Abstract:
Tobacco smoke contains many potentially harmful compounds that may
act differently and at different stages in breast cancer development. The focus of this work
was to assess the possible role of cigarette smoking (status, dose, duration or age at initiation)
and polymorphisms in genes coding for enzymes involved in tobacco carcinogen metabolism
(CYP1A1, CYP2A6) or inDNArepair (XRCC1, APEX1, XRCC3 and XPD) in breast cancer development.
Methods: We designed a case control study with 297 patients, 217 histologically verified breast
cancers (141 smokers and 76 non-smokers) and 80 healthy smokers in a cohort of Spanish women.
Results: We found an association between smoking status and early age at diagnosis of breast cancer.
Among smokers, invasive carcinoma subtype incidence increased with intensity and duration of
smoking (all Ptrend < 0.05). When smokers were stratified by smoking duration, we only observed
differences in long-term smokers, and the CYP1A1 Ile462Ile genotype was associated with increased
risk of breast cancer (OR = 7.12 (1.98–25.59)). Conclusions: Our results support the main effect
of CYP1A1 in estrogenic metabolism rather than in tobacco carcinogen activation in breast...