ASTRO 2019: Adding Cisplatin to Radiation Therapy in Advanced Oropharyngeal Cancer
Posted: Tuesday, October 8, 2019
Intensity-modulated radiation therapy (IMRT) plus cisplatin appears to be an effective treatment of oropharyngeal squamous cell carcinoma in terms of both 2-year progression-free survival and 1-year MD Anderson Dysphagia Inventory (MDADI); however, there are higher rates of grade 3 or higher acute toxicity with this combination compared with IMRT alone. Sue S. Yom, MD, PhD, of the University of California San Francisco, and colleagues presented an analysis of the phase II NRG-HN002 trial at the 2019 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract LBA10).
Researchers recruited 306 patients with histologically confirmed p16-positive oropharyngeal squamous cell carcinoma and a less than 10 pack/year smoking history. Patients were stratified by unilateral or bilateral radiation and were randomly assigned to receive either 60 Gy of IMRT plus 40 mg/m2 of cisplatin or 60 Gy of IMRT alone. Among the patients recruited, 84% were men, 52.6% had primary tonsil disease, and 80% had bilateral IMRT.
Of the 157 patients in the cisplatin cohort, 15.1% experienced grade 4 toxicities, and 64.5% had grade 3 acute toxicities. Patients not receiving cisplatin had grade 4 and grade 3 toxicity rates of 2.0% and 50.3%, respectively. No grade 5 toxicities were reported in either arm.
The MDADI completion rates were 77.1% in the IMRT-plus-cisplatin cohort and 71.1% in the IMRT cohort at 1 year, with both rates considered to pass the MDADI threshold. At the 2-year assessment, 292 patients remained for analysis of progression-free survival. The median follow-up was 2.6 years, and the 2-year progression-free survival estimate was 90.5% for the IMRT-plus-cisplatin cohort. In addition, the IMRT cohort had a progression-free survival of 87.5% at 2 years. Estimated 2-year overall survival rates were 96.7% in the cisplatin group and 97.3% in the IMRT-alone group.
Disclosure: The study authors’ disclosure information may be found at astro.org.