***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: One new included study as well as further participants to a study already included was added to this update involving a further 39 participants. There were a total of three studies included involving 162 participants for this update. For this review two RCTs were included investigating secondary lymphoedema in 60 women after breast cancer surgery and 20 men and women after head and neck cancer surgery. One ongoing trial with preliminary results of 82 participants was also identified studying radiotherapy induced diarrhoea as a secondary outcome. All studies had considerable drawbacks with regards to quality and reporting. One study on secondary lymphoedema reported a decreased number of recurrent erysipela infections in the selenium supplementation group compared to placebo. The second study reported a decreased facial swelling in the selenium group in a two-week period following surgical tumour resection. However, results must be interpreted with caution and cannot be generalised to other populations. The ongoing trial on radiotherapy associated diarrhoea preliminarily reported a lower incidence of diarrhoea in participants receiving selenium supplementation concomitant to pelvic radiation, however, no data were presented. We must await publication of final results to discuss these findings in detail. No RCTs were found studying the effect of selenium supplementation on other therapy-associated toxicities or quality of life/performance status in cancer patients. There is insufficient evidence at present that selenium supplementation alleviates the side effects of tumour specific chemotherapy or radiotherapy treatments or that it improves the after-effects of surgery, or improves quality-of-life in cancer patients or reduces secondary lymphoedema. To date, research findings do not provide a basis for any recommendation in favour or against selenium supplementation in cancer patients. Potential hazards of supplementing a trace mineral should be kept in mind. Since the last version of this review, the one new additional study has not provided information to change the conclusions of the original review.
Output:

This systematic review looked at studies providing selenium supplements to cancer patients and found no clear evidence that selenium supplements improve side effects of cancer therapy. No adverse effects were reported in the studies, but evidence of overdosing, all be it unintentional and selenium intoxication has occurred in several selenium users. More research is needed to find out which doses of selenium supplements can be reasonably used by cancer patients and whether selenium supplements can affect the side effects of cancer therapy.