Capecitabine therapy in recurrent/metastatic nasopharyngeal cancers

e18515 Background: A wide range of chemotherapeutic agents have demonstrated antitumor activity in patients with recurrent or metastatic Nasopharyngeal Cancers (NPC). These therapeutic agents have different efficacy and toxicity profile. Capecitabine monotherapy had activity in recurrent/metastatic NPC based on small previous retrospective studies. The primary objective is to evaluate the overall response rate and tolerability of capecitabine in recurrent/metastatic NPC. Methods: A retrospective electronic chart review performed for 51 cases of recurrent/metastatic NPC patients who received capecitabine 1000-1,250 mg/m² twice daily two weeks on, one week off between 2011 to 2019 at King Faisal Specialist Hospital & Research Center (KFSH&RC). The Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 was used. Results: The median age at diagnosis was 42 years. 98% had a non-keratinized undifferentiated squamous cell carcinoma (Grade III). The most common sites for metastases were Bone (58.3%), Lung (50.0%), and liver (45.8%). 95% of patients received platinum-based chemotherapy and radiation therapy as the primary treatment. Capecitabine was used as the second or third line of treatment in the metastatic setting 45.1% and 43.1%, respectively. The patients tolerated the standard dose for a median of 6 cycles; only 20.0% of patients required a 25% dose reduction. The best response for capecitabine was complete response in 8 patients (15.7%), partial response in 14 patients (27.5%), stable disease in 10 patients, (19.6%), with a clinical benefit achieved in 32 patients (62.7%), and progressive disease in 16 patients (31.4%). The overall response rate to capecitabine was 43.2%, which was consistent regardless of the site of metastasis. The median progression-free survival was seven months (95%.CI: 5.3 -8.8). The one and three-year survival rates were 79% and 53%, respectively. Capecitabine was generally tolerated, the most common grade I & II adverse events were hand-foot syndrome (HFS) in 9 patients (20.5%), fatigue in 8 patients (15.7%), Diarrhea in 6 patients (11.7%), anemia in 5 patients (9.8 %), thrombocytopenia in 4 patients (7.8%) and neutropenia in 2 patients (4.0%). The most common grade III & IV was HFS in 3 patients (6%) and fatigue in one patient (2%) that led to treatment discontinuation after the first cycle. Conclusions: Capecitabine in Recurrent/Metastatic NPC is an effective and well-tolerated oral agent; however, a randomized prospective trial to evaluate capecitabine efficacy in this setting still recommended.