223Use of Anti-TNFs in Patients with a Prior History
of Malignancy
The safety of anti-TNF therapy in patients with a history of a prior malignancy is
important given the chronic nature of IBD. In a retrospective cohort of 333 IBD
patients who developed cancer and then subsequently were treated with anti-TNF
agents, exposure to an anti-TNF agent or an antimetabolite after cancer was not
associated with an increased risk of incident cancer, as compared to those who did
not receive immunosuppression [ 46 ]. In a subsequent meta-analysis, Shelton et al.
also found a reassuring lack of increased recurrence rate associated with anti-TNF
use. The authors included 16 studies (10 published, 1 unpublished, and 5 abstracts)
looking at 11,702 patients with a history of prior cancer diagnosis who also had RA
(9 studies), IBD (8 studies), or psoriasis (1). In the group of patients on no immuno-
suppression, there were 609 new or recurrent cancers over 12,404 person-years
(p-y) of follow-up evaluation, yielding a pooled incidence rate of 37.5 per 1000 p-y
(95% CI, 20.2–54.7). Data were significantly heterogeneous with incidence rates
ranging from 0 to 62.5 per 1000 p-y. Patients who were subsequently placed on anti-
TNF therapy or immunosuppression had a median interval of 6 years to introduction
of immunosuppression. The 1753 subjects contributing 5842 p-y of follow-up were
exposed to anti-TNF therapy after prior cancer. There were 215 cases of new or
recurrent cancer, which gave a pooled incidence rate of 33.8 per 1000 p-y (95% CI,
22.3–45.2). This was similar to what was observed in the no immunosuppression
group. There was also no significant difference between the anti-TNF group and the
group of patients treated with conventional immunosuppressants. A total of three of
the studies looked at combination therapy with anti-TNF + immunomodulator, and
the pooled incidence rate was 54.5 per 1000 p-y (95% CI, 29.7–79.3). This was not
statistically different than the results of analysis of individual therapy with anti-TNF
(p = 0.23), other immunosuppression (p = 0.27), or no immunosuppression
(p = 0.47) [ 47 ]. This body of information suggests clinicians may cautiously select
appropriate patients with a history of prior malignancy for treatment with anti-TNF
therapies.
How to Discuss the Risks and Benefits of Anti-TNFs
When considering treatment options for patients with CD and UC, it is imperative
to effectively communicate both the risks and benefits of potential medical thera-
pies to patients. Risk communication can be misunderstood, and thus patients
may be less amenable to initiating therapies that would be effective at treating
their underlying IBD. The communication of the risks of malignancy versus the
potential treatment benefits from anti-TNF agents can dramatically influence a
patient’s ultimate decision. “Rare” means different things to different people, and
the way “rare” is portrayed by a clinician can dramatically influence a patient’s
13 Tumor Necrosis Factor-Alpha Inhibitors and Risks of Malignancy