Pathologic responses and clinical outcomes with neoadjuvant doublet chemotherapy for newly diagnosed, surgically-resectable p16-positive oropharyngeal cancer.

BACKGROUND: The feasibility and outcomes of neoadjuvant doublet chemotherapy with cisplatin and docetaxel followed by surgical resection of residual disease (NAC + S) for patients with newly diagnosed, resectable p16 positive (+) oropharyngeal squamous cell carcinoma (OPSCC) has been reported from a single institution. Here, we report pathologic responses, need for adjuvant treatment and recurrence-free survival (RFS) following this treatment from a second large academic institution. METHODS: A retrospective cohort study of patients with p16 + OPSCC receiving NAC + S and risk-adjusted adjuvant treatment between January 2017 and March 2024 was performed. RESULTS: Of the 76 patients who met the inclusion criteria, 43 (57%) patients developed clinical-to-pathologic downstaging; all remaining patients had clinical and pathologic stage I disease (AJCC 8th). Thirty-seven (49%) patients experienced complete pathologic response (pCR). Sixty-four (89%) patients avoided adjuvant treatment. Two-year overall survival (OS) and RFS were 93.7% and 75.4%, respectively. Development of a pCR did not statistically associate with improved RFS, but only 8 patients developed disease relapse. Of the 8 (11%) patients that recurred, 3 had developed a pCR and 5 had not. CONCLUSIONS: Using risk-adjusted criteria from pathologic analysis, a high proportion of patients with newly diagnosed, resectable p16 + OPSCC appear to be able to avoid adjuvant treatment following the NAC + S treatment regimen without sacrificing disease control. Prospective clinical study of the NAC + S treatment strategy with clearly defined inclusion and adjuvant treatment criteria is warranted to determine whether this approach strategy can be safely offered to patients that wish to minimize the need for adjuvant radiation.