A large, randomized phase II/III trial, NRG Oncology HN005, evaluating de-intensified radiation treatments for early-stage, HPV-associated oropharyngeal cancer was halted after the control arm, receiving standard chemoradiation, achieved an unprecedented two-year progression-free survival rate of 98.1%. The study, presented at the American Society for Radiation Oncology (ASTRO) Annual Meeting, highlights the continued effectiveness of standard chemoradiation in this patient population.
Trial Details and Results
The trial randomized 382 patients with HPV-associated, locoregionally advanced oropharyngeal squamous cell carcinomas into three arms: standard radiation dosing (70 Gy) with cisplatin, reduced radiation (60 Gy) with cisplatin, and reduced radiation (60 Gy) with nivolumab. The primary endpoint was progression-free survival (PFS). After a median follow-up of 2.2 years, the two-year PFS estimates were 98.1% in the standard arm, 88.6% in the reduced radiation/chemotherapy arm, and 90.3% in the reduced radiation/immunotherapy arm. Two-year overall survival (OS) estimates were 99%, 98%, and 96.1%, respectively.
The de-intensified treatment arms failed to demonstrate non-inferiority compared to the standard treatment, leading to the early closure of the trial. This outcome underscores the importance of maintaining rigorous treatment standards for this cancer type.
Expert Commentary
Sue S. Yom, MD, PhD, FASTRO, principal investigator of the trial and the Irwin Mark Jacobs and Joan Klein Jacobs Distinguished Professor in Head and Neck Cancer Radiation Oncology at the University of California, San Francisco, emphasized the significance of the findings. "In cancer treatment, 98% progression-free survival at two years is a number you just don't see. It's the highest that has ever been published in the literature for head and neck cancer," she stated.
Dr. Yom also cautioned against premature adoption of de-intensified treatments. "Deintensification of chemoradiation treatments for HPV-associated oropharyngeal cancers is of very high interest to patients and researchers, but our study makes clear that these approaches should remain very experimental. Further work needs to be done to find ways that we can reduce side effects while maintaining these extremely high cure rates."
Context and Implications
Oropharyngeal cancer, affecting the middle part of the throat, is increasingly linked to HPV, with an estimated 70% or more of new cases in the U.S. being HPV-related. Patients with HPV-associated oropharyngeal cancers tend to be younger and have better outcomes compared to those with cancers caused by tobacco or alcohol use. While radiation therapy is effective, it can lead to severe and long-term side effects.
The trial's results suggest that current chemoradiation treatments have reached a point where long-term survival is increasingly common, shifting the focus to managing late toxicities. Future research should concentrate on identifying patients who may benefit from de-intensified approaches and developing personalized therapies to minimize unnecessary side effects.
The Path Forward
While de-intensification remains a goal, the current standard of care with chemoradiation continues to provide the best chance for a cure. As Dr. Yom noted, "At this point, neither of the deintensification options we tested would be appropriate for standard of care use, because you would actually be changing some patients' chance for a cure."
