The relationship between circulating 25-hydroxyvitamin D and survival in newly diagnosed advanced non-small-cell lung cancer

Abstract

Background: Serum 25-hydroxyvitamin D [25(OH)D], the major circulating form of vitamin D used for evaluating the vitamin D status of patients, has been associated with survival in a variety of cancers with conflicting evidence. We aimed to investigate this association in newly diagnosed advanced non-small-cell lung cancer (NSCLC) patients. Methods: This was a consecutive cohort of 359 newly diagnosed stages III-IV NSCLC patients who underwent a baseline serum 25(OH)D evaluation prior to receiving any treatment at our institution between January 2008 and December 2010. We used the vitamin D categories of "deficient ( < 20 ng/ml)" and "not deficient (> = 20 ng/ml)". Cox regression was used to evaluate the prognostic significance of serum 25(OH)D after adjusting for relevant confounders. Results: Mean age at diagnosis was 57.4 years. Of the 359 patients, 151 (42.1 %) were deficient in vitamin D at the time of diagnosis. The median survival in deficient and not deficient cohorts was 11.7 and 12.8 months respectively (p = 0.06). Season of diagnosis, performance status, smoking status and hospital location significantly predicted vitamin D status. On univariate Cox analysis, gender, stage of disease, hospital location, histologic subtype, subjective global assessment (SGA), performance status, smoking status, body mass index and serum albumin were significantly associated with survival (p < 0.05 for all). On multivariate Cox analysis, six variables demonstrated statistically significant associations with survival: stage of disease, hospital location, histologic subtype, SGA, smoking status and serum albumin (p < 0.05 for all). Serum vitamin D, which was borderline significant in univariate analysis, lost its significance in multivariate analysis. Conclusions: We found season of diagnosis, performance status and smoking history to be predictive of vitamin D status. Consistent with previously published research in advanced NSCLC, we did not find any significant association between pre-treatment serum 25(OH)D and survival in our patients.