Do genetic factors protect for early onset lung cancer? A case control study before the age of 50 years

Background: Early onset lung cancer shows some familial
aggregation, pointing to a genetic predisposition. This study was
set up to investigate the role of candidate genes in the
susceptibility to lung cancer patients younger than 51 years at
diagnosis. Methods: 246 patients with a primary, histologically or
cytologically confirmed neoplasm, recruited from 2000 to 2003 in
major lung clinics across Germany, were matched to 223 unrelated
healthy controls. 11 single nucleotide polymorphisms of genes with
reported associations to lung cancer have been genotyped.
EPHX1(His113Tyr). Carriers of the Leu-allele of GPX1(Pro200Leu)
showed a significant risk reduction of OR = 0.6 (95% CI: 0.4-0.8, p
= 0.002) in general and of OR = 0.3 (95% CI: 0.1-0.8, p = 0.012)
within heavy smokers. We could also find a risk decreasing genetic
effect for His-carriers of EPHX1(His113Tyr) for moderate smokers
(OR = 0.2, 95% CI: 0.1-0.7, p = 0.012). Considered both variants
together, a monotone decrease of the OR was found for smokers (OR
of 0.20; 95% CI: 0.07-0.60) for each protective allele. Conclusion:
Smoking is the most important risk factor for young lung cancer
patients. However, this study provides some support for the T-Allel
of GPX1(Pro200Leu) and the C-Allele of EPHX1(His113Tyr) to play a
protective role in early onset lung cancer susceptibility.