Concern over new bowel cancer guidelines
New NHMRC guidelines that allow for considerably longer waits for colonoscopies in people suspected of colorectal cancer have been met with strong criticism from Bowel Cancer Australia.
The guidelines, published this month, say that for patients with symptoms suggestive of colorectal cancer, the total time from first presentation to diagnostic colonoscopy should be no more than 120 days. This is a significant change from previous guidelines, which recommended no more than 30 days after a positive FOBT test or visit to a GP with symptoms.
“We’ve got evidence to show that if you go beyond 30 days, you increase the risk, and if you run it out to 120 days, the cure rate will be lower,” says Bowel Cancer Australia’s Director, Associate Professor Graham Newstead, a Sydney-based colorectal surgeon.
He notes that if a cancer is caught early at the T1 stage, the cure rate is 98%.
“But if you wait until it’s a T2 cancer, the scale drops down and by the time you have metastasis you’re down to 40%.”
Dr Newstead says that the FOBT test is far from perfect and misses around 30% of cancers. He adds that while it’s understandable there aren’t resources for a colonoscopy-based national screening program, “if you’re going to use FOBT, then you simply can’t start extending the period of time to colonoscopy for people with a positive test”.
But the larger issue, he says, is that recommended times to colonoscopy are rarely met in Australia anyway.
“Around 90% of patients with positive FOBT wait between 116 to 181 days. It’s all very well to suddenly shift the goalposts and say 120 is OK, but 90% of patients are still somewhere equal to or beyond that date.”
The UK, with its overstretched National Health Service, still manages to do much better than Australia, Dr Newstead says, with over 90% of patients getting a colonoscopy after a positive FOBT test within a mandated 42 days.
Bowel Cancer Australia Chief Executive Julien Wiggins says that some people involved in developing guidelines have expressed concerns that the extended threshold de-emphasises the need for prompt evaluation.
“What is needed is a colonoscopy wait-time guarantee,” he says, “complete with public wait-time recording, reporting and adequate resourcing of colonoscopy.”
While the guideline authors say their new 120-day recommendation is evidence-based, Dr Newstead says two recent studies – one in Cancer Epidemiology, Biomarkers and Prevention, and another in Clinical Gastroenterology and Hepatology – go against the recommendation and support colonoscopy within 30 days of a positive FOBT.
He says he suspects the real reason for the change is a question of resource allocation and a desire to take some of the pressure off waiting lists.
Regardless of the increased risk, delaying colonoscopy adds considerably to the stress levels of already worried patients, he notes.
“Performing colonoscopy as promptly as possible minimises the risk of psychological harm in people experiencing symptoms or those with a positive screen awaiting investigation,” he says.
You can access the new guidelines here.