Analysis of data from a Swedish cancer registry shows a more than 5-fold increased risk of non-Hodgkin lymphoma in patients with celiac disease, but the risk is steadily decreasing, and is less than half of what it was 40 years ago.
Researchers at the( National Cancer Institute) in Bethesda, Maryland, and the Karolinska Institute in Sweden conducted a study of more than 60,000 patients with lymphomas diagnosed in Sweden between 1965 and 2004 who were matched with an individual with similar characteristic, but without lymphoma, the (controls).
Celiac disease is caused by an abnormal reaction of the immune system to gluten, a protein found in many grains, such as wheat, rye, and barley, and other foods. This results in damage to the small intestine and prevents the proper absorption of nutrients from food. Symptoms include chronic diarrhea and weight loss if exposed to gluten.
Dr. Ying Gao of the NCI and colleagues identified 37,869 cases of non-Hodgkin's lymphoma, 8,323 cases of Hodgkin's lymphoma, 13,842 cases of chronic lymphocytic leukemia. The investigators also recruited 236,408 matched controls and 613,961 first-degree relatives. Patients with a history of celiac disease were identified though hospital discharge data.
"Overall, we found persons with a hospital discharge diagnosis of celiac disease to have a 5.35-fold increased nonHodgkin's lymphoma risk," the team reports in the medical journal Gastroenterology. The risk of Hodgkin's lymphoma was "borderline increased" and there was no increased risk of chronic lymphocytic leukemia in celiac disease patients.
The risk of nonHodgkin's lymphoma in patients with celiac disease was increased 13.2-foldby between 1975-1984, 7.90-fold between 1985-1994, and 3.84-fold between 1995-2004.
Individuals with a sibling affected with celiac disease also had a 2.03-fold increased risk of nonHodgkin's lymphoma.
"At this time, we do not know what the actual cause of the link is," Gao told Reuters Health. "Prior studies have suggested that celiac disease leads to inflammation and that inflammation drives development of lymphomas."
"There are two key messages of our study," Gao said. "First, due to early detection of celiac disease, individuals with a diagnosis of celiac disease have a lower risk of developing lymphoma compared with the past, when celiac disease was detected at a more severe state and consequently, the risk of lymphomas was higher."
"Second, persons with a family history of celiac disease had a higher risk of developing lymphoma. This familial association was independent of a personal history of celiac disease. Taken together, these findings suggest that there might be some underlying mechanisms that lead to both celiac disease and lymphoma," Gao concluded.
SOURCE: Gastroenterology January 2009.