SAN DIEGO – Elderly patients who never previously underwent screening colonoscopy have a high prevalence of colorectal cancer and could benefit from screening if they are healthy and functional and have a life expectancy of at least about 7 years, based on a review of colonoscopies done on people aged 76-85 at one U.S. center.
The results also showed a reasonable detection rate for colorectal cancers in the same age group when their prior colonoscopy had last been done 10 or more years before, Dr. Therese G. Kerwel said at the annual Digestive Disease Week meeting.
"The U.S. Preventive Services Task Force says that you don’t see benefit [from screening colonoscopy] until about 7 years so that’s the benchmark. If you think the person will live for another 7 or more years, then screen. If not, then it’s not worth the resources," said Dr. Kerwel, a surgeon at Spectrum Health in Grand Rapids, Mich.
"The headline from the U.S. Preventive Services Task Force is to stop screening at age 75; that’s what everyone knows. A lot of people don’t read the fine print, the loophole that you can screen elderly people if they are healthy and functional," Dr. Kerwel said in an interview.
Another reason to strongly consider screening elderly patients who are healthy enough to potentially benefit is that if they develop colorectal cancer, they have an increased risk for an emergency presentation compared with younger adults, with the potential to develop bleeding, obstruction, or perforation, she said.
"It’s always a balance of risk and benefit, but there is definitely a subset of the elderly who need to be focused on a little more."
The review also showed a sizeable percent of elderly people underwent colonoscopy at Spectrum Health roughly 5 years following a prior procedure, with no cases of colorectal cancer detected, indicating that a significant number of elderly people had been subjected to overly aggressive colonoscopy, Dr. Kerwel said.
She and her associates reviewed 903 people, aged 76-85 years, who underwent colonoscopy at Spectrum Health during January 2009 to December 2010. The colonoscopy occurred purely for screening in 19%, for surveillance in 42%, for symptoms in 35%, and for other reasons in 4%.
Fifty-three of the people had never previously undergone colonoscopy (in this subgroup roughly half the procedures were for screening and half were for symptoms). Colonoscopy identified colorectal carcinoma in 9%. An additional 56 people from the study group had not had a prior colonoscopy for at least 10 years; in this group the new procedure detected carcinoma in 5%.
The remaining 88% of the procedures reviewed occurred within 9 years or less of prior colonoscopy. The largest subgroup was 247 people (27% of the study group) examined 4-5 years after a prior colonoscopy. In this subgroup the procedure identified no carcinomas, and in everyone else examined 9 or fewer years after their prior examination, about 3% had cancers identified.
These results suggest that repeat colonoscopies at intervals shorter than 10 years may have questionable utility in the elderly, Dr. Kerwel said.
She said that she had no relevant financial disclosures.