Aggressive de-escalation of chemoradiation after surgery in patients with HPV-associated oropharynx squamous cell carcinoma (OPSCC) led to similar disease control and improved quality of life and safety profile compared with historical controls, according to data presented at the 59th Annual Meeting of the American Society for Radiation Oncology (ASTRO).
For the single-arm phase 2 MC1273 study, 80 patients with OPSCC after surgery received 12 days of radiation twice daily for a total dose 30 Gy and 2 courses of docetaxel 15 mg/m2. Patients with extracapsular extension (ECE), an indicator of aggressive disease, received additional doses of radiation for a total dose of 36 Gy. The standard radiation dose is 60 to 66 Gy.
Patients eligible for the study had a 10 pack-years or less smoking history, and negative margins postresection surgery.
At the median follow-up of 2 years after treatment, patients achieved a locoregional control rate of 95%, distant control rate of 94%, and a disease-free survival rate of 89%.
Patients also experienced an improvement in swallowing function, as determined by the Modified Barium Swallow Impairment Profile (MBSImP) from baseline to 1-year follow-up (P =.03), and none of the study patients required placement of a feeding tube.
The rates of grade 2 to grade 3 or greater adverse events were 12% and 3%, 1% and 0%, and 10% and 0% prior to therapy, at year 1, and at year 2, respectively. All instances of grade 3 or greater adverse effects occurred by 3 months and resolved by 6 months.
Patients experienced a decrease in quality of life as it pertained to xerostomia (P <.0001), but all other aspects of quality of life remained the same or improved compared with the control.
The authors added that a follow-up phase 3 trial is currently underway.
1. Ma DJ, Price K, Moore EJ, et al. Two-year results for MC1273, a phase II evaluation of aggressive dose de-escalation for adjuvant chemoradiation in HPV+ oropharynx squamous cell carcinoma (OPSCC). Oral presentation at: 59th Annual Meeting of the American Society for Radiation Oncology; September 24-27, 2017; San Diego, CA. Abstract LBA-14.