Capecitabine for Salvage Treatment of Patients With Heavily Pretreated Human Papillomavirus-Associated Oropharynx Cancer With Distant Metastases

Background: Patients with metastatic human papillomavirus-associated oropharyngeal cancer (HPV-OPC) have a median overall survival exceeding 2 years and are often candidates for multiple lines of palliative therapy. With the approval of immunotherapy as first-line treatment, salvage therapeutic options are limited. We describe our experience using capecitabine as salvage therapy for patients with recurrent or metastatic (R/M) HPV-OPC.

Methods: We performed a retrospective study of patients with R/M HPV-OPC with distant metastatic disease. Eligible patients were identified from a medical oncology clinical database. Demographic and clinical data were abstracted from the medical record. Survival probabilities were estimated with the Kaplan-Meier method.

Results: 10 patients were identified. Sites of metastatic disease included lung, liver, mediastinal lymph nodes, bone, abdominal lymph nodes, and soft tissue. Most patients received capecitabine as fourth-line treatment. The median duration from start of capecitabine therapy until death was 10.5 months. Best treatment response was as follows: partial responses (PR) were seen in 4 of 10 (40%), stable disease (SD) in 3 of 10 (30%), and progressive disease (PD) in 2 of 10 (20%). The clinical benefit rate (CR + PR + SD) was 70%. Reasons for discontinuation included disease progression ( = 8) and side effects ( = 2). One patient notably had prolonged benefit from capecitabine and continued to be on treatment for 34 months total.

Conclusions: Capecitabine is a potential salvage treatment for heavily pretreated patients with R/M HPV-OPC, with some patients experiencing prolonged response. Clinical or molecular predictors of response would be helpful to identify patients likely to benefit; a larger prospective study would be useful to confirm efficacy in this patient population.