Colonoscopies: Major Study Reveals Inconvenient Procedure Doesn’t Reduce Risk of Cancer Deaths
Colonoscopy-based colon cancer screening may not save people from death, a large-scale study has suggested.
Gastroenterologists have for decades touted the inconvenient procedure, in which a small tube fitted with a camera passes through the anus into the intestines to check for problems in the gut.
But Norwegian researchers, who have assessed its benefits, now say the screening is not a ‘magic bullet’.
Offering colonoscopies to thousands of people theoretically only lowered diagnosis rates by a fifth.
And there was no significant difference in the number of fatalities, according to the 10-year study of more than 80,000 people aged 50 and 60.
Top experts said the real research, published in the prestigious New England Journal of Medicine, suggested that colonoscopies may not be “as good as we always thought.”
However, they argued that the procedure is still a valuable screening tool because it helps detect cancers that would otherwise go undetected.
A ‘landmark’ study has suggested that colonoscopies may not be the ‘magic bullet’ they once thought
But the detection rates were comparable to the results of home tests, which are sent to people aged 60 to 74 in the UK.
Colonoscopies are only provided to Britons on the NHS if their samples reveal blood in their stool.
In contrast, the US Preventive Services Task Force recommends all adults ages 45 to 75 have a colonoscopy every decade. There are also other screening options available, such as stool tests.
Closer analysis showed that colonoscopies had a much more pronounced effect on cases and deaths in the fraction of people who actually turned up for a test.
Many people are put off by the invasiveness of the test.
Colonoscopies can help detect small precancerous growths that can then be excised before they become a tumor.
This helps prevent the cancer from ever developing and reduces the need for more invasive treatments such as surgery, radiotherapy, and chemotherapy later on.
There are about 43,000 new cases of colon cancer in the UK and 106,000 in the US each year.
Rates have skyrocketed in recent decades, with experts blaming diets high in processed and red meat.
The first randomized trial of its kind tracked the health data of 85,585 people from Poland, Norway, Sweden and the Netherlands.
It was led by Professor Michael Bretthauer, a gastroenterologist at Oslo University Hospital.
The participants were between the ages of 55 and 64 when the study began.
About 28,220 were invited for a one-time colonoscopy screening, of which about 40 percent accepted the offer.
The others did not undergo the screening because it was not recommended as standard practice in their countries.
After an average follow-up of 10 years, there were 259 cases of colon cancer in the screening group compared to 622 in the other cohort.
Statistical analysis suggested that colonoscopies only reduced disease rates by about 18 percent.
Professor Bretthauer said, ‘It’s not the magic bullet we thought it was. I think we oversold colonoscopy.’
dr. Samir Gupta, a gastroenterologist at the University of California, San Diego, who was not involved in the study, told Stat: “This is a landmark study.
“I think we all expected colonoscopy to do better. Maybe colonoscopy isn’t as good as we used to think.”
dr. Jason Dominitz, a gastroenterologist with the Veterans Health Administration, said a planned 15-year follow-up study would likely have a greater effect on deaths.
He added, “I don’t think anyone should have to cancel their colonoscopy.”