Age 75 is probably still the best cut-off point for surveillance colonoscopy given the lead time for adenoma progression is similar to the remaining life expectancy of Australians at that age.

However Dr Cameron Bell told Australian Gastroenterology Week that one size did not fit all and there were other considerations such as co-morbidities that might influence decisions about who gets scoped.

Dr Bell, from the University of Sydney and Royal North Shore Hospital, said age does not alter the likelihood of detecting adenomas at surveillance colonoscopy.

“The pros of continuing surveillance if you really wanted to be an advocate for this, is that you will lower but not reduce completely the risk of patients dying from bowel cancer.”

“Against that is the potential harms of deleterious effects of prep, electrolyte disturbance, greater risks of sedation and anaesthesia in this age group, the potential increase in complexity of colonoscopy in older people, and management of complications.”

Dr Bell, who was awarded the GESA 2017 Distinguished Service Award at the meeting, said there was clear evidence that colonoscopy complications increased with age.

A US study of screening colonoscopy found the 30-day adverse event risk doubled in 75-79 year olds compared to 70-74 year olds. Screening reduced the risk of cancer in the younger group but the benefit was not seen effect in the older cohort.

“You have to consider the general health of the patients – whether they can tolerate that sequence of preparation and an invasive procedure.”

He acknowledged UK experts recommended colonoscopy should not be withheld in in over 75 year olds if they were ‘a fit and motivated person who has a tendency to produce multiple or advanced adenomas at follow up’.

Dr Bell said the number of colonoscopies in Australia each year would soon reach 1 million.

“Every 50-80 year old in Australia could already be scoped every eight years given the number of procedures that we do.”

However the sobering fact was that most people who developed bowel cancer had never had screening of any sort.

He concluded that the focus should always be on quality not quantity, and particularly in the elderly.

“You have to think about who did the previous colonoscopies and whether you trust their colon was rendered adenoma free last time they were scoped.”

Physicians should aspire to improving procedural quality and target the patients most likely to benefit.