Immunosuppression does not raise risk of overall, cancer mortality

Use of immunosuppressants does not appear to increase the incidence of all-cause and cancer mortality in patients with noninfectious ocular inflammatory disease (OID) over a median follow-up of 10 years, a recent study has shown.

A team of investigators performed a retrospective cohort study at OID subspecialty centres. They collected exposure and covariate data from clinic inception through 2010 and determined the overall and cancer-specific mortalities via National Death Index linkage.

Separate Cox models were constructed to assess overall and cancer mortality for each class of immunosuppressant and for each individual immunosuppressant compared with person-time unexposed to any immunosuppression.

Participants received, when clinically indicated, tumour necrosis factor (TNF) inhibitors (eg, infliximab, adalimumab, etanercept), antimetabolites (eg, methotrexate, mycophenolate mofetil, azathioprine), calcineurin inhibitors (cyclosporine), and alkylating agents (cyclophosphamide).

Overall, 15,938 patients were found to be at risk for mortality over 187,151 person-years of follow-up. A total of 1,970 deaths occurred, of which 435 were due to cancer.

The mortality risks of both patients exposed to immunosuppressants but free of systemic inflammatory disease (SIDs; standardized mortality ratio [SMR], 1.04, 95 percent confidence interval [CI], 0.95‒1.14) and those unexposed to such medications (SMR, 0.95, 95 percent CI, 0.90‒1.01) were comparable to that of the US population.

Likewise, patients exposed to TNF inhibitors, antimetabolites, calcineurin inhibitors, and alkylating agents were not at significantly greater risk of overall (adjusted hazard ratio [aHR], 0.88, 0.89, 0.90, 1.11, respectively) and cancer mortality (aHR, 1.25, 0.89, 0.86, 1.23, respectively) than those not exposed to any of these therapies.

“These results were stable in sensitivity analyses whether excluding or including patients with SID, across 0-, 3-, or 5-year lags, and across quartiles of immunosuppressant dose and duration,” according to the investigators.