Overall cancer risk is slightly increased in patients older than 40 years within their first year of a celiac disease diagnosis, but the risk drops within a year of diagnosis, shows a Swedish study of 47,000 people with celiac disease.
“Celiac disease is associated with an increased risk of types of cancer, and we believe that this is due to the longstanding inflammation that is induced by gluten,” said first author Benjamin Lebwohl, MD, director of clinical research at the Columbia University Celiac Disease Center in New York.
Writing in Clinical Gastroenterology and Hepatology, the authors explained that most studies investigating cancer risk in patients with celiac disease were done before both the widespread use of serologic testing for celiac disease and access to gluten-free food was widely available. Earlier studies linked celiac disease to gastrointestinal malignancies, such as small intestinal adenocarcinoma, and lymphomas.
A prior analysis of this Swedish cohort found that the risk of small intestinal adenocarcinoma, while low, continued for up to 10 years after diagnosis with celiac disease. In the study, which was published in Gastroenterology, the authors found the risks of small-bowel adenocarcinoma and adenomas were significantly increased in people with celiac disease, compared with those without this disease.
“We have known from prior studies that people with celiac disease are at increased risk of developing certain cancers, but there has been limited study of this risk in celiac disease in the 21st century, where there is increased recognition (leading to more prompt diagnosis) and increased access to gluten-free food options (which may allow for more effective treatment),” said Dr. Lebwohl, who is also the director of quality improvement in the division of digestive and liver diseases at Columbia University. “We aimed to determine whether there is still an increased risk of cancer in this modern era, and we found that there still is an increased risk, but this increase is small and that it diminishes beyond the first year after the diagnosis of celiac disease.”
This nationwide cohort study in Sweden included 47,241 patients with celiac disease (62% female; mean age, 24 years), of which 64% were diagnosed since 2000. Each patient was age and sex matched to up to five controls. After a median follow-up of 11.5 years, a 1.11-fold increased risk of cancer overall was found in patients with celiac disease, compared with controls. The respective incidences of cancer were 6.5 and 5.7 per 1,000 person-years, and most of the excess risk was caused by gastrointestinal and hematologic cancer.
The overall risk of cancer was increased in the first year after celiac disease diagnosis (HR, 2.47; 95% CI, 2.22-2.74) but not afterwards (HR, 1.01; 95% CI, 0.97-1.05).
“It appears that the increased risk of cancer in people with celiac disease decreased over time, and this may be related to the beneficial effect of the gluten-free diet in the long term,” Dr. Lebwohl said.
The authors suggest that cancer risk, followed by a decline to no risk, may alternatively be due to the increased monitoring and medical examinations among patients with celiac disease. Also, symptoms of cancer, such as weight loss, may lead to broad testing that identifies celiac disease, the authors wrote.
For cancer subtypes, the strongest association between celiac disease and cancer was found for hematologic, lymphoproliferative and gastrointestinal cancers. Among gastrointestinal cancer subtypes, elevated risks were found for hepatobiliary and pancreatic cancer, but not for gastric or colorectal cancer. The cancer risk in celiac disease decreased in breast and lung cancer, which the authors suggested may be attributed to lower body mass index and smoking rates, respectively, observed in individuals with celiac disease.