Success rate and myeloid toxicity of carboplatin desensitization protocol in low grade glioma patients

Abstract

20012 The effectiveness of carboplatin and vincristine chemotherapy in the treatment of low grade glial tumors is well established. This study was retrospectively designed to investigate the success rate and myeloid toxicity of carboplatin desensitization in a group of patients with carboplatin allergy. A total of 45 patients followed between October 1998-January 2007 with low grade glial tumors were included into study. Patients with severe hypersensitivity reactions (including anaphylaxis) were given 6-step desensitization protocol with gradual increase in concentration of carboplatin over 6 hours. Weekly absolute neutrophil count (ANC) and number of febrile neutropenia episodes of each patient during treatment period were collected from patient files. Among 45 patients, eight were switched to desensitization protocol. They had received a median of 6 courses (range 1–29) of carboplatin before developing their first allergic reaction. A median number of 15 courses of desensitizations (range 3–40) were given to these patients. Desensitization was successful in 6 patients. Age, gender, diagnosis were found to be similar in patients with and without carboplatin allergy. Regarding myeloid toxicity, mean percentage of follow-up weeks with ANC values below 1,500/mm3 in patients with and without desensitization were 0.42±0.04 and 0.21±0.02, respectively (p=0.009). Mean percentage of weeks with ANC values below 500/mm3 were not significant between two groups (p=0.28). However, desensitization protocol was not found to have an impact on number and presence of febrile neutropenia episodes. In conclusion, desensitization protocol might be an alternative to complete scheduled treatment in low grade glioma patients with hypersensitivity to carboplatin. Although, the percentage of low ANC weeks seemed to be statistically higher, insignificance of febrile neutopenia episodes in our patients demonstrated safety of desensitization protocol in terms of myeloid toxicity. No significant financial relationships to disclose.