Excellent response of cetuximab plus chemotherapy after pembrolizumab monotherapy in metastatic hypopharyngeal cancer: A case report

Patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) typically have an unfavorable prognosis, with a median survival of only 6 to 15 months in most studies. In cases other than local relapse or oligometastases, systemic therapy plays the dominant role. The choice of regimen is influenced by multiple clinical factors, including patient comorbidities, performance status, previous therapy, and pathologic features. We present a case of PD-L1 (programmed death-ligand 1)-negative metastatic hypopharyngeal cancer successfully treated with pembrolizumab monotherapy, followed by cetuximab combined with chemotherapy. Remarkably, the patient currently remains in good health, with no signs of disease on imaging at 35 months after diagnosis. We emphasized the importance of a well-devised treatment strategy, as well as the significant synergistic effects of the sequence in which the cetuximab-based regimen follows immune checkpoint inhibitors.