A 43-year old Caucasian woman presents to an outside gastroenterology clinic for evaluation of chronic diarrhea of unknown etiology. Overall, her symptoms included foul-smelling diarrhea occurring up to eight times per day, a pruritic rash found on her arms and legs, and an approximate 30-lb weight loss over the past year. Despite her best effort with over-the-counter options, she has not been able to attain symptomatic relief. Further laboratory testing and biopsy reveal iron deficiency anemia, multiple vitamin deficiencies, positive anti-tissue transglutaminase (tTG) antibodies, and increased intraepithelial lymphocytes and villous blunting. The diagnosis is confirmed as celiac disease, at which point the patient asks a slew of questions, including “Am I more likely to get cancer?”
While celiac disease has become a more frequently encountered diagnosis in inpatient and outpatient settings, one of the major concerns amongst both newly diagnosed and chronic celiac patients is the potential increased risk of cancer. Most of the population-based studies have shown that celiac disease poses up to a 30% increased risk of cancer, with the most common malignant diagnoses being lymphoma and GI cancers (including esophageal, hepatocellular, and colorectal). Interestingly, the same studies have shown a decreased risk of both breast and lung cancer, although the exact pathophysiology behind these findings have yet to be elucidated. Another interesting finding is that patients with celiac disease were found to have between a 35% and 39% increased mortality risk. This increased risk was all-cause and not just cancer-related; however it does prompt the need for additional studies focusing on mortality risks in celiac patients who develop cancer.
There is no formal consensus on how long patients with celiac disease are at increased risk for cancer, although one cohort study that included patients with up to 25 years of follow-up concluded that the increased risk for cancer was within the first 15 years after diagnosis after which only non-Hodgkins lymphoma remained elevated. Most of the population studies performed to date have also been outside of the United States, including the United Kingdom and Sweden. Populating a more robust US database assessing the risk for cancer in celiac patients could help identify additional trends in cancer potentially not yet seen in European studies.
One of the mainstays of treatment in celiac disease is a gluten-free diet. Unfortunately, there is a lack of data regarding the impact of compliance with diet and cancer risk. Interestingly, one European study showed that celiac patients compliant with a gluten-free diet still were at increased risk of lymphoma, although the corresponding risks of other cancers were not mentioned. More studies are obviously needed to further analyze this relationship, especially since it could have a profound impact on patient compliance with their diet.
Although there appears to be an association between celiac disease and an increased risk for cancer, additional data is needed to further delineate more specific risk factors in celiac patients. Until then, health care practitioners should be prepared to answer a celiac patient’s questions about their cancer risk.
Should patients with celiac disease have more aggressive cancer screening protocols, especially for those malignancies that appear to be the most common amongst currently available studies? Do celiac patients deserve a more routine and robust history and physical exam in attempts to identify signs and symptoms that may be associated with cancer? These are just some of the questions that we should be considering every time we encounter a patient with celiac disease. As we wait for additional studies to be completed, we should at least have a heightened awareness of the apparent cancer risk in these patients and continually reassess their need for a more thorough work-up.
Questions to Readers:
- What types of malignancies have you seen in patients with celiac disease?
- Do you have any observational experience regarding the association between compliance with gluten-free diet and diagnosis of cancer in celiac patients?