Abstract
BACKGROUND: For many years, patients with anaplastic oligodendrogliomas (AO) have been treated with radiation and temozolomide followed by adjuvant temozolomide (RT/TMZ). Two randomized studies, RTOG 9402 and EORTC 26951 recently showed significantly improved survival in patients with 1p/19q co-deleted AO treated with radiation plus PCV (RT/PCV) versus radiation alone. A randomized controlled study comparing RT/PCV with RT/TMZ is underway, but obtaining definitive answers takes long as AO are rare and survival is long. Our goal was to assess the feasibility of a retrospective analysis to compare RT/TMZ and RT/PCV. METHODS: This was a retrospective, single institution analysis of co-deleted AO treated with RT/TMZ at Johns Hopkins between 2004 and 2012, meeting selection criteria for the subgroup analysis of RTOG 9402 and EORTC 26951: AO or AOA, co-deletion of 1p/19q, age ≥ 18, no prior therapy except surgery. An initial screen of the cancer center database used broad search terms to assure capture of all cases. RESULTS: Of 544 potential patients filtered with the initial screen, only 12 conformed to all eligibility criteria of the subgroup analysis of RTOG 9402 and EORTC 26951. The reasons for exclusion included: Not AO, not co-deleted, 1p/19q co-deletion testing not performed, patients received prior or other therapies or treatment elsewhere. Median age of the 12 patients: 37 (range: 34-73), 50% female. Median follow-up time: 6.2 years for OS (range: 1.5-8.3), 5.3 years for PFS (range: 1.0-7.0). 2 patients progressed, 1 died of disease. Median OS and PFS: Not yet reached. CONCLUSIONS: This exploratory analysis from an active tertiary referral center highlights limitations of a retrospective analysis of patients with co-deleted AO treated with RT/TMZ in an effort to determine how RT/TMZ compares with RT/PCV. Only a prospective randomized controlled trial, such as the CODEL study, will define optimal treatment for these patients.