TUESDAY, Dec. 30, 2025 (HealthDay News) -- For patients with stage III or IV oropharyngeal cancer, intensity-modulated proton therapy (IMPT) is noninferior to intensity-modulated radiation therapy (IMRT) for progression-free survival, according to a study published online Dec. 11 in The Lancet.
Steven J. Frank, M.D., from The University of Texas MD Anderson Cancer Center in Houston, and colleagues conducted a noninferiority, phase 3 trial at 21 sites to compare IMRT to IMPT for patients with stage III or IV oropharyngeal cancer. A total of 160 and 136 patients, respectively, received IMPT and IMRT.
The researchers found that progression-free survival rates were 82.5 and 81.3 percent at three and five years, respectively, for the IMPT group, compared with 83.0 and 76.2 percent, respectively, for the IMRT group (hazard ratio, 0.88; 95 percent confidence interval, 0.57 to 1.35; P = 0.005 for noninferiority of IMPT). At five years, overall survival rates were 90.9 and 81.0 percent after IMPT and IMRT, respectively (hazard ratio, 0.58; 95 percent confidence interval, 0.34 to 0.99; P = 0.045). Treatment-related deaths occurred in six and three patients in the IMRT and IMPT groups, respectively, and deaths from disease progression occurred in 18 and nine patients, respectively. The five-year disease control rates were similar between treatment groups (local recurrences, 2.9 versus 5.6 percent [P = 0.474]; regional recurrences, 3.4 versus 3.2 percent [P = 0.860]; distant metastases, 9.1 versus 8.9 percent [P = 0.897] for IMPT versus IMRT).
"These results indicate a survival benefit for proton therapy in oropharyngeal cancer patients as well as reduced high-grade toxicities during treatment and less feeding tube dependence," Frank said in a statement.
Several authors disclosed ties to the biopharmaceutical industry.