Risk of pneumonitis with mammalian target of rapamycin (mTOR) inhibitors everolimus and temsirolimus.

e13573 Background: Pneumonitis is associated with the use of mTOR inhibitors, everolimus and temsirolimus, which have been used widely in cancer therapeutics and clinical trials. Currently, the overall risk of pneumonits in patients treated with mTOR inhibitors has not been defined. We performed a systematic review and meta-analysis of published clinical trials to assess the risk of pneumonitis in cancer patients treated with mTOR inhibitors. Methods: Databases from PUBMED, the Web of Science, and abstracts presented at the American Society of Clinical Oncology conferences until May 2012 were searched to identify relevant studies. Eligible studies included prospective clinical trials in which patients received treatment with everolimus or temsirolimus as a single agent or in combination with other agents. Summary incidence, relative risk (RR), and 95% confidence interval (CI) were calculated employing a fixed- or random-effects model based upon the heterogeneity of the included studies. Results: A total of 2,303 patients with a variety of tumors from 18 studies (everolimus: 12, temsirolimus: 6) were included for the analysis. The overall incidences of all-grade and high-grade pneumonitis with mTOR inhibitors were 6.5% (95% CI: 3.7-11.1%) and 2.5% (95% CI 1.2-5.4%) respectively. The risk of all-grade pneumonitis did not vary significantly with tumor types (P=0.079), but vary significantly with their combination with other agents (P<0.001). There was no significant difference between everolimus and temsirolimus in the incidence of all-grade (P=0.22) and high-grade (P=0.28) pneumonitis. In comparison with controls, mTOR inhibitors significantly increased the risk of all-grade (RR=5.2, 95% CI: 2.09-12.93, P<0.001) but not high-grade pneumonits (RR=2.63, 95% CI: 0.66-10.40, P=0.41). Conclusions: The risk of pneumonitis is increased in cancer patients receiving mTOR inhibitors without significant difference between everolimus and temsirolimus.