KEY TAKEAWAYS
- AEWS1031 is a phase III trial that determined how different LC strategies, tumor size, and site affect treatment failure in patients with ES.
- The study compared two chemotherapy regimens in patients who completed treatment.
- Local and distant failures were evaluated, and significance was determined with a P-value ≤0.05.
- The study reported the lowest LF incidence to date in prospective ES trials. Larger tumor size was associated with higher LF.
The AEWS1031 phase III randomized trial evaluated how patients with localized Ewing sarcoma (ES) responded to different local control strategies.
Patients (pts) who had surgery alone, radiation therapy (RT), or both were followed for local failure (LF) (recurrence at the primary tumor site) and distant failure (DF) (recurrence at a distant site). The Fine and Gray method estimated the cumulative incidence of LF and DF. P-values were calculated using log-rank or Gray’s test, with significance at P ≤ 0.05.
A total of 588 pts completed local control (LC) treatment. The median age was 13 years, and tumor sites were categorized as extremity (39%), axial (24%), extraosseous (19%), and pelvis (18%). Tumor volume ≥200 mL was seen in 31% of patients, and maximum tumor dimension ≥8 cm in 52%. LC was achieved with surgery (54%), RT (27%), or surgery and RT (18%). R1 resection was seen in 13.1% of patients. LC with surgery was more common for extremity tumors, RT for pelvis tumors, and surgery and RT for axial and extraosseous tumors.
The 5-year cumulative incidences of LF and distant DF were 6% (95% CI, 4.3-8.3%) and 11% (95% CI, 8.6-13.9%), respectively. Eleven patients experienced simultaneous LF and DF. LF incidence was 5.0% for S, 8.4% for RT, and 5.6% for S+RT (P=0.47). DF incidence was 11.8% for S, 6.4% for RT, and 15.1% for S+RT (P=0.16). LF incidence based on tumor site was 3.6% for extremity, 8.7% for pelvis, 7.3% for axial, and 6.8% for extraosseous (P=0.08). LF incidence was higher for primary tumors ≥200 mL (11.3%) compared to tumors < 200 mL (3.9%; P<0.01) and for tumors ≥8 cm (7.8%) compared to tumors < 8 cm (4.4%; P=0.02). Tumor size was associated with a higher LF incidence for S and RT but not for S+RT. LF incidence was 4.0% for R0, 7.5% for R1 with RT, and 16.7% for R1 without RT (P=0.02). The study found the lowest LF incidence to date in prospective ES trials. Larger tumor size was associated with higher LF.
Source: https://meetings.asco.org/abstracts-presentations/220620
Clinical Trial: https://clinicaltrials.gov/study/NCT01231906
Safia K. Ahmed, Odion Binitie, Mark D. Krailo, Allen Buxton, Daniel J. Indelicato, Alexandra Callan, Alexander Christ, Paul J. Chuba, Helen Ruth Nadel, Bruce Pawel, Richard Greg Gorlick, Damon R. Reed, Steven G. DuBois, Katherine A. Janeway, Patrick Leavey, Leo Mascarenhas, and Nadia N. Laack | Journal of Clinical Oncology 2023 41:16_suppl, 11529-11529
