You R, et al. - In 148 patients with metastatic nasopharyngeal carcinoma (mNPC), the number of circulating tumor cells (CTCs) and Epstein-Barr virus DNA (EBV DNA) were analyzed for diagnosis, monitoring, and prognosis of mNPC. Researchers measured the levels of CTCs and EBV DNA at baseline and after first-line chemotherapy. Within the same time-frame, 122 non-metastatic NPC cases had their baseline CTCs and EBV DNA examined. For diagnosis of distant metastasis, CTCs showed improved specificity (86.0% vs 41.0%) and inferior sensitivity (42.3% vs 81.3%) vs EBV DNA. They observed significantly longer progression-free survival and overall survival for patients with conversion of baseline unfavorable CTCs and EBV DNA to favorable after first-line chemotherapy vs those with unfavorable CTCs and EBV DNA at both times. Findings thus suggest that additional prognostic information could be gained via measuring CTCs and EBV DNA in conjunction with imaging studies.