Treatment deintensification in human papillomavirus-positive oropharynx cancer: Outcomes from the National Cancer Data Base.

BACKGROUND: The growing epidemic of human papillomavirus-positive (HPV+) oropharyngeal cancer and the favorable prognosis of this disease etiology have led to a call for deintensified treatment for some patients with HPV+ cancers. One of the proposed methods of treatment deintensification is the avoidance of chemotherapy concurrent with definitive/adjuvant radiotherapy. To the authors' knowledge, the safety of this form of treatment de-escalation is unknown and the current literature in this area is sparse. The authors investigated outcomes after various treatment combinations stratified by American Joint Committee on Cancer (AJCC) eighth edition disease stage using patients from the National Cancer Data Base.

METHODS: A retrospective study of 4443 patients with HPV+ oropharyngeal cancer in the National Cancer Data Base was conducted. Patients were stratified into AJCC eighth edition disease stage groups. Multivariate Cox regressions as well as univariate Kaplan-Meier analyses were conducted.

RESULTS: For patients with stage I disease, treatment with definitive radiotherapy was associated with diminished survival compared with chemoradiotherapy (hazard ratio [HR], 1.798; P = .029), surgery with adjuvant radiotherapy (HR, 2.563; P = .002), or surgery with adjuvant chemoradiotherapy (HR, 2.427; P = .001). For patients with stage II disease, compared with treatment with chemoradiotherapy, patients treated with a single-modality (either surgery [HR, 2.539; P = .009] or radiotherapy [HR, 2.200; P = .030]) were found to have poorer survival. Among patients with stage III disease, triple-modality therapy was associated with improved survival (HR, 0.518; P = .024) compared with treatment with chemoradiotherapy.

CONCLUSIONS: Deintensification of treatment from chemoradiotherapy to radiotherapy or surgery alone in cases of HPV+ AJCC eighth edition stage I or stage II disease may compromise patient safety. Treatment intensification to triple-modality therapy for patients with stage III disease may improve survival in this group. Cancer 2018;124:717-26. © 2017 American Cancer Society.