Optimal timing of chemoradiotherapy after surgical resection of glioblastoma: Stratification by validated prognostic classification. Issue 14 (28th April 2020)

• Record Type: Journal Article
• Authors: Press, Robert H.; Shafer, Sarah L.; Jiang, Renjian; Buchwald, Zachary S.; Abugideiri, Mustafa; Tian, Sibo; Morgan, Tiffany M.; Behera, Madhusmita; Sengupta, Soma; Voloschin, Alfredo D.; Olson, Jeffrey J.; Hasan, Shaakir; Blumenthal, Deborah T.; Curran, Walter J.; Eaton, Bree R.; Shu, Hui‐Kuo G.; Zhong, Jim
• Is Part Of: Cancer. Volume 126:Issue 14(2020)
• Page Start: 3255
• Page End: 3264
• Publication Date: 2020-04-28
• Subjects: chemoradiotherapy -- adjuvant -- glioblastoma -- radiotherapy -- adjuvant -- timing of therapy; Cancer -- Periodicals; Cancer -- Cytopathology -- Periodicals; 616.99405
• DOI: 10.1002/cncr.32797
• Languages: English
• ISSNs: 0008-543X

Abstract

Abstract : Background: Previous studies examining the time to initiate chemoradiation (CRT) after surgical resection of glioblastoma have been conflicting. To better define the effect that the timing of adjuvant treatment may have on outcomes, the authors examined patients within the National Cancer Database (NCDB) stratified by a validated prognostic classification system. Methods: Patients with glioblastoma in the NCDB who underwent surgery and CRT from 2004 through 2013 were analyzed. Radiation Therapy Oncology Group recursive partitioning analysis (RPA) class (III, IV, V) was extrapolated for the cohort. Time intervals were grouped weekly, with weeks 4 to 5 serving as the reference category for analyses. Kaplan‐Meier analysis, log‐rank testing, and multivariate (MVA) Cox proportional hazards regression were performed. Results: In total, 30, 414 patients were included. RPA classes III, IV, and V contained 5250, 20, 855, and 4309 patients, respectively. On MVA, no time point after week 5 was associated with a change in overall survival for the entire cohort or for any RPA class subgroup. The periods of weeks 0 to 1 (hazard ratio [HR], 1.18; 95% CI, 1.02‐1.36), >1 to 2 (HR, 1.23; 95% CI, 1.16‐1.31), and >2 to 3 (HR, 1.11; 95% CI, 1.07‐1.15) demonstrated slightly worse overall survival (all P < .03). The detriment to early initiation was consistent across each RPA class subgroup. Conclusions: The current data provide insight into the optimal timing of CRT in patients with glioblastoma and describe RPA class‐specific outcomes. In general, short delays beyond 5 weeks did not negatively affect outcomes, whereas early initiation before 3 weeks may be detrimental. Abstract : The objective of this study is to better define the optimal time to initiate adjuvant therapy after surgical resection of glioblastoma while accounting for known prognostic factors by stratifying patients from a large cancer database using Radiation Therapy Oncology Group recursive partitioning analysis classification. The results demonstrate no clear overall survival detriment when adjuvant therapy is initiated beyond week 4 across each prognostic class, but survival is worse when it is initiated before week 3.