PC or PCV, That Is the Question: Primary Anaplastic Oligodendroglial Tumors Treated with Procarbazine and CCNU With and Without Vincristine.

While procarbazine with 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (PC) added to vincristine (PCV) was proven beneficial in the treatment of co-deleted anaplastic oligodendroglioma (AO), the question of whether PC alone is sufficient is important, as vincristine adds toxicity with uncertain benefit. This retrospective study provides a comparison of PC and PCV.Patients diagnosed with AO treated at the M.D. Anderson Cancer Center from June 1, 1993 to October 13, 2009 were selected from the database and were eligible if diagnosed with a primary AO and treated with either PC or PCV at some point. Ninety-seven patients were treated with such chemotherapy before first progression.Initial treatment included radiation and chemotherapy (81.4%) or chemotherapy alone (18.6%). Twenty-one patients (21.6%) received PC during primary treatment, while 76 patients (78.4%) received PCV. Eleven patients reported neurotoxicity in the PCV arm vs. none in the PC arm. Out of the 97 patients, 45 were alive at last contact, with a median follow-up of 9.9 years. The median overall survival was 6.5 years (95% confidence interval=4.8-16.7 years), while the median progression-free survival was 2.9 years (95% confidence interval=2.0-6.3 years); these differences were not significant (p=0.61 and p=0.28, respectively).Initial therapy with PC achieved comparable results to those of PCV with a median follow-up of 9.9 years. Neurotoxicity was more frequent with vincristine. Although selecting only for patients with AO, rather than those with mixed histology, increased the likelihood of selecting for patients with tumors with co-deletions, further studies with correlative co-deletion status are required.