Opportunistic and Serious Infections in Patients with Neuroendocrine Tumors Treated with Everolimus: A Multicenter Study of Real-World Patients.

Introduction: The incidence of infections is poorly studied in patients with neuroendocrine tumors (NET) treated with everolimus outside of clinical trials. We aimed to evaluate the frequency of and risk factors for opportunistic infections (Opl) or any serious infection in eligible patients.

Methods: This was a retrospective multicenter study of a Latin American cohort of consecutive patients with advanced NET treated with everolimus. Duration of everolimus, comorbidities, Charlson comorbidity score, type of prior treatment, institution, and concurrent immunosuppressive conditions were tested for possible associations with serious (grade 3-5) infections in univariate and multivariable logistic regression models.

Results: One hundred eleven patients from 5 centers were included. The median duration of everolimus was 8.9 months. After a median follow-up of 32.9 months, 34 patients (30.6%; 95% CI 22.2-40.1) experienced infections of any grade, with 24 (21.6%; 95% CI 14.8-30.4) having a serious infection and 7 (6.3%; 95% CI 2.6-12.6) having at least 1 OpI (Candida sp., Toxoplasma gondi, Pneumocystis sp., Herpes sp., and Cryptococcus sp.). Four patients (3.6%) died from infections, but only 2 deaths (1.8%) were deemed to be related to everolimus. The multivariable analysis identified everolimus duration (every 6-month increase; OR = 1.28; 95% CI 1.02-1.60; p = 0.03) as an independent risk factor for serious infection.

Conclusion: Infections are more frequent in NET patients using everolimus than previously reported in clinical trials. Patients on everolimus should be closely monitored for infections, especially those receiving it for several months.