Cigarette smoking and lung cancer - relative risk estimates for the major histological types from a pooled analysis of case-control studies
Abstract
By using one of the largest lung cancer datasets ever assembled, we explored the impact of smoking on risks of the major cell types of lung cancer. This pooled analysis included 13,169 cases and 16,010 controls from Europe and Canada.
Studies with population controls comprised 66.5% of the subjects. Adenocarcinoma (AdCa) was the most prevalent subtype in never smokers and in women.
Squamous cell carcinoma (SqCC) predominated in male smokers. Although ORs started to decline soon after quitting, they did not fully return to the baseline risk of never smokers even 35 years after cessation.
The major result that smoking exerted a steeper risk gradient on SqCC and SCLC than on AdCa is in line with previous population data and biological understanding of lung cancer development.