Dr Burtness on Subgroup Outcomes for Transoral Surgery and Risk-Based Radiation in HPV+ Oropharynx Cancer

Barbara Burtness, MD, professor of medicine, Medical Oncology, chief translational research officer, chief, Head and Neck Cancers/Sarcoma, co-leader, Developmental Therapeutics, associate cancer center director for translational research, Yale Cancer Center, discusses subgroup outcomes from the phase 2 E3311 trial (NCT01898494) evaluating primary transoral surgery and postoperative radiation deintensification strategies for patients with human papillomavirus (HPV)–associated oropharynx cancer.

The trial included patients with HPV-associated oropharynx cancer, who underwent transoral resection with neck dissection, and postoperative treatment was based on risk. Those with low-risk disease underwent observation (arm A), and patients with high-risk disease underwent intensity-modulated radiation therapy (IMRT) at 66 Gy in 33 fractions in combination with cisplatin (arm D). Patients with intermediate-risk disease were randomly assigned to receive IMRT at 50 Gy in 25 fractions (arm B) or 60 Gy in 30 fractions (arm C). Long-term data from the study presented at the 2024 ASCO Annual Meeting showed that at a median follow-up of 52.4 months, progression-free survival (PFS) and overall survival (OS) data remained favorable across all 4 treatment arms.

A subgroup analysis examined differences in outcomes based on tumor location (tonsil vs other oropharynx site), smoking history (≤10 pack years vs >10 pack years), and stage (pN2a vs pN2b-N3). Notably, previous reports have shown that having a smoking history of at least 10 pack years is associated with worse outcomes with chemoradiation for patients with HPV-associated head and neck cancer, Burtness notes. However, in this study, differences in outcomes were not observed based on pack years or current vs former smokers, she says. In patients who had a smoking history of no more than 10 pack years (n = 252) and those with a history of more than 10 pack years (n = 104), the 54-month PFS rates were 89.9% (95% CI, 85.9%-92.9%) and 91.7% (95% CI, 83.9%-95.9%), respectively (P = .91). The respective 54-month OS rates for this population were 95.5% (95% CI, 92.7%-97.2%) and 94.6% (95% CI, 89.1%-97.4%; P = .52).

Furthermore, in patients with a tonsil tumor (n = 231) and those with tumors at other oropharynx sites (n = 119), the respective 54-month PFS rates were 89.3% (95% CI, 84.9%-92.5%) and 92.9% (95% CI, 87.0%-96.2%; P = .28). The respective 54-month OS rates were 94.6% (95% CI, 91.5%-06.6%) and 96.6% (95% CI, 92.4%-98.5%; P = .35).

Regarding patients with pN2a disease (n = 87), the 54-month PFS and OS rates were 91.9% (95% CI, 84.3%-95.9%) and 96.4% (95% CI, 91.0%-98.6%), respectively. For patients with pN2B-N3 disease (n = 173), those respective rates were 89.4% (95% CI, 86.2%-93.1%; P = .76) and 95.2% (95% CI, 92.1%-96.7%; P = .8).