Micronutrient status influences clinical outcomes of paediatric cancer patients during treatment: A prospective cohort study

Abstract

Background: Research reporting plasma micronutrient status and its impact on clinical outcomes in paediatric cancer is scarce. Therefore, we investigated the prevalence of plasma micronutrient abnormalities and their impact on clinical outcomes and treatment complications.

Methods: A multicentre prospective-cohort study of children aged <18 years diagnosed with cancer was performed between Aug 2010-Jan 2014. Clinical and nutritional data were collected at diagnosis, 3, 6, 9, 12 and 18 months. Micronutrient status was established using in-house laboratory references (vitamin B12, vitamin A and Vitamin E/Ch) and aged adjusted Z-scores (Mg, Se, Zn and Cu) generated from a cohort of healthy Scottish children. Clinical outcomes were classified as "event free survival (EFS)" or "event" (relapse, death, new metastasis or becoming palliative) and treatment complications. Descriptive statistics, logistic regression and multilevel analysis were performed.

Results: Eighty-two patients [median (IQR) 3.9 (1.9-8.8) years, 56% males] were recruited. Of these, 72 (88%) samples were available, 74% (53/72) patients had micronutrient abnormalities at baseline; deficiencies (25%, 18/72), excesses (19%, 14/72) and a combination of both (29%, 21/72), which continued for 18 months. Vitamin A deficiency (15%, 3/20) and excess (50%, 10/20) were most prevalent at 18 months, whilst vitamin E/Cholesterol and vitamin B12 were mostly within the normal range. Prevalence of Zn deficiency at diagnosis was 36% (16/44 adjusted for CRP), which remained at these levels throughout the study. Reduction in each selenium concentration unit increased the odds of an event by 2% (OR 0.02) and lower Se predicted higher complications at diagnosis [β (-1.2); t (-2.1); 95% CI (-2.9 - (-0.04)); p = 0.04], 3 months [β (-3.9); t (-4.2); 95% CI (-5.57 - (-2.02)); p < 0.001] and 12 months [β (-2.3); t (-2.4); 95% CI (-4.10 - (-0.34)); p = 0.02].

Conclusions: Given the prevalence of micronutrient abnormalities and the negative impact of low selenium on clinical outcome, micronutrient status should be assessed and monitored in paediatric cancer patients. Larger multicentre population based studies and clinical trials are now warranted.

Keywords: Childhood cancer; Micronutrient; Minerals; Paediatrics; Vitamins.