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LTBK-12. EORTC 26951, RANDOMIZED STUDY OF ADJUVANT PCV AFTER 59.4 GY RADIOTHERAPY: VERY LONG TERM FOLLOW-UP


 
 
 Between 1995 and 2002 the EORTC Brain Tumor Group conducted a prospective phase III study on adjuvant procarbazine, CCNU and vincristine (PCV) chemotherapy in anaplastic oligodendroglioma (AOD). A mature follow-up presented in 2012 showed survival benefit of the addition of PCV, in particular in 1p/19q co-deleted tumors and tumors with MGMT promoter methylation. We now present very long term follow-up.
 
 
 
 Patients were eligible if locally diagnosed with a newly diagnosed AOD. They were randomized between radiotherapy (RT, 33 x 1.8 Gy) and the same RT followed by 6 cycles PCV (RT/PCV). Primary endpoints were overall survival (OS) and progression free survival (PFS). 1p/19q status (FISH) was determined in 300 patient. Kaplan- Meier technique and Cox modeling were used for long term survival analysis. Primary analyses were adjusted for known prognostic factors. For other analyses no adjustment was performed.
 
 
 
 With 368 patients included, a median follow-up of 18.4 years and 307 (83%) survival events, median and 20-year survival after RT/PCV versus RT alone were 42.3 mo and 16.8% vs 30.6 months and 10.1% (HR 0.78; 95% CI (0.63, 0.98), adjusted p=0.06). Eighty patients were 1p/19q codel of which 26 (33%) were still alive, in this subgroup median and 20-year survival after RT/PCV versus RT alone were 14 years and 37.1% versus 9.3 years and 13.6% (HR 0.60, 95% CI (0.35, 1.03), unadjusted p=0.06). Twenty year PFS in 1p/19q codel was 31.3% in RT/PCV treated patients and 10.8% in RT only treated patients (HR 0.49, 95% CI (0.29, 0.83), unadjusted p=0.007). In the 1p/19q codel subgroup age, WHO PS and necrosis at pathology were identified to be of independent prognostic value for OS.
 
 
 
 This long term analysis confirms the earlier conclusions and provides data on long term survival in this patient group. In 1p/19q codel patients treated with RT/PCV, the 20-year PFS and OS rates are 31% and 37% respectively.
