Fears colon cancers could be missed in young patients
Younger patients with incidentally detected adenomas present a growing problem for colonoscopic surveillance, an expert has warned, amid concerns about the potential rise of young-onset colorectal cancer (CRC).
Associate Professor Alan Moss, Director of Endoscopy at Western Health, Victoria, said there was a lack of data on what transpires over time for average risk patients too young for bowel cancer screening programs (age <50) who had incidental colorectal adenomas detected and removed.
“The classic cases are a 35-year old woman with abdominal discomfort, bloating, altered bowel habit and iron deficiency in whom a colonoscopy reveals no sign of colitis nor malignancy but does detect incidental polyps; or a 40-year-old man with rectal bleeding and altered bowel habit in whom colonoscopy identified haemorrhoids as the cause of bleeding as well as incidental polyps,” he told doctorportal.
“These adenomatous polyps are removed at colonoscopy, but then we don’t know whether these patients are at the same risk of interval colorectal cancer as older patients, or whether their young age at presentation means they’ve got a significantly stronger predisposition to colonic polyp formation and greater potential for more rapid progression to colorectal cancer,” he said.
As a result, there was uncertainty about the ideal timing for subsequent surveillance colonoscopies to avoid interval colorectal cancer.
Associate Professor Moss said: “We don’t want to over-scope patients, but we also don’t want to miss the boat in these younger patients.”
Study finds that endoscopists prefer more intensive surveillance
Associate Professor Moss was commenting following the publication of his editorial in Gastrointestinal Endoscopy regarding a US study that found significant variation in endoscopists’ surveillance decisions for young patients with sporadic incidentally detected colorectal adenomas.
The study at a single US hospital focused on 141 patients under the age of 40 who had no known propensity for CRC before neoplastic polyps were discovered at an index colonoscopy.
While there was significant variation in endoscopists’ recommendations, in most cases endoscopists recommended repeat colonoscopy in three to five years. This was consistent with the recommendations of the main US colonoscopy surveillance guidelines, known as the US Multi-Society Task Force (MSTF) on colorectal cancer, which have been validated for patients over the age of 50.
However, when endoscopists in the study varied from the MSTF guidelines, it was to recommend a more aggressive surveillance strategy. The study showed that for patients with findings of high-risk, non-polypoid and serrated neoplasia, endoscopists regularly recommended shorter surveillance intervals than the MSTF guidelines propose for these polyps.
Young patients may under-estimate risk
Strikingly, the study also found that few young patients (24.7%) were compliant with their doctor’s repeat colonoscopy recommendations.
Associate Professor Moss commented in his editorial that younger patients might not appreciate their potential risk of developing colorectal cancer, as the compliance rates were substantially lower than shown for older patients in other research.
“It draws attention to the need for endoscopists to work particularly hard to educate young patients about the adenoma-to-carcinoma sequence, the important role of colonoscopy and polypectomy in altering the natural history of CRC, and the importance of adhering to surveillance recommendations,” he wrote.
The time was ripe for well-designed, multicentre, long-term follow-up studies of younger patients with adenomas, he argued.
In the meantime, he suggested Australian doctors adhere to the Cancer Council of Australia Colonoscopy Surveillance Guidelines.
Individual cases must be considered carefully, paying particular attention to cases of multiple polyps or advanced polyps, Associate Professor Moss wrote.
“In our own colonoscopy practice, we are increasingly being referred young patients for EMR (endoscopic mucosal resection) of an incidentally detected large sessile serrated adenoma/polyp,” he wrote.
“These young patients usually have no relevant family history and they do not meet the criteria for serrated polyposis syndrome at that stage. However with further surveillance colonoscopies over subsequent years, some experience sufficient serrated polyps in size and number to meet the diagnostic criteria for Serrated Polyposis Syndrome.”
Young-onset colorectal cancer rising?
The American Cancer Society (ACS) this year updated guidelines for those at average risk of bowel cancer to begin screening from age 45 (previously age 50).
It came on the back of a major analysis which showed people born in 1990 had double the risk of colon cancer and quadruple the risk of rectal cancer compared to those born in 1950.
However it is unclear whether the same trend is occurring in Australia. A study in the Medical Journal of Australia found the incidence of young-onset colorectal cancer did not increase in NSW during 2001–2008, although cases in younger patients tended to be more advanced at presentation than cases in older patients.
Dr Karen Barclay, Senior Lecturer in Surgery at the University of Melbourne is the author of the Cancer Council Australia’s algorithm on Colonoscopic Surveillance of Adenomas. She said the tool – which recommends colonoscopy at 5 years for low risk cases, and 3 years for high-risk cases – should be used for patients of all ages.
“There needs to be an appropriate reason for recommendation of earlier surveillance as colonoscopy has risk and financial cost to the patient and the system. Younger patients are at risk of having a substantial number of colonoscopies over a lifetime if surveillance is too frequent and balance must be obtained,” Dr Barclay told doctor portal.
She added: “Clinicians advising young people should emphasise preventive strategies.”
Dr Barclay also directed doctors to national guidelines on managing patients with serrated polyposis syndrome. Colonoscopy every 1 to 3 years is recommended in this cohort.