P08.60 Primary Procarbazine, Lomustine, and Vincristine (PCV) chemotherapy (CT) in grade II/III 1p19q co-deleted gliomas: The Royal Marsden experience

Abstract

Background: Molecular markers are recognized as having significant prognostic and predictive value in primary brain tumours. 1p/19q co‐deletion has been identified as both a prognostic and predictive factor in oligodendrogliomas. The «standard» treatment (tx) for patients with high risk grade II/III oligodendrogliomas remains controversial, and is a question of an ongoing randomised multi‐centre clinical trial. Given the reported longterm neuro‐toxicities associated with primary RT, the prospect of omitting first‐line radiotherapy and using upfront chemotherapy (CT) is attractive, particularly for patients with favourable long term prognosis. Methods: Retrospective data were collected on clinical tx and tumor characteristics on pts with grade II/III 1p/19q co‐deleted oligodendrogliomas diagnosed between 01/2006 and 11/2016, referred to the Royal Marsden Hospital, whose primary non‐surgical tx was 6 cycles of PCV CT. Survival analyses were performed using the Kaplan‐Meier method. Statistical analysis was performed using SPSS 22. Results: 23pts were identified who were treated with upfront PCV CT as first line non‐surgical oncological treatment. Median ECOG PS at start of treatment was 1, median age 37 years (range 20‐54); 14pts (60.89%) were men. 8pts (34.8%) had anaplastic oligodendroglioma, 10pts (43.48%) had grade II oligodendroglioma, 3pts (13%) had anaplastic oligoastrocytoma, 2pts had grade II oligoastrocytoma. 19pts had previous debulking surgery and 4pts had biopsy only. 5 pts died due to disease progression. 15pts (65%) had grade 3/4 PCV‐related toxicities; 14 related to myelosuppression, 1 related to liver enzyme dysfunction. 8pts had tx delays. Median number of cycles received was 6 (range 2‐6). There were no PCV‐related deaths. Median survival was not reached after a mean follow up of 8.75 years [range 2.92 ‐ 17.6years]. 19 pts were alive at the time of mean follow up of 8.75 years. Mean survival was 14.6 years 95% CI (145.84 ‐ 201.21). Median progression‐free survival was 12.4 years (95% CI 73.72‐224.28). Conclusions: In this cohort of grade II/III 1p/19q co‐deleted oligodendroglioma pts, who received primary non‐surgical tx with PCV alone, such treatment was associated with long‐term survival, similar to outcomes reported for patients receiving combined modality treatment. Timely delivery of PCV CT was frequently limited by myelo suppression. Our data confirm that the current ongoing randomized phase III clinical trial ‐ which is addressing this tx paradigm ‐ is highly clinically relevant.