Biopsy of distant metastasis is not a significant prognostic factor for synchronous metastatic nasopharyngeal carcinoma: a propensity score-matched analysis from the Surveillance Epidemiology and End-Results Registry

Introduction: Biopsy is essential for some patients with suspected distant metastasis, so we aim to figure out whether biopsy of distant metastasis is associated with impaired survival in NPC. Methods: A total of 743 synchronous metastatic NPC patients from 2004 to 2016 were analyzed from the population-based Surveillance, Epidemiology, and End Results program. Propensity score matching was used to control confounders and create a well-balanced cohort. Five-year survival rate estimates and Kaplan-Meier survival curves were calculated. Cox proportional hazard ratios (HRs) were used to identify independent prognostic factors for survival. Results: Of 743 eligible patients, 194 (26.11%) underwent biopsy of distant metastasis. After control for demographic and clinicopathologic characteristics, patients with biopsy of distant metastasis achieved comparable 5-year overall survival (OS) (20.3% vs 24.7%; P = 0.41) and 5-year cancer specific survival (CSS) (31.0% vs 33.6%; P = 0.35) with patients without biopsies. Multivariate analysis further confirmed that biopsy of distant metastasis was not associated with impaired OS (HR = 1.03, 95% CI = 0.84-1.25; P = 0.80) or CSS (HR = 1.07, 95% CI = 0.86-1.34; P = 0.54). Conclusions: Biopsy of distant metastasis was not associated with impaired survival outcomes for synchronous metastatic NPC patients. Biopsy of distant metastasis could be another diagnosed choice for patients with suspected distant metastasis.