Individuals with Barrett’s esophagus demonstrated significantly increased risk for colon polyps, according to results of a case-control study.
Results showed those with Barrett’s esophagus were 80% more likely to have any type of polyp detected during colonoscopy and 50% more likely to have adenomas detected.
“This association might have important implications,” Arthi Kumaravel, MD, of the Center of Excellence for Barrett’s Esophagus at Cleveland Clinic, and colleagues wrote. “Further studies are needed to determine the appropriate screening and surveillance colonoscopy intervals for patients with Barrett’s esophagus.”
A paper published in 1985 suggested an association between Barrett’s esophagus and colorectal cancer. Since then, studies have yielded conflicting results. The small sample sizes in some studies and the lack of true control groups in others made the findings difficult to interpret, Kumaravel and colleagues wrote.
The current analysis included 519 participants (75% men). Of them, 173 (age range, 50 to 75 years) had biopsy-proven Barrett’s esophagus and underwent colonoscopy at Cleveland Clinic between January 2002 and December 2011. The 346 controls, matched for age and sex, underwent colonoscopy and also endoscopy during the same time period and had no evidence of Barrett’s esophagus.
Individuals with a family or personal prior history of colon cancer or polyps, inflammatory bowel disease or familiar polyposis syndromes were excluded, as were those who underwent prior colonic resection.
Patients’ mean age at first colonoscopy was 61 years.
A higher percentage of those with Barrett’s esophagus were found to have polyps during index colonoscopy (45% vs. 32%; P=.003).
During follow-up, patients underwent one to five colonoscopies. Results of multivariate analysis — adjusted for age, sex and diabetes diagnosis — showed individuals with Barrett’s esophagus were significantly more likely to have colorectal cancer (HR=1.6%; 95% CI, 1.1-2.3) detected during colonoscopy. They also were more likely to have any type of polyp (HR=1.8; 95% CI, 1.3-2.6) and any adenoma (HR=1.5%; 95% CI, 1-2.1) detected.
“There have been several potential explanations for the association between Barrett’s esophagus and colon polyps or colorectal cancer, but the underlying mechanisms responsible for the higher prevalence of colon polyps in Barrett’s esophagus patients are not clearly understood,” Kumaravel and colleagues wrote.
Patients with Barrett’s esophagus may have similar environmental risk factors that are associated with colorectal cancer development, such as obesity, smoking history, alcohol consumption, age and gender.
“The genetic pathways leading to colon cancer have been well elucidated; however, the genetic alterations associated with development of Barrett’s esophagus and its progression to esophageal adenocarcinoma are not well defined,” the researchers wrote. “Certain mutations in the colon adenoma-to-carcinoma pathway, such as mutations to the APC gene and activation of the Src gene, have also been described in Barrett’s esophagus … Other genetic aberrations associated with cancer progression described in both conditions include p53 mutations, as well as allelic loss of chromosomes 17p and 18q. However, these genetic abnormalities have been reported in other cancers, too.”
Disclosure: The researchers report no relevant financial disclosures.