Crohn’s disease is associated with an increased risk for thyroid cancer, according to the results of a case-control study.
These two disorders could share common pathogenetic pathways, the researchers wrote.
“Our results show that thyroid cancer is more prevalent in patients with IBD than the control group, specifically [Crohn’s disease],” Bo Shen, MD, of the Center for Inflammatory Bowel Diseases, Digestive Disease and Surgery Institute, the Cleveland Clinic Foundation, and colleagues wrote. “[Crohn’s disease], not [ulcerative colitis], was found to be associated with a high frequency of thyroid cancer.”
Shen and colleagues — including Vaibhav Wadhwa, MD, of the department of internal medicine, Fairview Hospital, the Cleveland Clinic Foundation — used the 2012 National Inpatient Sample database to evaluate more than 28 million hospitalizations, 289,935 of which were IBD-related, and 315,145 of which were diverticulitis-related, who served as controls. They chose to use diverticulitis patients as controls instead of the general population based on their “hypothesis that IBD and thyroid cancer are both chronic, immune-mediated disorders and may share the same pathways.”
Univariable analysis showed patients with IBD had a significantly higher risk for thyroid cancer compared with diverticulitis patients (OR = 1.97; 95% CI, 1.5-2.6), with comparable prevalence between men and women.
After analyzing Crohn’s disease and ulcerative colitis patients separately, they found that Crohn’s patients had more than a twofold higher risk for thyroid cancer compared with diverticulitis patients (OR = 2.3; 95% CI, 1.73-3.09). Crohn’s patients also had a significantly higher risk for thyroid cancer compared with ulcerative colitis patients (OR = 1.8; 95% CI, 1.23-2.63), while ulcerative colitis patients had a comparable risk for thyroid cancer compared with diverticulitis patients.
Multivariable analysis adjusting for age, sex, ethnicity, Charlson comorbidity index, and hospital size, location and teaching status showed Crohn’s disease was associated with an increased risk for thyroid cancer compared with diverticulitis patients (OR = 2.3; 95% CI, 1.06-5.1), but not ulcerative colitis. In addition, age appeared to be protective against developing thyroid cancer (P < .005) and a higher Charlson comorbidity index was associated with an increased risk for thyroid cancer (OR = 1.5; 95% CI, 1.3-1.7).
The investigators also performed a secondary comparison in two other benign, nonchronic, nonimmune disorders to verify their results, and found that patients with IBD also had a higher prevalence of thyroid cancer compared with chronic constipation and atonic colon patients.
“To prove causation between IBD and thyroid cancer, analytical and prospective studies would be required,” they concluded. – by Adam Leitenberger
Disclosures: The researchers report no relevant financial disclosures.