Short-term versus long-term metronomic adjuvant chemotherapy in locally advanced nasopharyngeal carcinoma: A propensity score-matched real-world study

•The optimal duration of metronomic chemotherapy (MTCD) as adjuvant chemotherapy in patients with locally advanced NPC could be recommended for > 3 months.•MTCD as adjuvant chemotherapy was an independent factor affecting OS, PFS, and DMFS prognosis.•Metronomic adjuvant chemotherapy was mildly toxic and tolerable. This retrospective study aimed to determine the optimal metronomic chemotherapy duration (MTCD) as adjuvant therapy for patients with locally advanced nasopharyngeal carcinoma (LANPC). This study involved LANPC patients treated with metronomic chemotherapy (MTC) using a 5-FU prodrug (S1, capecitabine, or tegafur) from May 2013 to September 2020. The optimal MTCD threshold was established using X-tile Bioinformatics software. The overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) were compared between short-term and long-term groups using propensity score matching (PSM). A total of 546 patients were analyzed. MTCD was an independent prognostic factor for OS, PFS, and DMFS (all P 3 months) and short-term (≤3 months) MTCD groups. After a median follow-up of 48 months, significant differences were observed in 4-year OS (97.0 % vs. 87.1 %; P