Prognostic signifi cance of pre-treatment latent membrane protein 1 from nasopharyngeal swabs for stage III-IVA nasopharyngeal carcinoma

Abstract

Background Previous studies have proposed that the latent membrane protein 1 (LMP1) gene is related to the pathogenesis and progression of nasopharyngeal carcinoma. However, the role of pretreatment LMP1 as a prognostic factor has not been fully addressed, and most previous studies did not utilize polymerase chain reaction detection techniques. We aimed to investigate whether the presence of pre-treatment LMP1 from nasopharyngeal swabs detected by polymerase chain reaction would allow prognostication and potentially treatment stratification prior to any intervention. Methods From June 2007 to June 2008, 87 patients with stage III-IVA nasopharyngeal carcinoma who completed radical radiation therapy were enrolled prospectively. All patients underwent nasopharyngeal swabs for LMP1 prior to treatment. Results Of the 87 swab samples, LMP1 was detected in 75 (86.2%). Overall survival rates were significantly higher in patients without LMP1 expression (LMP1-) compared with those with LMP1 (LMP1+) (100% vs. 71.6%, respectively, P = 0.034). In addition, clear trends of improved regional relapsefree, distant metastasis-free and progression-free survival rates were noted in the LMP1- group compared with the LMP1+ group (P = 0.076, P = 0.067 and P = 0.058, respectively). Local control between the two groups was similar (P = 0.165). Conclusion Pre-treatment LMP1 as detected by nasopharyngeal swabs using polymerase chain reaction is an adverse prognostic factor for stage III-IVA nasopharyngeal carcinoma and potentially can be used as a treatment stratification tool.