Background:
There is observational evidence suggesting that high vitamin D
concentrations may protect against lung cancer. To investigate this
hypothesis in detail, we measured circulating vitamin D concentrations in pre-diagnostic blood from 20 cohorts participating in the Lung Cancer Cohort Consortium (LC3).
Patients and methods:
The study included 5,313 lung cancer cases and
5,313 controls selected from. Blood samples for the cases were collected, on average, 5 years prior to lung cancer diagnosis. Controls were individually matched to the cases by cohort, sex, age, race/ethnicity, date of blood
collection, and smoking status in 5 categories. Liquid chromatography
coupled with tandem mass spectrometry was used to separately analyze 25-hydroxyvitamin D2 (25(OH)D2) and 25-hydroxyvitamin D3 (25(OH)D3) and their concentrations were combined to give an overall measure of 25(OH)D. We used conditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI) for 25(OH)D as both a continuous and categorical variable.
Results:
Overall, no apparent association between 25(OH)D and risk of lung
cancer was observed (multivariable adjusted OR for a doubling in
concentration: 0.98, 95% confidence interval: 0.91, 1.06). Similarly, we found no clear evidence of interaction by cohort, sex, age, smoking status, or
histology.
Conclusion:
This study did not support an association between vitamin D concentrations and lung cancer risk