Oral Maintenance Chemotherapy Using S-1/Capecitabine In Metastatic Nasopharyngeal Carcinoma Patients After Systemic Chemotherapy:A Single Institution Experience

ObjectiveIn this study,we retrospectively evaluated a series of metastatic nasopharyngeal carcinoma(mNPC)patients who received oral maintenance chemotherapy using S-1/capecitabine after systemic chemotherapy,aimed to explore potential efficient treatment strategy for this subset of patients.Materials and MethodThirty-seven patients with mNPC(19 newly diagnosed metastatic patients and 18 metastatic cases after definitive chemoradiotherapy)at Fujian Medical University Cancer Hospital were analyzed from June 2013 to December 2017.Of whom 24 were diagnosed with oligometastasis NPC,while 13 were considered as multiple metastases cases.Except for bone-only metastatic disease,others should be at least one measurable disease.All patients achieved a response of at least stable disease(SD)before maintenance chemotherapy.The dose of S-1/ capecitabine was determined according to the body surface area(BSA).S-1 was given on days 1–14,4 weeks is 1 cycle for 24 cycles.We analyzed the efficacy and toxicity of S-1 maintenance therapy.ResultAfter a median follow-up time of 37 months,a total of 18 patients were classified as progressive disease and 5 patients had died.The 3-year progression-free survival(PFS)and overall survival(OS)rate were 47.6% and 87.7%,respectively.The median time-to-progression was 27.6 months,while the median OS was not reached.No statistical difference was observed in OS and PFS between smNPC and mmNPC.At the time of censoring,10 patients had completed 2 years of maintenance chemotherapy(24cycles)and five were still in the maintenance phase,while 22 had discontinued(fourteen owing to disease progression and 8 for other reasons).Generally,the treatment was generally well tolerated.The most common acute adverse events were grade 1–2gastrointestinal side effects,hematological toxicity and liver dysfunction during systemic chemotherapy.During the maintenance setting,the most common toxicities were hematological-related events of grade 1–2,with only seven patients developing grade 3 toxicities.No grade 4-5 adverse effects were recorded.ConclusionOral maintenance chemotherapy using S-1/capecitabine in mNPC patients after systemic chemotherapy is safe and effective,with good tolerance and mild side effects.It is expected to become a treatment mode for mNPC.Further multicenter prospective clinical trials are warranted.