Phase III study of radiation therapy (RT) with or without procarbazine, CCNU, and vincristine (PCV) in low-grade glioma: RTOG 9802 with Alliance, ECOG, and SWOG.

Central Nervous System Tumors
Session Type and Session Title: 
Oral Abstract Session, Central Nervous System Tumors
Abstract Number: 
J Clin Oncol 32:5s, 2014 (suppl; abstr 2000)
Jan C. Buckner, Stephanie L. Pugh, Edward G. Shaw, Mark R. Gilbert, Geoffrey Barger, Stephen Coons, Peter Ricci, Dennis Bullard, Paul D. Brown, Keith Stelzer, David Brachman, John H. Suh, Christopher J. Schultz, Jean-Paul Bahary, Barbara Jean Fisher, Harold Kim, Albert D Murtha, Walter J. Curran, Minesh P. Mehta; Mayo Clinic, Rochester, MN; Statistical Center, Radiation Therapy Oncology Group, Philadelphia, PA; Wake Forest University, School of Medicine, Winston-Salem, NC; The University of Texas MD Anderson Cancer Center, Houston, TX; Wayne State University, School of Medicine, Detroit, MI; Barrow Neurological Institute, Phoenix, AZ; Radiology Imaging Associates, Englewood, CO; Triangle Neurosurgery, Raleigh, NC; Mid-Columbia Medical Center, The Dalles, OR; Arizona Oncology Services Foundation, Phoenix, AZ; Cleveland Clinic, Cleveland, OH; Medical College of Wisconsin, Milwaukee, WI; Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal, Montreal University, Montreal, QC, Canada; London Regional Cancer Program, London, ON, Canada; Karmanos Cancer Institute, Wayne State University, Detroit, MI; Cross Cancer Institute, Edmonton, AB, Canada; Radiation Therapy Oncology Group; Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA; University of Maryland, Baltimore, MD

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Abstract Disclosures


Background: Early results of R9802 (Shaw et al: J Clin Oncol. 2012; 30(25):3065-70) demonstrated that PCV given with RT at the time of initial diagnosis prolongs progression-free survival (PFS), but not overall survival (OS), compared with RT alone. Herein, we report long term follow up results. Methods: Eligibility criteria included age <40 years with subtotal resection or biopsy, age >40 with any extent of resection, and supratentorial grade II astrocytoma (A), oligo-astrocytoma (OA), or oligodendroglioma (O). Patients were stratified by age, histology, Karnofsky Performance Status, and presence versus absence of contrast enhancement on the preoperative imaging study and randomized to RT alone (54 Gy in 30 fractions) or RT followed by 6 cycles of PCV chemotherapy. Wilcoxon test was used to compare survival distributions. Cox proportional hazard models were used to identify prognostic variables. Results: 251 eligible patients were accrued from 1998 to 2002. Median follow up is 11.9 years; 55% of patients have died. Patients in the RT + PCV arm have significantly longer median survival time (MST) compared to the RT alone arm (13.3 vs. 7.8 years, p=0.03; HR=0.59) and longer median PFS (10.4 vs. 4.0 years, p=0.002; HR=0.50). 5 and 10 year OS for RT + PCV vs RT alone are 73% vs 64%, and 62% vs 41%, respectively. Cox model identified RT + PCV treatment arm as a favorable prognostic variable for OS (p=0.003; HR 0.60) and PFS (p<0.001; HR=0.49). A or A-dominant OA histology (vs O or O-dominant OA) was prognostic for worse OS (p<0.001; HR=2.16) and PFS (p<0.001; HR 1.85). Male OS but not PFS was worse than females (p=0.02; HR 1.51). Analyses of 1p/19q co-deletions and IDH mutations have not yet been completed. Conclusions: For grade 2 glioma patients with less than gross total tumor resection or >40 years of age, PCV + RT prolongs both OS and PFS compared with RT alone. Patients with A or A-dominant OA have worse outcomes, as do males. Multivariable models that incorporate 1p/19q co-deletion and IDH mutational analyses may more fully elucidate the magnitude of treatment benefit for patients with tumors identified by specific histologic type and molecular markers. Clinical trial information: NCT00003375.