Zinc deficiency and its association with treatment-related toxicity in children with cancer

Background: Nutritional deficiencies in children with cancer at time of diagnosis and during treatment may negatively affect disease outcome and increase treatment-related toxicity. Yet zinc, an essential nutrient important for supporting immune function and known for reducing diarrheal episodes, is rarely assessed in these children.

Procedures: Fifty children (1 month to 18 years) with recently diagnosed cancer were enrolled in this study. An age and gender matched control group (n = 50) was also recruited. Plasma and urinary zinc, plasma copper, and C-reactive protein (CRP) levels were measured at baseline, 3, and 6 months following diagnosis. A retrospective review of the toxicity profile was performed in the cohort of children with cancer for the first 4 years after initial diagnosis.

Results: CRP and plasma copper (both acute-phase reactants) were elevated in patients with cancer compared to controls at baseline, both p < .03. Plasma zinc levels were not significantly different from controls at baseline, but decreased by 11% in the cancer group over 6 months of treatment, 83.2 ± 15.6 to 74.3 ± 14.8 μg/dl, p = .01. Plasma zinc dropped to deficient levels in 35% of cases over the initial 6 months. Zinc deficiency at 6 months was related to an increased incidence of severe diarrhea during 4 years of follow-up, p < .001.

Conclusions: Zinc deficiency is an underrecognized problem among patients undergoing treatment for cancer and is associated with severe diarrhea. Further studies are needed to evaluate causes for zinc deficiency, related effects, and a possible role for zinc supplementation.