Incidence, management, and outcomes of procarbazine-associated hypersensitivity reactions in patients receiving PCV for lower-grade gliomas.

Background: The use of procarbazine in the treatment of lower-grade gliomas as part of the procarbazine, lomustine, and vincristine (PCV) regimen is frequently limited by the development of hypersensitivity reactions (HSRs), which often require dose reduction or cessation of procarbazine therapy prior to the completion of a planned treatment course. The incidence, clinical characteristics, and potential predictors of these reactions are not well defined. Methods: We conducted a retrospective cohort study of patients with lower-grade gliomas who received PCV between January 2016 and January 2024 at a tertiary medical center. Data on patient demographics, tumor type, clinical characteristics, treatment course, and HSRs were collected. A total of 61 patients were included. Results: The overall incidence of procarbazine-associated HSRs was 60.7% (95% CI: 48.4%-72.9%). All HSRs involved the development of rash, with 86.5% being pruritic and 21.6% involving the face. Treatments for HSRs included antihistamines (62.2%), topical corticosteroids (35.1%), and systemic corticosteroids (27.0%). Patients who experienced procarbazine-associated HSRs received significantly fewer cycles of procarbazine compared to those who did not experience HSRs ( Conclusions: The high incidence of HSRs in this population, including cases of suspected anaphylaxis, should be considered carefully by clinicians when prescribing chemotherapy for glioma and warrants routine counseling and close monitoring.