Vitamin D deficiency may negatively impact outcomes in patients with follicular lymphoma (FL), according to research published in the Journal of Clinical Oncology.
The study showed that FL patients with vitamin D deficiency had inferior progression-free survival (PFS) and overall survival (OS) compared to patients with higher vitamin D levels.
According to researchers, this suggests serum vitamin D might be the first potentially modifiable factor to be associated with survival in FL.
However, additional research is needed to determine the effects of vitamin D supplementation in these patients.
Jonathan W. Friedberg, MD, of the Wilmot Cancer Institute at the University of Rochester in New York, and his colleagues conducted this research, analyzing data from 2 cohorts of FL patients.
One cohort consisted of patients derived from 3 SWOG trials (S9800, S9911, and S0016), and the other consisted of patients from a Lymphoma Study Association (LYSA) trial known as PRIMA.
SWOG patients had received CHOP chemotherapy plus an anti-CD20 antibody (rituximab or iodine-131 tositumomab), and LYSA patients had received rituximab plus chemotherapy (and were randomized to rituximab maintenance or observation).
SWOG cohort
After a median follow-up of 5.4 years, patients with vitamin D deficiency (defined as <20 ng/mL) had significantly inferior PFS (hazard ratio [HR]=2.00; P=0.011) and OS (HR=3.57; P=0.003) compared to patients with higher vitamin D levels.
Results were similar when the researchers adjusted for other variables, such as prognostic index (IPI), body mass index, and latitude (≥ vs <35°N). For PFS, the adjusted HR was 1.97 (P=0.023). And for OS, the adjusted HR was 4.16 (P=0.002).
Multivariable analysis of vitamin D by tertile confirmed that the lowest tertile of vitamin D was associated with a greater increase in the risk of either progression or death, but neither result was significant.
LYSA cohort
After a median follow-up of 6.6 years, patients with vitamin D deficiency (defined as <10 ng/mL) had significantly inferior PFS (HR=1.66; P=0.013) but not OS (HR=1.84; P=0.14) compared to patients with higher vitamin D levels.
Results were similar when the researchers adjusted for other variables, such as prognostic index (FLIPI), body mass index, latitude (Europe vs Australia), and hemoglobin. For PFS, the adjusted HR was 1.50 (P=0.095). For OS, the adjusted HR was 1.92 (P=0.192).
Multivariable analysis of vitamin D by tertile confirmed that the lowest tertile of vitamin D was associated with a greater increase in the risk of either progression or death, but only the association with OS reached statistical significance (HR=5.32; P=0.037).
Dr Friedberg said that, taken together, these results suggest vitamin D levels may be a modifiable factor associated with prognosis in patients with FL.
“Our data, replicated internationally, supports other published observations linking vitamin D deficiency with inferior cancer outcomes,” he said. “However, the mechanisms of this link are likely complex and require further study.”
