Introduction
Nasopharyngeal carcinoma (NPC) has distinct geographical distribution and Chinese contribute to 47.7% of newly diagnosed cases each year(1). Distant metastasis is the main treatment failure modality as well as the most common factor for cancer-related death for NPC patients. Metastatic NPC patients have poor prognosis with mere 20 months of overall survival(2). Up to 10% of new NPC cases were de novo metastatic nasopharyngeal carcinoma, and 6%-15% non-metastatic NPC patients experienced distant metastasis.(3, 4). Given its high incidence and fatality, treatment for advanced NPC is the most challenging task for NPC management.
When mNPC patients have objective response to more than 4 cycle of chemotherapy, applying maintenance therapy represents promising prognosis. The most common regimens are orally administrated fluoropyrimidine such as Capecitabine and anti-PD-1 monoclonal antibody immunotherapy for the low toxicity and good appliance. It is reported in a phase 3 randomized clinical trail that Capecitabine maintenance therapy can significantly increase the median PFS of de novo mNPC patients from 8.2 months to 35.9 months(5). For recurrent or metastatic NPC patients undergoing first line treatment, adding immunotherapy to chemotherapy and following by anti-PD-1 monoclonal antibody maintenance reduced their tumor progression risk by half, and extended their median progression free survival (PFS) from 8.2 months to 21.4 months(6).
Diverse tolerance for the two regimens and the financial status of patients are always primary considerations in treatment decision-making. However, it still lacks evidence to conclude which better extends patients’ progression free survival and overall survival. This study aims to investigate the survival impact of orally administrated fluoropyrimidine, anti-PD-1 immunotherapy and their combined effect as maintenance therapy for metastatic NPC patients following first line intravenous chemotherapy.