MET amplification is not rare and predicts unfavorable clinical outcomes in patients with recurrent/metastatic gastric cancer after chemotherapy

Authors

  • Xin An MD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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    • The first 2 authors contributed equally to this work.

  • Fang Wang MD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Molecular Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China
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    • The first 2 authors contributed equally to this work.

  • Qiong Shao MD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Molecular Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Feng-Hua Wang MD, PhD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Zhi-Qiang Wang MD, PhD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Cui Chen MD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Cong Li MD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Hui-Yan Luo MD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Dong-Sheng Zhang MD, PhD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Rui-Hua Xu MD, PhD,

    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
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  • Yu-Hong Li MD, PhD

    Corresponding author
    1. State Key Laboratory of Oncology in South China, Guangzhou, China
    2. Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
    • Corresponding author: Yu-Hong Li, MD, PhD, Department of Medical Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng East Rd, Guangzhou, China 510060; Fax: (011) 86-20-87343535; liyh@sysucc.org.cn

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Abstract

BACKGROUND

Several large studies have reported an extremely low incidence of MET gene amplification (GA) in patients with radically resected gastric cancer. This study was conducted to evaluate the prevalence and prognostic role of MET in patients with recurrent/metastatic gastric cancer who received chemotherapy.

METHODS

MET GA and protein expression of recurrent/metastatic gastric cancer samples were evaluated by fluorescence in situ hybridization and immunohistochemistry (IHC), respectively.

RESULTS

This retrospective study included 232 patients with recurrent/metastatic gastric cancer. MET GA and strong protein expression (IHC3+) were observed in 8.3% (19 of 230 samples) and 9.6% (22 of 229 samples) of samples, respectively. A significant correlation was observed between MET GA and protein expression (r = 0.378; P < .001). MET GA was correlated with poor performance status (P < .001) and poorly differentiated tumors (P = .0015). Both MET GA and IHC 3+ expression were associated with a substantially shorter median overall survival (OS) and progression-free survival (PFS). The median OS and PFS for patients with MET GA versus those without MET GA were 5.7 months versus 15.5 months (P < .001) and 3.6 months versus 6.9 months (P < .001), respectively. The median OS and PFS for patients with MET IHC 3+ expression versus IHC 0 to 2+ expression were 6.3 months versus 15.1 months (P < .001) and 3.6 months versus 7.0 months (P < .001), respectively.

CONCLUSIONS

In patients with recurrent/metastatic gastric cancer, MET amplification and strong protein expression are not rare and appear to be significantly associated with unfavorable clinical outcomes. Cancer 2014;120:675–682. © 2013 American Cancer Society.

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