CHICAGO–Higher concentrations of plasma vitamin D are associated with significantly improved survival in patients with metastatic colorectal cancer treated with chemotherapy plus biologics, a study presented at the 2015 American Society of Clinical Oncology (ASCO) annual meeting in Chicago, IL, has shown.
“Metastatic colorectal patients are frequently vitamin D deficient,” Kimmie Ng, MD, MPH, medical oncologist at Dana-Farber Cancer Institute and Brigham and Women’s Hospital in Boston, MA, said when providing background on the study.
For the study, researchers analyzed data from 1,043 patients with metastatic colorectal cancer who participated in the phase III CALGB/SWOG 80405 trial. Patients were randomly assigned to receive chemotherapy plus bevacizumab, cetuximab, or both.
Results of this analysis showed that patients in the highest quintile of plasma vitamin D concentrations had significantly improved overall survival compared with those in the lowest quintile (median 32.6 months vs. 24.5 months; HR: 0.65; 95% CI: 0.51,0.83; P trend=0.001).
“Patients with the highest levels of vitamin D have a 35% improvement in overall survival,” Dr. Ng said.
Researchers also found that increasing concentrations of vitamin D were significantly associated with improved median progression-free survival (12.2 months vs. 10.1 months; HR: 0.79; 95% CI: 0.63,0.99; P trend=0.01).
“Patients with the highest levels of vitamin D have a 21% improvement in progression-free survival,” Dr. Ng added. The study showed that male and black patients, those with lower dietary and supplemental vitamin D intake, patients living in the northeast, patients with an ECOG performance status 1, patients with tumoral RAS mutation, patients with higher BMI, and patients with lower physical activity had significantly lower levels of vitamin D with a median plasma vitamin D level of 17.2ng/mL among all patients.
A randomized, phase II trial to assess the effect of vitamin D supplementation in patients with metastatic colorectal cancer receiving FOXLOX plus bevacizumab is currently ongoing.
1. Ng K, Venook AP, Sato K, et al. Vitamin D status and survival of metastatic colorectal cancer patients: Results from CALGB/SWOG 80405 (Alliance). J Clin Oncol. 2015;33:(suppl; abstr 3503).