In an analysis reported in the Journal of Clinical Oncology, Kelly et al found that low baseline serum vitamin D levels are associated with poorer progression-free and overall survival in patients with previously untreated follicular lymphoma.
The study involved analysis of data from two patient cohorts: 183 previously untreated U.S. patients in Southwest Oncology Group (SWOG) clinical trials (S9800, S9911, and S0016) involving CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) plus an anti-CD20 antibody (rituximab [Rituxan] or iodine-131 tositumomab [Bexxar]) treated between 1998 and 2008; and 240 previously untreated patients (from France, Belgium, and Australia) from the Lymphoma Study Association (LYSA) PRIMA trial of rituximab plus chemotherapy treated between 2004 and 2007.
Levels of 25-hydroxyvitamin D were measured in stored baseline serum samples using liquid chromatography-tandem mass spectrometry. Vitamin D deficiency was defined as levels < 20 ng/mL in the SWOG cohort analysis and < 10 ng/mL in the LYSA cohort analysis.
Progression-Free and Overall Survival
After median follow-up of 5.4 years in the SWOG cohort, adjusted hazard ratios (HRs) were 1.97 (95% confidence interval [CI] = 1.10–3.53) for progression-free survival and 4.16 (95% CI = 1.66–10.44) for overall survival for patients with vitamin D deficiency (< 20 ng/mL, 15% of cohort) vs patients without deficiency.
After median follow-up of 6.6 years in the LYSA cohort, adjusted hazard ratios were 1.50 (95% CI = 0.93–2.42) for progression-free survival and 1.92 (95% CI = 0.72–5.13) for overall survival for patients with deficiency (< 10 ng/mL, 25% of cohort) vs those without deficiency.
The investigators concluded: “Although statistical significance was not reached in the LYSA cohort, the consistent estimates of association between low vitamin D levels and [follicular lymphoma] outcomes in two independent cohorts suggests that serum vitamin D might be the first potentially modifiable factor to be associated with [follicular lymphoma] survival. Further investigation is needed to determine the effects of vitamin D supplementation in this clinical setting.”
Jonathan W. Friedberg, MD, of the University of Rochester School of Medicine and Dentistry, is the corresponding author for the Journal of Clinical Oncology article.
The study was supported by the National Cancer Institute, GlaxoSmithKline, National Heart Lung and Blood Institute, and Lymphoma Research Foundation.
For full disclosures of the study authors, visit jco.ascopubs.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.