Researchers have found that methylene blue dye taken in oral form could improve detection of harder-to-find growths (polyps) in the colon that can develop into bowel cancer.
A team of scientists at the Mayo Clinic in Jacksonville, led by Michael B. Wallace MD, professor of medicine and director of the digestive disease programme, carried out the research. They discovered that administering blue dye to a patient before a colonoscopy can increase adenoma (tumour) detection rates and could help in the more accurate detection of bowel cancer.
Colonoscopies are routinely used to screen for bowel cancer, but certain types of polyps – flat or subtle ones – are hard to detect and can sometimes be missed. Researchers at the Mayo Clinic conducted a double-blind parallel-group phase three trial involving more than 1,200 patients who were scheduled for colonoscopies at 20 locations around the world.
One group of patients was given a full dose of methylene blue dye in tablet form that they swallowed before the colonoscopy. The second group was given a placebo and a third group was given half a dose of methylene blue dye. In the past, some radiologists have used a catheter to spray blue dye into the colon but this was the first time that the dye has been given in tablet form.
Among patients who received the full dose of dye, detection rates of adenomas were 9% higher compared with the control group. In major trials, every 1% increase in detection rates corresponds to a 3% fall in incidence of bowel cancer and a 5% decline in cancer deaths. Consequently, a 9% increase in detection rates could mean significant numbers of lives saved.
In May last year, a new drug application was made to the FDA by Cosmo Pharmaceuticals for the methylene blue drug used in the trial. Work is currently underway to address unspecified “deficiencies” found by the FDA in relation to the drug which Cosmo Pharmaceuticals says it is endeavouring to resolve soon. Before long, it is hoped that the use of blue dye may become a routine part of colonoscopy screening.
Bowel cancer is the second biggest cancer killer in the UK, accounting for around 16,000 deaths a year.
Colonoscopies are routinely used to screen for disease, alongside Faecal Immunochemical Testing which are home tests sent to everyone over the age of 60 in England and Wales (50 in Scotland).
A colonoscopy can detect bowel cancer in the early stages, even before there may be any symptoms, identifying and removing polyps or adenomas, which can become cancerous over time. Anyone who has a positive FIT test will be referred for a colonoscopy.
Early detection is key
If you are experiencing any symptoms that might indicate bowel cancer (blood in your poo or rectal bleeding, a change in bowel habit that has lasted longer than four weeks or persistent abdominal discomfort), it is important to see a doctor.
Nine out of 10 people will survive bowel cancer if it is diagnosed at its earliest stage and colonoscopy remains the single most effective way of picking up the disease early.
Bowel cancer specialists | London
We are experts in identifying and treating colon cancer and would be happy to advise you if you are worried about your symptoms or would like to take a preventative approach to your healthcare, particularly if you have a family history of bowel cancer or polyps.