Annals of Oncology, Vol 29, Issue suppl_9, 1 Nov 2018, https://doi.org/10.1093/annonc/mdy431.042
D Ng R Tan R Sultana M Ang W Lim D Chong C Cwl S-L Koo S Seet Z Tan I B Tan
Background: Limited data is available on the association between Vitamin D (vD) levels and outcomes in patients with colorectal cancer in Asians. This study aims to investigate the prevalence of vD deficiency in Stage II and III Chinese colorectal cancer patients in Singapore and their prognostic implications.
Methods: We prospectively included colorectal cancer patients who underwent adjuvant chemotherapy at the National Cancer Centre, Singapore. Plasma 25-hydroxyl-vitamin D levels were measured before adjuvant chemotherapy using a Roche E411 analyzer. Information on demographic, risk factors, lifestyle and dietary characteristics of recruited patients were collected using an abbreviated food and exercise frequency questionnaire and verified against their medical records. Plasma vD levels were categorized as deficient (<20ng/ml), insufficient (21-30ng/ml) and sufficient (>30ng/ml). Study variables were compared with vD categories. Kaplan-Meier plots and Cox proportional hazard regression models were used to examine the associations between vD categories, progression-free survival (PFS) and overall survival (OS).
Results: Fifty-six patients (mean age 62 years; 61.0% men) with Stage II to III colorectal cancer were recruited; 48.0% were categorized as deficient, 37.5% were insufficient and 14.5% were sufficient in vD levels. Median time from surgery to blood sampling was 17 days (interquartile range [IQR], 4 to 20 days). Differences in tumour characteristics, time from surgery to sampling, self-reported vD intake, time spent outdoors or body mass index were not significantly associated with vD categories. Lower red meat intake was associated with Vitamin D deficiency (p = 0.007). Median follow was 22 months (IQR 17 to 28 months).
Hazard ratios (HR) were 1.43 (0.16, 12.92) and 2.89 (0.35, 24.16) for deficient and insufficient group respectively for PFS (p = 0.42) with respect to sufficient vD group.
Similarly, HRs were 0.12 (0.01, 1.52) and 0.30 (0.04, 2.44) for insufficient and deficient group respectively for OS (p = 0.25).