The importance of exposure rate on odds ratios by cigarette smoking and alcohol consumption for esophageal adenocarcinoma and squamous cell carcinoma in the Barretts Esophagus and Esophageal Adenocarcinoma Consortium Cancer Epidemiology, 05/15/2012

Lubin JH et al. – Patterns of ORs by pack-years and drink-years, delivery rate effects and effect modifiers revealed common as well as distinct etiologic elements for these diseases.

• The authors pooled data from 12 case–control studies from the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium (BEACON), including 1242 (EAC), 1263 (EGJA) and 954 (ESCC) cases and 7053 controls, modeled joint ORs for cumulative exposure and exposure rate for cigarette smoking and alcohol consumption, and evaluated effect modification by sex, body mass index (BMI), age and self-reported acid reflux

• For smoking, all sites exhibited inverse delivery rate effects, whereby ORs with pack-years increased, but trends weakened with increasing cigarettes/day.
• None of the examined factors modified associations, except for ESCC where younger ages at diagnosis enhanced smoking effects (P<0.01). For EAC and EGJA, ORs with drink-years exhibited inverse associations in <5drinks/day consumers and no association in heavier consumers.
• For ESCC, ORs with drink-years increased, with trends strengthening with greater drinks/day.
• There was no significant effect modification, except for EAC and EGJA where acid reflux mitigated the inverse associations (P=0.02).
• For ESCC, younger ages at diagnosis enhanced drinking-related ORs (P<0.01).