“The point I want to make is the lymphoma rates in the thiopurine monotherapy and anti-TNF monotherapy groups are not significantly different. So the claim that’s been out there that the increased lymphoma risk in IBD patients can be completely explained by thiopurines is wrong. This study is showing us that with anti-TNF monotherapy there is still a low-level risk of lymphoma,” Dr. Loftus said.
“It is somewhat eyebrow-raising when you see that relative risk of 6.1, and that’s what patients are going to focus on, but when you counsel patients you have to redirect them to the absolute risk. You can say, ‘Even on combination therapy, your risk is 1 in 1,000,’ ” the gastroenterologist said.
Dr. Sandborn said the lymphoma signal hadn’t been spotted previously because the individual registries of IBD patients on anti-TNF agents are too small to allow for identification of a small increase in risk. The French investigators overcame that limitation by tapping into the country’s national health care system.
“This is a huge dataset and I think the message is unequivocal,” Dr. Sandborn said.
