P11.72.A Glioblastoma in elderly patients. Which is the best treatment option?

Abstract

Background Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor in adults, and it is associated with a poor prognosis in the elderly. The current standard of care for newly diagnosed GBM is maximal surgical resection, followed by radiotherapy plus concomitant and adjuvant temozolomide (TMZ). In elderly patients with GBM, short-courses of radiotherapy with TMZ are used. Material and Methods We performed a single-center retrospective analysis of elderly GBM patients treated from 2013 to 2020. The primary endpoint was to evaluate progression free survival (PFS) and overall survival (OS) according to treatment received (TMZ and standard radiotherapy (60 Gy over a period of 6 weeks) vs TMZ and short-course radiotherapy (40 Gy in 15 fractions)). Secondary endpoints were analysis of population demographics and major toxicities associated to treatment. Results Twenty-two patients were identified. The median age was 72 years (range 65- 80), 18 (85.7%) patients were in ECOG-PS 0-1, 12 (57.1%) were males and all patients had undergone partial or complete resection surgery. Eleven (52.4%) patients received TMZ and standard radiotherapy and 10 (47.6%) patients received TMZ and short-course radiotherapy. Three (14.3%) patients had complete remission, 11 (52.4%) patients had partial response, 2 (9.5%) patients presented stable disease and 5 (23.8%) patients had disease progression. Median OS was 9 months (95% CI, 3.6 to 14.4) with TMZ with standard radiotherapy and 8 months (95% CI, 1.8 to 14.2) with TMZ and short-course radiotherapy (p=0.322). Median PFS was 5 months (95% CI, 2.8 to 7.2) with TMZ with standard radiotherapy and 6 months (95% CI, 3.1 to 8.9) with TMZ and short-course radiotherapy (p=0.944). Most common toxicities were hematological, with 5 (23.8%) patients presented thrombocytopenia grade 2 or higher. Five (23.8%) patients presented grade 3/4 toxicities (2 (9.5%) patients presented thrombocytopenia grade 4, 1 (4.8%) patient presented thrombocytopenia grade 3, and 2 (9.5%) patients presented anemia grade 3. Conclusion The prognosis of GBM remains poor besides standard therapy. TMZ and short-course radiotherapy should be an option in elderly patients due to its non-inferiority. Elderly patients should undergo a careful geriatric evaluation before starting treatment.