Serum 25-hydroxyvitamin D levels correlate with EGFR mutational status in pulmonary adenocarcinoma

There have been several epidemiological studies of the association between 25-hydroxyvitamin D (25(OH)D) level and lung cancer risk. We explored the potential association between serum 25(OH)D levels and mutations in epidermal growth factor receptor (EGFR) in patients with pulmonary adenocarcinoma. We analyzed clinical data from 135 patients whose serum 25(OH)D levels were measured and EGFR mutational status was tested at the time of diagnosis. The relationship between 25(OH)D and clinical factors such as EGFR mutational status and sex was examined. The median serum 25(OH)D level in patients with pulmonary adenocarcinoma was 16.8 ng/ml (range: 3.0-84.3 ng/ml). The level of 25(OH)D was lower in female patients than in male patients (P=0.03). Interestingly, 25(OH)D levels of patients with EGFR-mutated tumors were low compared with those with wild-type tumors (median 18.2 vs 14.7 ng/ml, P=0.011). After a dose-response relationship between EGFR mutations and 25(OH)D levels (as a continuous variable) was observed (OR=0.96, P=0.036), we categorized 25(OH)D levels as low (≤16.8 ng/ml) and high (>16.8 ng/ml). Multivariate analysis revealed the association between low 25(OH)D levels and a high incidence of EGFR mutations (adjusted OR=2.42, 95% CI: 1.11-5.26, P=0.026). The results from this study indicate that low 25(OH)D levels are associated with EGFR mutations in pulmonary adenocarcinoma.