Is voluntary vitamin and mineral supplementation associated with better outcome in non-small cell lung cancer patients? Results from the Mayo Clinic lung cancer cohort

Background: Some previous studies report that 80% of cancer patients take multivitamin and/or mineral supplements. To our knowledge, the consequences of such self-directed supplementation have not been examined previously in non-small cell lung cancer (NSCLC) patients. The goal of this study was to determine whether vitamin/mineral supplementation is associated with improved survival and quality of life in a cohort of NSCLC patients. Methods: NSCLC patients or their proxies who responded to a questionnaire on vitamin/mineral use were assessed for survival and quality of life. Results: A total of 1129 patients or their proxies responded to a vitamin/mineral questionnaire. Seven hundred and fourteen were vitamin/mineral users of either multivitamins or other specific vitamin/mineral supplements, and the rest non-users. Median survival was 4.3 years versus 2.0 years for vitamin/mineral users and non-users, respectively. A Cox proportional hazards model showed a relative risk of death of 0.74 (95% confidence interval (CI): 0.44, 0.65) (p < 0.01) in favor of vitamin/mineral use after adjustment for multiple prognostic factors, including tumor stage. The Lung Cancer Symptom Scale (LCSS) showed better quality of life among vitamin/mineral users (mean difference in score of 3 (95% CI: 0.8, 5.1) (p < 0.01); and after adjusting for related variables, there remained a trend in favor of vitamin/mineral use mean difference 1.8 (95% CI: 0.2, 3.9) (p = 0.08). Conclusions: Vitamin/mineral supplementation is associated with better survival and quality of life in this cohort of NSCLC patients. Future prospective clinical trials should focus on the role of such supplements in patients with NSCLC.