Lemaitre M, et al. - This research was initiated in order to investigate the risk of lymphoma linked with thiopurines and anti-tumor necrosis factor (TNF) agents, used alone or in combination, for the management of inflammatory bowel disease (IBD). The thiopurine monotherapy or anti-TNF monotherapy illustrated a connection with a minor yet statistically prominent, increased risk of lymphoma compared with exposure to neither medication, among adults with IBD. This risk was disclosed to be higher with combination therapy than with each of these treatments used alone. The yielded data could inform decisions regarding the benefits and risks of therapy.

Methods

• This nationwide cohort study examined the French National Health Insurance databases.
• This trial enrolled patients aged 18 years or older identified with IBD.
• The candidates were included from January 1, 2009, through December 31, 2013, and followed up until December 31, 2015.
• Patients were categorized as being exposed to thiopurine monotherapy, anti-TNF monotherapy, or combination therapy, or being unexposed, at each time of the follow-up.
• Incident lymphoma was included as the main outcome measure.

Results

• Among the 189,289 enrollees (54% women; median age, 43 years [interquartile range, 32-56 years]) and followed up for a median of 6.7 years, 123,069 were never exposed during follow-up, 50,405 were exposed to thiopurine monotherapy, 30,294 to anti-TNF monotherapy, and 14,229 to combination therapy.
• The data revealed 336 lymphoma cases: 220 in unexposed patients (incidence rate [IR] per 1000 person-years, 0.26; 95% CI, 0.23-0.29), 70 in patients exposed to thiopurine monotherapy (IR, 0.54; 95% CI, 0.41-0.67), 32 in patients exposed to anti-TNF monotherapy (IR, 0.41; 95% CI, 0.27-0.55), and 14 in patients exposed to combination therapy (IR, 0.95; 95% CI, 0.45-1.45).
• The multivariable Cox model disclosed higher risk of lymphoma among those exposed to thiopurine monotherapy (adjusted hazard ratio [aHR], 2.60; 95% CI, 1.96-3.44; P < .001), anti-TNF monotherapy (aHR, 2.41; 95% CI, 1.60-3.64; P < .001), or combination therapy (aHR, 6.11; 95% CI, 3.46-10.8; P < .001), compared with unexposed patients.
• A greater risk was illustrated in patients exposed to combination therapy vs those exposed to thiopurine monotherapy (aHR, 2.35; 95% CI, 1.31-4.22; P < .001) or anti-TNF monotherapy (aHR, 2.53; 95% CI, 1.35-4.77; P < .001).