Lower vitamin D levels were associated with poorer overall survival, melanoma-specific survival, and disease-free survival independent of a strong association between lower vitamin D and higher C-reactive protein, a study published in the Journal of Clinical Oncology has shown.1

For the study, researchers sought to evaluate the association between vitamin D levels and outcome measures in patients with melanoma after controlling for systemic inflammatory response by simultaneously measuring C-reactive protein.

Researchers assayed plasma samples from 1042 prospectively observed patients with melanoma for vitamin D and C-reactive protein. Vitamin D levels of 30 to 100 ng/mL were considered to be sufficient.

Results showed that at a median follow-up of 7.1 years, a lower vitamin D level was associated with the blood draw during the fall or winter months (P<.001), older age (P=.001), increased C-reactive protein (P<.001), increased tumor thickness (P<.001), ulcerated tumor (P=.0105), and advanced melanoma stage (P=.0024).

In terms of outcome measures, researchers found that lower vitamin D was associated with poorer overall survival (P<.001), melanoma-specific survival (P=.0025), and disease-free survival (P=.0466). This association persisted after researchers adjusted for C-reactive protein and other variables.

The study also demonstrated that each unit reduction in vitamin D improved the risk for overall survival (HR, 1.02; 95% CI: 1.01-1.04; P=.0051), melanoma-specific survival (HR, 1.02; 95% CI: 1.00-1.04; P=.048), and disease-free survival (HR, 1.02; 95% CI: 1.00-1.04; P=.0427) by 2%.

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The findings suggest that investigation into the mechanism involved in these associations may be beneficial to patients with melanoma.

Reference

  1. Fang S, Sui D, Wang Y, et al. Association of vitamin d levels with outcome in patients with melanoma after adjustment for C-reactive protein [published online ahead of print March 21, 2016]. J Clin Oncol. doi: 10.1200/JCO.2015.64.1357.