Smoking-related DNA adducts in anal epithelium.
Several studies have identified tobacco smoking as a risk factor for anal cancer in both women and men. Samples of anal epithelium from haemorrhoidectomy specimens from current smokers (n = 20) and age-matched life-long non-smokers (n = 16) were analysed for DNA adducts by the nuclease P(1) digestion enhancement procedure of 32P-postlabelling analysis. The study included 14 men and 22 women. Both qualitative and quantitative differences in the adduct profiles were observed between the smokers and non-smokers. The mean adduct level was significantly higher in the smokers than in the non-smokers (1.88 +/- 0.71) (S.D.) versus 1.36 +/- 0.60 adducts per 10(8) nucleotides, P = 0.02, two-tailed unpaired t-test with Welch's correction); furthermore, the adduct pattern seen in two-dimensional chromatograms revealed the smoking-related diagonal radioactive zone in 17/20 smokers, but not in any of the non-smokers (P < 0.00001, Fisher's exact test). These results indicate that components of tobacco smoke inflict genotoxic damage in the anal epithelium of smokers and provide a plausible mechanism for a causal association between smoking and anal cancer.
Phillips
David H
DH
Institute of Cancer Research, Brookes Lawley Building, Cotswold Road, Sutton SM2 5NG, UK.
Hewer
Alan
A
Scholefield
John H
JH
Skinner
Paul
P
D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000737:chemistry*; D001005:Anus Neoplasms / Q000209:etiology; D016022:Case-Control Studies; D018736:DNA Adducts / Q000032:analysis*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000009:adverse effects*
D018736:DNA Adducts