The 30-bp Deletion of Epstein-Barr Virus Latent Membrane Protein-1 Gene Has No Effect in Nasopharyngeal Carcinoma

Authors

  • Kai-Ping Chang MD,

    1. Department of Otolaryngology–Head & Neck Surgery, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
    2. Department of Radiation Oncology, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
    3. Graduate Institute of Clinical Medical Sciences, Chang Gung University, Kwei-Shan, Taoyuan, Taiwan
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  • Sheng-Po Hao MD, FACS, FICS,

    1. Department of Otolaryngology–Head & Neck Surgery, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
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  • Shinn-Yn Lin MD,

    1. Department of Otolaryngology–Head & Neck Surgery, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
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  • Shir-Hwa Ueng MD,

    1. Department of Radiation Oncology, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
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  • Ping-Ching Pai MD,

    1. Graduate Institute of Clinical Medical Sciences, Chang Gung University, Kwei-Shan, Taoyuan, Taiwan
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  • Chen-Kan Tseng MD,

    1. Graduate Institute of Clinical Medical Sciences, Chang Gung University, Kwei-Shan, Taoyuan, Taiwan
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  • Chuen Hsueh MD,

    1. Department of Pathology, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
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  • Meng-Shu Hsieh MD, MPH,

    1. Department of Family Medicine, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
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  • Jau-Song Yu PhD,

    1. Head & Neck Oncology (II), Chang Gung Cancer Center, Kwei-Shan, Taoyuan, Taiwan
    2. Graduate Institute of Basic Medical Sciences, Chang Gung University, Kwei-Shan, Taoyuan, Taiwan
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  • Ngan-Ming Tsang MD, DSc

    Corresponding author
    1. Department of Radiation Oncology, Chang Gung Memorial Hospital, Kwei-Shan, Taoyuan, Taiwan
    • Dr. Ngan-Ming Tsang, Department of Radiation Oncology, Chang Gung Memorial Hospital, 5 Fu-Shin Street, Kwei-Shan, Taoyuan, Taiwan
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  • This study was supported by grants from the Taiwan National Science Council (NSC88-2314-B-182A-010, NSC92-2314-B-182A-207) and Chang Gung University (CMRPG32077, CMRPG32090).

Abstract

Objective: The specific 30-bp deletion of the Epstein-Barr virus (EBV)-derived latent membrane protein-1 gene has been suggested to be associated with the pathogenesis of nasopharyngeal carcinoma (NPC) and a more aggressive phenotype of some EBV-associated malignancies.

Methods: The authors conducted a retrospective cohort study. Between 1995 and 2001, 542 patients who had received complete courses of radiotherapy followed by at least 3 years of follow up were enrolled. Patients were divided into two groups according to the presence or absence of the 30-bp deletion in their tumor samples.

Results: A total of 446 (82.3%) patients were found to feature the 30-bp deletion, whereas 88 (16.2%) did not. Interestingly, dual infection was found in eight (1.5%) patients. No statistical significance was found in age, gender, NPC-presenting stage, radiosensitivity, and pathologic classification between the two groups. The actuarial 5-year overall survival rate and the distant metastasis-free rate for the 30-bp deletion and nondeletion group were not statistically different (61.3% vs. 65.4% and 68.1% vs. 73.1%; P = .132 and .135, respectively). In multivariate analysis, older age, nasopharyngeal recurrence, advanced tumor stage, and the development of distant metastasis were shown to be poorer prognosticators for overall survival, whereas the presence of 30-bp deletion was not. For distant metastasis, only advanced tumor stage was shown to be a poor prognosticator, whereas other variables, including the presence of 30-bp deletion, had no statistical significance.

Conclusions: In this retrospective cohort, we have demonstrated that this specific 30-bp sequence deletion might be only the predominant variant rather than an NPC phenotype-associated polymorphism. Additionally, dual infection is a rare but possible phenomenon in the endemic NPC tumors.

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