Abstract 492P
Background
Vitamin D (Vit.D) deficiency is a poor prognostic factor in mCRC patients (pts). To evaluate if this is attributable to an impaired immunity boosting effect, we analysed peripheral inflammatory/immune components in Vit. D deficient mCRC pts.
Methods
Pts eligible for 1st line chemotherapy were tested for serum Vit.D levels and association of Vit.D with OS was analyzed (Kaplan Meier and Cox regression methods). Differences in 24 peripheral inflammatory/immune variables [i.e.: white blood cells(WBC), neutrophils (N), lymphocytes (L), NL ratio (NLR), platelet/L ratio, monocytes, sum of mononuclear cells, systemic inflammatory index, CRP, LDH, albumin, albumin-to-globulin ratio, D-Dimer, different subsets of lymphocytes] between Vit.D deficient (<10 ng/dL) vs non-deficient (>10 ng/dL) pts were analyzed (Mann-Whitney-Wilcoxon test).
Results
135 pts were included [74 males, median(m) age 64 yrs, range 30-84]. mVit.D was 14.8 ng/ml (range 3-160); mOS for Vit D <10 ng/mL (63 pts) vs >10 ng/mL (70 pts) was 12.3 vs 24.5 months, respectively [HR 2.03, p 0.002]. Vit.D deficient pts had a significant increase in mN (69% vs 65%, p 0.04), mNLR (3.5 vs 2,9, p 0.05) and CD4+/L (48% vs 40%, p 0.04) and a significant decrease in CD19+/L (4% vs 7%, p 0.03) as compared to non-deficient pts. In Vit.D deficient pts, N count could further stratify prognosis: mOS for < vs > 6000/μl was 19.1 vs 8.1 [HR 2.76, p 0.006]. No significant difference in survival between Vit.D deficient pts with low N and non-deficient pts was observed (p 0.07).
Conclusions
Vit.D deficiency is confirmed to be a poor prognostic factor in mCRC pts and correlates with meaningful inflammatory/immune changes. The observed increase in T helper cells (CD4+) might be restricted to Th1 activation with a possible surge in proinflammatory cytokine production reflected, peripherally, by higher N and NLR values. Further evaluation of the Th1/Th2/Th17/Treg balance and effector cytokines is underway. The observed B cell (CD19+) depletion might be due to the lack of Vit.D-induced differentiation.
Clinical trial identification
Editorial acknowledgement
This research work has been conducted under the Programme on Experimental System and Medicine (XXXV cycle) at the University of Rome Tor Vergata.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.