Forster, Kenneth

7501 Background: The first objective of RTOG 0617 was to compare the overall survival(OS) of patients(pts) treated with standard-dose(SD)(60Gy) versus high-dose(HD)(74Gy) radiotherapy with concurrent chemotherapy(CT). Methods: This Phase III Intergroup trial randomized 464 pts with Stage III NSCLC to the SD(60Gy) vs. HD(74Gy) arms prior to closure of the HD arm. Concurrent CT included weekly paclitaxel(45 mg/m2) and carboplatin(AUC=2). Pts randomized to cetuximab received a 400 mg/m2 loading dose on Day 1 followed by weekly doses of 250 mg/m2. All pts were to receive consolidation CT. We are reporting the final results on radiation dose. Results: 464 pts were accrued prior to closure of the HD arm in 6/11, of which 419 were eligible for analysis. Median follow up was 17.2 months. There were 2 and 10 grade 5 treatment-related adverse events(AEs) on the SD and HD arms, respectively. Grade 3+AEs were 74.2% and 78.2% on SD and HD arms, respectively (p=0.34). The median survival times and 18-month OS rates for the SD and HD arms were 28.7 vs 19.5 months, and 66.9% vs 53.9% respectively (p=0.0007). The primary cause of death was lung cancer (72.2% vs 73.5%)(p=0.84). Local failure rates at 18 months were 25.1% vs 34.3% for SD and HD patients, respectively(p=0.03). Local-regional and distant failures at 18 months were 35.3% vs 44%(p=0.04) and 42.4% vs 47.8%(p=0.16) for SD and HD arms, respectively. Factors predictive of less favorable OS on multivariate analysis were higher radiation dose, higher esophagitis/dysphagia grade, greater gross tumor volume, and heart volume >5 Gy. Conclusions: In this setting of chemoradiation for locally-advanced Stage III NSCLC, 60 Gy is superior to 74 Gy in terms of OS and local-regional control. The effect of the anti-EGFR antibody (cetuximab) awaits further follow up. This project was supported by RTOG grant U10 CA21661, CCOP grant U10 CA37422, and ATC U24 CA 81647 from the National Cancer Institute (NCI) and Eli Lilly and Company. Clinical trial information: NCT00533949.

PURPOSE RTOG 0617 compared standard-dose (SD; 60 Gy) versus high-dose (HD; 74 Gy) radiation with concurrent chemotherapy and determined the efficacy of cetuximab for stage III non–small-cell lung cancer (NSCLC). METHODS The study used a 2 × 2 factorial design with radiation dose as 1 factor and cetuximab as the other, with a primary end point of overall survival (OS). RESULTS Median follow-up was 5.1 years. There were 3 grade 5 adverse events (AEs) in the SD arm and 9 in the HD arm. Treatment-related grade ≥3 dysphagia and esophagitis occurred in 3.2% and 5.0% of patients in the SD arm v 12.1% and 17.4% in the HD arm, respectively ( P = .0005 and < .0001). There was no difference in pulmonary toxicity, with grade ≥3 AEs in 20.6% and 19.3%. Median OS was 28.7 v 20.3 months ( P = .0072) in the SD and HD arms, respectively, 5-year OS and progression-free survival (PFS) rates were 32.1% and 23% and 18.3% and 13% ( P = .055), respectively. Factors associated with improved OS on multivariable analysis were standard radiation dose, tumor location, institution accrual volume, esophagitis/dysphagia, planning target volume and heart V5. The use of cetuximab conferred no survival benefit at the expense of increased toxicity. The prior signal of benefit in patients with higher H scores was no longer apparent. The progression rate within 1 month of treatment completion in the SD arm was 4.6%. For comparison purposes, the resultant 2-year OS and PFS rates allowing for that dropout rate were 59.6% and 30.7%, respectively, in the SD arms. CONCLUSION A 60-Gy radiation dose with concurrent chemotherapy should remain the standard of care, with the OS rate being among the highest reported in the literature for stage III NSCLC. Cetuximab had no effect on OS. The 2-year OS rates in the control arm are similar to the PACIFIC trial.