Supplementation with Selenium As Prevention for the Development of Mucositis in Patients Undergoing HSCT. Results of a Pilot Study

Introduction:

Numerous clinical trials have been conducted in order to reduce or prevent the appearance of mucositis in patients undergoing cancer treatment and some of these have appeared in the clinical guidelines as recommendations (Keefe,DM Cancer 2007). However, to date no molecule has been shown to prevent appearance of this kind of lesions. Selenium, a trace element in the organism, cofactor of multiple biological processes, has been used previously for mucositis chemoprevention in head and neck tumors. We conducted a study to know if selenium supplementation has an impact on the development of mucositis.

Objective:

We aim to know the impact of Selenium in patients undergoing hematopoietic stem cell transplantation, in the presentation and duration of mucositis comparing against placebo.

Methods: We performed a double blind clinical trial in a single center pilot study approved by our ethics committee. All patients candidates for autologous or allogeneic HSCT above 18 years were submitted for our study previous informed consent by our institution. Patients were randomized into one of two arms: a) selenium methionine, b) placebo.

Previously randomized, patients were administered supplementation with oral selenium methionine at a dose of 400mcg/day or placebo starting 7 days prior transplantion. We determined a baseline measurement of serum and urinary selenium. Subsequent measurements were made each week for a total of 28 days. Evaluations were made with validated SMAQ questionnaires which also included scales of mucositis severity, using the WHO mucositis scale. All of them performed by an observer blinded to what supplementation were being administered to each patient.

Results: We have recruited a total of 31 patients, of whom 16 were allogeneic and 15 autologous. We observed that 38.7% developed some degree of mucositis, most of them on the allogeneic arm (10 patients). Selenium consumption arm was associated with a median decrease of 32% (1.9 vs 2.8) in the WHO scale in the severity of mucositis compared to the placebo arm (p=0.046), however we didn't find difference in mucositis resolution time between groups (p=0.162). On the other hand, selenium supplementation was associated with shorter platelet engraftment time (p=0.041), without any significant difference in neutrophil engraftment time. With a follow up of 112 days, there are no difference about mortality or other analized variables.

Conclusions: Supplementation with selenium was associated with a slight decrease in the severity of mucositis in comparison with placebo. Without any relevant findings in relation to mortality or other variables analized.