NT-22 * PAV TREATMENT WITHOUT IMMEDIATE RADIOTHERAPY FOR ANAPLASTIC OLIGODENDROGLIAL TUMOR WITH 1p/19q CO-DELETION

Abstract

OBJECTIVE: Recently, two randomized control trial, EORTC 26951 and RTOG 9402, has clarified that PCV + Radiation Therapy (RT) has survival benefit compared to in anaplastic oligodendroglial tumor and 1p/19q co-deleted tumor is a good prognosis factor. However, it is still unclear that RT is always necessary in both 1p/19q status tumor. MATERIAL AND METHODS: We retrospectively analyzed PFS and OS in thirty-three consecutive patients with anaplastic oligodendroglial tumor, who had been treated according to our treatment strategy. Briefly, in 1p/19q co-deleted case, only PAV chemotherapy is administrated after initial surgery without immediate RT. For recurrence, PAV or TMZ chemotherapy is considered after re-evacuation of local recurrence and definition of LOH status. In non-co-deleted case, immediate RT with TMZ or PAV is considered as a first-line therapy. RESULTS: With a median follow-up of 35.1 months, PFS and OS were 32.4 and 52.9 months, respectively, in all of our patients. In 1p/19q co-deleted tumor, PFS and OS were 58.8 months and N.R., which were significantly longer than those in non-co-deleted tumor, 10.2 and 27.3 months, respectively. CONCLUSION: In co-deleted cases, our data showed shorter PFS than two of Phase III trials (58.8 vs. 157 or 100.8 months). However OS was N.R. and no remarkable differences were found in PFS and OS of all of our cases compared to RT/PCV arms. It may suggest that tumors without RT are still sensitive to adjuvant chemotherapy after recurrence and such shorter-time recurrence would not influence on survival time in co-deleted cases.