Long-term recurrence-free survival after an unplanned reduction in radiotherapy for HPV-positive oropharyngeal SCC: Two cases and a review of the literature.

There is currently no clear distinction between the treatment of HPV-positive and HPV-negative oropharyngeal squamous cell carcinoma (OPSCC). HPV-positive OPSCC has been demonstrated to be more radiosensitive than its HPV-negative counterpart. Despite this, patients with HPV-positive OPSCC continue to receive a full dose of radiation (70 Gy) outside clinical trials. However, this high dose comes with considerable morbidities, including severe mucositis, dysphagia, and xerostomia. We describe the cases of 2 patients with HPV-positive OPSCC who received two cycles of high-dose cisplatin at 100 mg/m2 on 3 separate days, along with concurrent radiotherapy at 50 Gy in 25 fractions for one and 46 Gy in 23 fractions for the other. During treatment, both patients experienced significant acute-phase toxicities-including grade 3 mucositis, grade 3 nausea, and grade 2 dermatitis-and their treatment regimen was stopped before its planned completion. Nevertheless, after a follow-up of 75 and 78 months, respectively, neither patient exhibited any evidence of disease. Late toxicities included grade 1 xerostomia, grade 1 pharyngeal-phase dysphagia, and grade 1 dysgeusia with some foods. We conclude that de-escalating the dose of radiation for HPV-positive patients by 30% and identifying which patients can safely be treated with this level of dose reduction warrants further study.