Is vitamin D just a proxy for health status or could supplementation be a therapeutic option? Image © R_Szatkowski / Shutterstock.com
Low levels of vitamin D may be associated with poor survival in patients with follicular lymphoma, according to the results of a prospective analysis of two cohorts of previously untreated patients starting therapy with CHOP chemotherapy and an antibody.
Looking at patients from SWOG clinical trials S9800, S9911, or S0016 and from the Lymphoma Study Association PRIMA trial, Jennifer L. Kelly, MPH, PhD, of the Wilmot Cancer Center at the University of Rochester School of Medicine and Dentistry, and colleagues found that patients with vitamin D insufficiency had a progression-free survival 1.5 to 2 times worse than patients with higher levels of vitamin D. In the SWOG cohort, vitamin D insufficiency was also linked with significantly worse overall survival.
“Our observations indicate that vitamin D insufficiency is relevant to outcomes in follicular lymphoma, and the impact on survival confirmed in two independent cohorts suggests that it is a robust predictive factor for patients with follicular lymphoma being treated with R-CHOP therapy,” Kelly and colleagues wrote in the Journal of Clinical Oncology. “Together with the accumulating evidence to support the relevance of vitamin D in other lymphoma subtypes, these findings warrant further investigation.”
Participants in the SWOG trial were previously untreated for their follicular lymphoma and treated with CHOP chemotherapy plus an anti-CD20 antibody between 1998 and 2008. Fifteen percent of patients were classified as vitamin D deficient (< 20 ng/dL).
With a median follow-up of 5.4 years, the researchers found that patients with vitamin D deficiency had a significantly worse progression-free survival (hazard ratio [HR] = 2; P = .011) and overall survival (HR = 3.57; P = .003), compared with those patients with higher vitamin D levels.
According to the researchers, “the magnitude and significance of these associations remained after analyses were stratified by treatment trial and adjusted for prognostic index (IPI), BMI, quarter of enrollment, latitude, and a quarter-by-latitude interaction term,” resulting in an adjusted progression-free survival HR of 1.97 and an adjusted overall survival HR of 4.16.
Participants in the PRIMA trial were assigned to rituximab plus chemotherapy between 2004 and 2007. Twenty-five percent of patients were classified as vitamin D deficient (< 10 ng/dL). With a median follow-up of 6.6 years, patients with vitamin D deficiency had significantly worse progression-free survival (HR = 1.66; P = .013), but the difference in overall survival was not significant (HR = 1.84; P = .14). The magnitude of these associations remained in the adjusted analysis.
“Future research is needed to determine whether vitamin D represents a proxy for health status or whether supplementation with vitamin D may be an attractive therapeutic option to ultimately change the natural history of this still incurable disease,” the researchers wrote.