More is not better when it comes to radiation therapy administered with concurrent chemotherapy for unresectable stage III non–small cell lung cancer (NSCLC), suggests a long-term update of the RTOG 0617 trial.
Initial results of the phase 3 randomized controlled trial, at a median follow-up of 1.9 years, showed that median overall survival was about 8 months longer with the 60-Gy standard dose of radiation compared with a 74-Gy high dose, each given along with paclitaxel and carboplatin (Lancet Oncol. 2015;16:187-99).
The update, now at a median follow-up of 5.1 years and reported in the Journal of Clinical Oncology, recapitulates that finding, again showing a roughly 8-month longer overall survival with the standard dose of radiation. Results continue to show no benefit of adding the anti-EGFR antibody cetuximab (Erbitux) to treatment.
“The 5-year overall survival estimate for the standard-dose radiation arm of RTOG 0617, regardless of cetuximab delivery, was 32.1%. This is among the highest overall survival results of any phase III trial for patients with stage III NSCLC,” noted the investigators, led by Jeffrey D. Bradley, MD, department of radiation oncology, Emory University, Atlanta.
“These results argue strongly that the current standard-of-care radiation dose should be 60 Gy given in 2-Gy daily fractions to a target volume directed at tumor plus margin on the basis of CT and PET/CT, excluding elective nodal irradiation.”
The RTOG 0617 trial was conducted among 496 patients with unresectable stage III NSCLC in the United States and Canada. They were randomized to receive standard-dose or high-dose radiation in addition to concurrent chemotherapy, and randomized again to receive cetuximab or not.