Abstract LB064: Long-term application of TTFields in anaplastic astrocytoma - a case study

Abstract

Abstract Background: Anaplastic astrocytomas WHO III° (AA) represent diffusely infiltrating, high grade gliomas (HGG). Despite advancements in the molecular characterization of HGG treatment options are limited and are often in analogy to grade IV glioblastoma treatment. Tumor Treating Fields therapy (TTF) is an established modality for newly diagnosed and recurrent glioblastoma (GBM) shown to significantly improve progression-free and overall survival. While TTF is under investigation in grade III gliomas in several clinical trials, we present an exemplary case of an AA undergoing mid-term TTF therapy and adjuvant chemotherapy to explore treatment adherence, feasibility and safety. Methods: We present case details of a patient from our specialized neurosurgical oncology center, with an anaplastic astrocytoma (WHO grade III) who began TTF treatment at first diagnosis while being in the adjuvant chemotherapy phase at the time of TTF commencement. We describe treatment details and the course of disease under continuous and ongoing TTF therapy. Results: In December 2016 a 43year-old male patient was diagnosed with an anaplastic astrocytomaIDH 1/2 mutant, MGMT promoter-hypermethylation without 1p/19q codeletion. After biopsy and consequent partial tumor resection, he received concomitant radiochemotherapy and adjuvant chemotherapy with temozolomide. TTF was started six months after initial diagnosis. He has now completed 1328 days of treatment with an average daily usage of 90% and has survived 48 months from first diagnosis (cutoff January, 8th, 2021). Since beginning TTF, he has undergone temozolomide treatment for 6 cycles. He continues TTF without further adjuvant therapy. The patient is symptomatically stable and his quality of life is maintained. Significant adverse events or longer treatment interruptions have not occurred. Conclusion: The treatment with TTFields was well tolerated and seems to be feasible in this patient with an anaplastic astrocytoma. Considering the long treatment duration and favorable average daily usage, this treatment might be suitable for a long-term treatment in high grade gliomas. Ongoing clinical trials will provide more information on safety and efficacy for the use of TTFields in patients with grade III gliomas. Citation Format: Darko Markovic. Long-term application of TTFields in anaplastic astrocytoma - a case study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB064.