For patients with glioblastoma, short delays in the initiation of chemoradiotherapy after surgery did not appear to be linked to worse overall survival (OS) — yet initiation too soon after surgery was, found a study reported in Cancer.

The study included 30,414 patients from the National Cancer
Database (NCDB) who had glioblastoma and underwent surgery followed by
chemoradiotherapy between 2004 and 2013.

Receipt of chemoradiotherapy was categorized by week after
surgery: 0 to 1 weeks, more than 1 to 2 weeks, more than 2 to 3 weeks, more
than 3 to 4 weeks, more than 4 to 5 weeks, more than 5 to 6 weeks, more than 6
to 7 weeks, more than 7 to 8 weeks, and more than 8 weeks. Patients received
chemoradiotherapy a median of 28 days (± 15.8 days) after surgery.

Patients were grouped according to the recursive partitioning
analysis (RPA) classification system, derived from a pooled analysis of 4
Radiation Therapy Oncology Group (RTOG) clinical trials. Most patients were
grouped as RPA class IV (68.6%) and the remaining as class III (17.3%) or class
V (14.2%).

A multivariate analysis showed that receipt of
chemoradiotherapy at any time interval beyond 5 weeks was not linked to worse
OS, yet initiation of chemoradiotherapy within 1 week (hazard ratio [HR], 1.18;
95% CI, 1.02-1.35), more than 1 to 2 weeks (HR, 1.23; 95% CI, 1.16-1.31), and
more than 2 to 3 weeks after surgery (HR, 1.11; 95% CI, 1.06-1.15) were linked to
worse OS.

An additional multivariate analysis indicated that receipt of
chemoradiotherapy within 3 weeks after surgery was consistently associated with
worse OS across RPA classes III, IV, and V, “suggesting that it cannot be
attributed entirely to patients with a poor prognosis,” the study authors

“This study is not advocating for delaying treatment as a new
standard of care,” the study authors cautioned. These data, they explained,
“favor avoiding the initiation of adjuvant therapy within the first 3 weeks
after surgery if possible and could be used to reassure patients and providers
in the scenario of unexpected delays.”


Press RH, Shafer SL, Jiang R, et al. Optimal timing of chemoradiotherapy after surgical resection of glioblastoma: Stratification by validated prognostic classification [published online April 28, 2020]. Cancer. doi: 10.1002/cncr.32797

This article originally appeared on Cancer Therapy Advisor

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