Intracystic interferon-alpha in pediatric craniopharyngioma patients: an international multicenter assessment on behalf of SIOPE and ISPN

Intracystic interferon-alpha in pediatric craniopharyngioma patients: an international multicenter assessment on behalf of SIOPE and ISPN
Craniopharyngioma is a hypothalamic tumor in children with difficult treatment due to the location of this tumor given the neurologic, endocrine, metabolic and optic complications that can arise from surgery or radiation. Given that most craniopharyngiomas in children are cystic, and the epithelial cells share their origin with squamous epithelium, intracystic interferon (IFN) has been used. Institutional reports have previously been published demonstrating some promise of activity, but this is the first international cohort published. The report describes efficacy with delay or prevention of progression and need for definitive therapy (radiation/surgery), as well as toxicity and clinical outcome.
Patients from SIOPE and ISPN from 0-18 years of age with histologically proven or radiologically suspected craniopharyngioma who were treated with intracystic IFN alpha were included for the study.
Fifty-six patients from 21 centers were included. Twenty-two patients had purely or predominantly cystic lesions.
Intracystic IFN was first line therapy in 13 patients, with remaining patients treated with cyst fenestration/aspiration, surgical excision, radiation or radioisotope therapy upfront. Seventeen patients had been treated with radiation prior to intracystic IFN with median time to progression 2 years (range 0.3-9 years).
Median follow up after IFN therapy was 2.7 years. Five patients died (2 from tumor progression, 1 from endocrinopathy induced electrolyte imbalance and 2 from unrelated infections). IFN seemed to delay time to progression compared to each child's previous treatment. Further review revealed that delay was seen only in the group with predominantly cystic lesions, compared to those solid/cystic lesions. Forty-two patients had disease progression following IFN, median time 14 months (range 0-8 years). Twenty-three patients had no adverse side effects.
This is a retrospective study with limited patient numbers. Most patients had been previously treated and different regimens and number of cycles of intracystic IFN were used across different centers. The use of interferon was based on physician and patient preference. This is largely descriptive and it is difficult to make definitive conclusions based on this data.
Intracystic IFN remains a promising agent, and this study shows a prolonged PFS in predominantly cystic lesions compared to previous treatments with less morbidity than current standard therapy.