A study published in The Lancet has shown a significant survival advantage for patients with oropharyngeal cancer treated with proton therapy compared to those receiving conventional radiation therapy. Led by researchers at The University of Texas MD Anderson Cancer Center, the trial is the first large randomized study to demonstrate a clear survival benefit with proton therapy in this patient population.
Earlier data on progression-free survival and treatment-related adverse effects were presented at the 2024 ASCO Annual Meeting, setting the stage for these definitive findings.
Experts Call for a Shift in Standard of Care
Commenting on the results, Steven Frank, MD, executive director of technology and innovation and deputy division head of strategic programs for Radiation Oncology at MD Anderson, said the findings provide level-one evidence that proton therapy improves both survival and quality of life. He added that the results strongly support proton therapy as the standard of care for advanced oropharyngeal cancer and could help expand patient access to this treatment.
Improved Survival and Reduced Toxicity
As reported by medicalxpress, the study evaluated 440 patients with stage III or IV oropharyngeal cancer treated across multiple U.S. centers. After five years, overall survival reached 90.9% in patients treated with intensity-modulated proton therapy (IMPT), compared with 81% in those who received intensity-modulated radiation therapy (IMRT), a statistically significant difference.
In addition, patients in the proton therapy group experienced fewer serious side effects. They were less likely to develop difficulty swallowing, feeding tube dependence, dry mouth, or severe lymphopenia, reflecting better preservation of normal tissues and immune function.
Why Proton Therapy Makes a Difference
Oropharyngeal cancers lie close to critical organs and sensitive tissues, making precise radiation delivery essential. Unlike traditional photon-based radiation, which passes through the body and exposes healthy tissue to entry and exit doses, proton therapy delivers radiation that stops at the tumor. As a result, IMPT reduces collateral damage while maintaining effective tumor control.
Robust Trial Design Supports Findings
This Phase III trial, the largest of its kind, randomized patients across 21 U.S. centers and stratified them by HPV status, smoking history, and prior induction chemotherapy. While three-year progression-free survival rates were similar between groups, five-year outcomes favored proton therapy.
Moving Toward More Personalised Care
Taken together, these findings reinforce the growing role of proton therapy in head and neck cancers. Researchers emphasize the need to further refine patient selection to ensure those most likely to benefit gain access to this advanced treatment.