Baseline Vitamin D Not Associated With Survival in Patients With Advanced Pancreatic Cancer in CALGB 80303/Alliance Trial
Preclinical data indicate a role of vitamin D metabolism in pancreatic tumor development. In a study reported in the Journal of the National Cancer Institute, Van Loon et al found that baseline serum 25-hydroxyvitamin D (25[OH]D) levels were not associated with progression-free survival or overall survival in patients with advanced pancreatic cancer receiving gemcitabine with or without bevacizumab (Avastin) in the Cancer and Leukemia Group B (CALGB) 80303/Alliance trial.
Study Details
In this correlative study (CALGB 151006), baseline serum vitamin D levels were available for 256 of 602 patients in the CALGB 80303 trial. The trial found no overall survival difference with gemcitabine/bevacizumab vs gemcitabine (median, 5.8 vs 5.9 months), with similar outcome among patients with available serum samples (median, 5.9 vs 5.8 months).
Vitamin D Levels
The median vitamin D level was 21.7 ng/mL (range, 4–77 ng/mL), with 44.5% of patients being vitamin D deficient (< 20 ng/mL) and 32.4% being vitamin D insufficient (≥ 20 and < 30 ng/mL). Levels were lower in black vs white patients and patients of other/undisclosed race (10.7 vs 22.4 vs 20.9 ng/mL, P < .001).
No Association With Progression-Free Survival, Overall Survival
After adjustment for race, baseline vitamin D level as a continuous variable was not associated with progression-free survival (hazard ratio [HR] = 1.00, P = .76) or overall survival (HR = 1.00, P = .97), and no significant relationships with progression-free survival or overall survival were observed among baseline vitamin D quartiles.
A log rank test for trend performed on the basis of observation of increasing progression-free survival across vitamin D quartiles (medians, 2.56, 2.78, 3.60, and 3.88 months) showed no significant association (P = .19). Median progression-free survival and overall survival were 3.84 and 4.99 months among patients with optimal vitamin D levels (≥ 36 ng/mL) and 1.99 and 4.80 months in those with very low levels (< 10 ng/mL), but the differences in progression-free survival (P = .48) and overall survival (P = .79) were not significant.
The investigators concluded: “Vitamin D deficiency was highly prevalent among patients with a new diagnosis of advanced pancreatic cancer. Black patients had statistically significantly lower 25(OH)D levels than white patients. In this cohort of patients with advanced pancreatic cancer receiving gemcitabine-based chemotherapy, baseline 25(OH)D levels were not associated with [progression-free survival] or [overall survival].”
Katherine Van Loon, MD, MPH, of UCSF Helen Diller Family Comprehensive Cancer Center, is the corresponding author for the Journal of the National Cancer Institute article.
The study was supported by grants from the American Society of Clinical Oncology, Agency for Healthcare Research and Quality, and National Cancer Institute.
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