Data shows that people with inflammatory bowel disease that are treated with certain biologic and immunomodulatory therapies face increased risk for some cancers. The increased risk is also affected by the patient’s age, sex and other factors.
Counseling patients about the benefits of these therapies while discussing the relative risk for malignancies can help patients make informed educated treatment decisions.
Research has found that the greater risks appear to be for development of lymphoma, nonmelanoma skin cancer, or urinary tract cancers, depending on patient demographics and the agent prescribed. Some published reports also point to an increase in cervical malignancies, although the evidence so far remains mixed.
A transplant-like lymphoma is the most common form of lymphoma that develops in patients with inflammatory bowel disease treated with thiopurine. The rate of lymphoma is as high as 1 in 1000 patient years. Postmononucleosis lymphoma is less common but just as worrisome this form tends to affect men, especially those younger than 35 years old. Hepatosplenic T-cell lymphoma also tends to strike younger men. It tends to develop after at least 2 years of therapy with a combination of thiopurine and anti-tumor necrosis factor treatment or thiopurines alone.
Patients with inflammatory bowel disease that are treated with thiopurines are almost three times more likely to contract urinary tract cancers that those not treated with thiopurines.
Immune suppression with inflammatory bowel disease is a potential risk factor for cervical cancer. However, there are mixed findings and a lot of inconsistencies. Fortunately, cervical cancer is a disease with a great screening tool available, a Pap test.
Malignacies are a common conecern for both doctors and patients. It is important for all those involved to understand the risks. However, in absolute terms, they are small.
The risks do not appear the same for all people with inflammatory bowel disease. There has been a trend in physicians starting to risk-stratify patients by age and sex.