Colorectal cancer risk with ulcerative colitis similar in Asia, Europe, N. America

Last Updated: 2017-03-16

By Scott Baltic

NEW YORK (Reuters Health) - The risk of colorectal cancer (CRC) in Asian patients with ulcerative colitis (UC) is similar to recent risk estimates from Europe and North America, even though sporadic CRC is much less common in Asian countries, according to a new meta-analysis.

The findings indicate a need for similar surveillance strategies, researchers conclude in a report online February 20 in The Lancet Gastroenterology and Hepatology.

Data pooled from 44 studies involving more than 31,000 UC patients in 14 Asian nations - from Israel and Turkey to China, Japan, and Malaysia - showed a total of 293 colorectal cancers and a CRC prevalence of 0.85%, with no significant geographical variations within the region.

At 10, 20 and 30 years, the cumulative risks of CRC in patients with UC were 0.02%, 4.8%, and 13.9%, respectively.

But while it appears that similar surveillance strategies are needed there, acceptance and cost of colonoscopies might be barriers, the researchers say, adding that further examination of non-invasive screening tools for CRC in patients from resource-poor settings is needed.

They also emphasized the potential need “to treat to mucosal healing to reduce the risk of colorectal cancer in those with long-standing ulcerative colitis.”

Dr. Sawan Bopanna, of the All India Institute of Medical Sciences, New Delhi, and coauthors point out that the incidence of CRC in Asia has been declining, both overall and in patients with UC. But UC incidence has been rising, and UC substantially increases CRC morbidity and mortality.

There may be several reasons for this decline, Dr. Bopanna told Reuters Health by email, including better therapies for UC and better adherence to screening guidelines.

In an editorial, Dr. Gilaad G. Kaplan of the University of Calgary, Alberta, Canada, suggests that ascertainment bias and other methodological challenges might affect cancer estimates in some Asian nations.

Still, he concluded, “The study highlights the importance of studying inflammatory bowel disease outcomes in Asia. This work also shows the universal risk of colon cancer in ulcerative colitis and, thus, gastroenterologists in Asia will need to implement robust dysplasia surveillance programs.”

This “important study” answers “a very reasonable question,” Dr. Jeffrey Meyerhardt, an American Society of Clinical Oncology expert in gastrointestinal cancers, told Reuters Health in a phone interview.

Given that UC predominates over other CRC risk factors, the study should help raise awareness among clinicians in Asia, predicted Dr. Meyerhardt, who is also the clinical director of Gastrointestinal Cancer Center at the Dana-Farber Cancer Institute, Boston.

SOURCE: http://bit.ly/2mOeKD0

Lancet Gastroenterol Hepatol 2017.