Detection of the 30 base pair deletion of Epstein-Barr virus latent membrane protein 1 in extranodal nasal type NK/T-cell lymphoma and its prognostic significance

Objective To compare the detection rate of Epstein-Barr virus latent membrane protein 1 (LMP1) 30 base pair deletion in extranodal nasal type NK/T-cell lymphoma with that in chronic inflammation of nasopharynx and tonsillitis; and to analyze the prognostic significance of LMP1 deletion in extranodal nasal type NK/T-cell lymphoma.Methods Polymerase chain reaction was used to detect the deletion of LMP1 in 55 cases of extranodal nasal type NK/T-cell lymphoma and 19 cases of chronic inflammation of nasopharynx and tonsillitis.Follow-up information of 1 to 58-month duration was available in 33 patients.Results In all the 55 extranodal nasal type NK/T-cell lymphoma cases studied, 9 cases contained the wide-type or predominantly wide-type LMP1.On the other hand, 46 cases contained the deleted or predominantly deleted LMP1.In the non-lymphoma control group, 16 cases contained the deleted or predominantly deleted LMP1.However, no statistically significant difference was found in the detection rate of 30 base pair deleted LMP1 between extranodal nasal type NK/T-cell lymphoma and control group (P0.05).The prognosis of deleted or predominantly deleted LMP1 in extranodal nasal type NK/T-cell lymphoma was worse.Conclusion Though 30 base pair deletion of Epstein-Barr virus LMP1 may not be an important pathogenetic step in extranodal nasal type NK/T-cell lymphoma, it may play some role in tumor progression.