Topical calcineurin inhibitors and risk of lymphoma: a systematic review and meta-analysis

The topical calcineurin inhibitors (TCIs) tacrolimus and pimecrolimus have been used widely as corticosteroid-sparing agents in treating various cutaneous diseases. However, the association between TCIs and risk of malignancy remains controversial. By systematic review and meta-analysis, we aimed to investigate the association between TCIs and lymphoma. Eligible studies in online databases were identified from the date of inception to August 30, 2020. To assess the outcome of TCI-related risk of lymphoma, analysis of cohort studies comparing the incidence of lymphoma with and without treatment with TCIs was performed. Furthermore, the subgroup analyses of Hodgkin lymphoma and non-Hodgkin lymphoma were also conducted. The pooled results revealed that using topical tacrolimus (RR 1.68, 95 % CI 1.39–2.04) or pimecrolimus (RR 1.40, 95 % CI 1.13–1.74) significantly increased the risk of lymphoma. TCI users also showed higher incidence of lymphoma in the range of 0.02–0.09 %, compared to that of 0.02–0.06 % in the control group. Additionally, subgroup analyses showed both tacrolimus (RR 1.89; 95 % CI 1.53–2.32) and pimecrolimus (RR 1.38; 95 % CI 1.09–1.74) had significantly higher risk of non-Hodgkin lymphoma, but no increased risk of Hodgkin lymphoma. In conclusion, TCI-exposed patients have a significantly increased risk of lymphoma, especially non-Hodgkin lymphoma.