Objective Latent membrane protein 1 (LMP1) is an oncogene of Epstein–Barr virus (EBV). Although EBV is associated with 90% of nasopharyngeal carcinoma (NPC), the reported detectable expression rates of LMP1 determined by current techniques were from 50% to 80%. This study evaluates the association of LMP1 expression with metastasis in NPC.

Methods Data from published case–control studies on LMP1 expression and metastasis in NPC were collected up to 30 March 2011. The databases of Pubmed, Medline, Embase, Chinese National Knowledge Infrastructure and the Cochrane Library were searched with keywords ‘LMP1 or latent membrane protein 1’, ‘NPC or nasopharyngeal carcinoma’ and ‘metastasis’ to identify articles published in English or Chinese. Review manager V.5.0.24 software was applied for calculating OR and corresponding 95% CI and for statistical analysis. The combined OR and 95% CI for the cumulative metastasis rate in the LMP1 expression cases versus those in the LMP1-negative cases were estimated by using fixed-effects and random-effects models.

Results 718 cases from 12 articles, including 403 cases with LMP1 expression and 315 cases without LMP1 expression, were reviewed. The cumulative metastasis rates were 66.75% (269/403) in cases with LMP1 expression and 46.98% (148/315) in those without LMP1 expression. The combined OR for the cumulative metastasis rates were 1.98 (95% CI 1.38 to 2.837) in the fixed-effects model and 2.27 (95% CI 1.10 to 4.69) in the random-effects model.

Conclusion LMP1 expression is positively associated with metastasis in NPC, thus LMP1 detection in primary NPC might be an effective and feasible means to predict metastasis.