction between smoking and genetic polymorphism. Methods We used data from the Fukuoka Colorectal Cancer Study, a population-based case-control study, including 685 cases and 778 controls who gave informed consent to genetic analysis. Interview was conducted to assess lifestyle factors, and DNA was extracted from buffy coat. Results In comparison with lifelong nonsmokers, the odds ratios (OR) of colorectal cancer for CYP1A1*2A or CYP1A1*2C and GSTT1 polymorphisms was associated with a decreased risk of colorectal cancer, showing a nearly statistically significant (Pinteraction = 0.06) or significant interaction (Pinteraction = 0.02). The composite genotypes of these two polymorphisms, however, showed no measurable interaction with cigarette smoking in relation to colorectal cancer risk. Conclusions Cigarette smoking may be associated with increased risk of rectal cancer, but not of colon cancer. The observed interactions between CYP1A1 and GSTT1 polymorphisms warrant further confirmation.