New Zealand (NZ) has high bowel cancer rates, which the Bowel Screening Programme aims to
reduce by early detection of bowel cancer and its precursor, adenomas (polyps). Bowel cancer
and adenoma rates are higher in countries like NZ with low intake of the essential trace
mineral selenium. Overseas, trials of selenium supplements reduced adenoma recurrence in
people with low blood selenium, but not with high levels (where adding selenium increased
health risks). Laboratory research explained this, and found certain types of selenium are
safer and more effective. The optimal type and dose of selenium to use in NZ cancer
prevention trials is not known.
The main objective of this trial is to evaluate which dose and type of selenium (either
selenomethionine or methylselenocysteine) gives optimal selenium status to maximise cancer
prevention without causing health problems from excessive selenium intake. We also want to
see how much selenium is needed according to selenium blood levels before starting selenium
in the trial. Side effects will be evaluated, as will recruitment rates.
This will determine the feasibility of developing a large randomised trial of selenium to
reduce the recurrence rates for advanced adenomas in NZ.
This trial will recruit 60 patients from Middlemore and Waikato Hospitals with an advanced
adenoma removed through the Bowel Screening Programme. Patients will take one selenium
compound, dosed at 50 mcg/day for 6 weeks then 100 mcg/day for 6 weeks, and will have blood
tests at baseline, then blood tests and evaluation of side effects at 6 weeks and 12 weeks.
Phase:
Phase 1
Details
Lead Sponsor:
University of Auckland, New Zealand
Collaborators:
Cancer Trials New Zealand Counties Manukau Health Waikato Hospital