Anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA) are uncommon malignant tumors occurring in adults, but have garnered attention because of a high rate of response to chemotherapy in early studies. However, no clinical trial had demonstrated benefit with the addition of chemotherapy to radiotherapy alone until the long-term results of RTOG 9402 and EORTC 26951. These studies revealed prolonged survival in patients with anaplastic gliomas harboring the 1p/19q codeletion when treated with PCV (procarbazine, lomustine, and vincristine) and radiation therapy compared with radiation alone. These studies validated the use of 1p/19q codeletion status as a predictive biomarker in these tumors. Additional molecular characterization of these tumors may provide additional insight into treatment decisions, although these characterizations have yet to be fully elucidated. Even with the strength of the data advocating the use of combination therapy (PCV and radiotherapy), the incorporation of newer, less-toxic drugs such as temozolomide into many practices in the past decade raises important questions regarding the optimal chemotherapy regimen. Unfortunately, additional definitive phase III trials will take several years to answer remaining questions. Regardless, it is clear that patients with 1p/19q codeleted AO or AOA who can tolerate chemotherapy should not receive radiotherapy alone.
Mark D. Anderson and Mark R. Gilbert
Michael R. Abern, Richmond A. Owusu, Mark R. Anderson, Edward N. Rampersaud and Brant A. Inman
The role for a single dose of intravesical chemotherapy (IVC) after transurethral resection (TUR) remains unclear in patients with non–muscle-invasive bladder cancer (NMIBC). Several recent randomized clinical trials (RCTs) have evaluated its effect on recurrence, prompting this systematic review of RCTs comparing a single immediate postoperative dose of IVC versus placebo within 24 hours of TUR of NMIBC, and this meta-analysis using a random-effects model to predict the pooled relative risk (RR) of tumor recurrence. Subanalyses pooled studies by drug type and a meta-regression was performed to determine the effect of underlying patient risk factors on the efficacy of a single dose of IVC. A total of 3103 patients were randomized in the 18 RCTs that met inclusion criteria. The recurrence rate in patients receiving perioperative IVC and TUR was 37% versus 50% in the TUR-alone group. The pooled RR of recurrence for IVC and TUR was 0.67 (95% CI, 0.56–0.79), corresponding to a 13% absolute reduction and a number needed to treat of 7.2 patients to avoid 1 recurrence. The proportions of patients with tumor risk factors (T1, high-grade, multifocal, or recurrent) were not associated with IVC efficacy. A single dose of IVC administered within 24 hours of TUR of NMIBC was found to result in a reduction in tumor recurrence (RR, 0.67; 95% CI, 0.56–0.79). Patients with higher-risk tumor features seem to benefit at a similar rate.