Effects of selenium and zinc supplementation on nutritional status in patients with cancer of digestive tract

Objective: To evaluate the effect of oral administration of selenium and zinc tablets in patients with cancer of the digestive tract during chemotherapy. Design: A case-control, randomized study. Setting: Medical Oncology, II University of Naples, Naples, Italy. Subjects: A total of 60 patients (median age 55 y, range 46-61 y) with diagnosis of gut cancer were randomized in 1999. Patients were treated for 60 days with chemotherapy. Interventions: Trace elements were measured by atomic absorption spectroscopy. The nutritional status of the patients was assessed by biochemical and bio-impedance analysis (BIA) parameters in basal condition and after 60 days of treatment. Oral administration of selenium and zinc in oral tablet form for 50 days was Se 200 mug/day (50 mug/tablet) and Zn 21 mg/day (7 mg/tablet). Results: Both in the basal condition and at 60 days all patients were malnourished. Selenium and zinc concentrations were significantly lower (P < 0.01) whereas copper concentration was significantly higher (P < 0.01) in cancer patients than in control subjects. However, 21/30 (70%) of those treated with Se and Zn did not showed a further worsening of nutritional status and experienced a significant decrease of asthenia with an increase of appetite. On the other hand, 24/30 (80%) untreated patients had a significant decline of all parameters studied after 60 days (prealbumin, cholesterol, transferrin, P < 0.05 vs 0 time; total proteins, albumin/globulin ratio, P < 0.01 vs 0 time; fat-free mass, fat mass, Na+/K+ ratio, body mass index P < 0.05 vs 0 time; fat free mass/fat mass, total body water, extra cellular/intra cellular water, basal metabolic rate: P < 0.01 vs 0 time). Conclusions: Data indicate that Se and Zn supplementation may improve the clinical course of general conditions in patients with gut cancer. These effects of Se and Zn require confirmation in an independent trial of appropriate design before new public health recommendations regarding Se and Zn supplementation can be made.