OncoTargets and Therapy (Oct 2017)

Molecular alterations and clinical prognostic factors for cholangiocarcinoma in Thai population

  • Trachu N,
  • Sirachainan E,
  • Larbcharoensub N,
  • Rattanadech W,
  • Detarkom S,
  • Monnamo N,
  • Kamprerasart K,
  • MunTham D,
  • Sukasem C,
  • Reungwetwattana T

Journal volume & issue
Vol. Volume 10
pp. 4955 – 4968

Abstract

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N Trachu,1,2 E Sirachainan,3 N Larbcharoensub,4 W Rattanadech,3 S Detarkom,3 N Monnamo,1 K Kamprerasart,4 D MunTham,5 C Sukasem,6,7 T Reungwetwattana3 1Research Center, Faculty of Medicine Ramathibodi Hospital, 2Molecular Medicine Program, Multidisciplinary Unit, Faculty of Science, 3Division of Medical Oncology, Department of Medicine, 4Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 5Section for Mathematic, Faculty of Science and Technology, Rajamangala University of Technology Suvarnabhumi, 6Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, 7Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Abstract: This study explores genomic alterations in cholangiocarcinoma (CCC) tissues in Thai patients. We identified and reviewed the records of patients who had been diagnosed with CCC and for whom sufficient tumor samples for DNA and RNA extraction were available in our database. The specimens were explored for EGFR, KRAS, BRAF, and PIK3CA mutations and ROS1 translocation in 81 samples. Immunohistochemistry staining for HER2, ALK, and Ki-67 expression was tested in 74 samples. Prevalence of EGFR, KRAS, and PIK3CA mutations in this study was 21%, 12%, and 16%, respectively. No BRAF V600 mutation or ROS1 translocation was found. Patients with T790M mutation had a significantly longer overall survival (18.84 months) than those with the other types of EGFR mutations (4.08  months; hazard ratio [HR]: 0.26, P=0.038) and also had a significantly lower median Ki-67 (22.5% vs 80%, P=0.025). Furthermore, patients with PIK3CA mutations had a significantly longer median progression-free survival (15.87 vs 7.01 months; HR: 0.46, P=0.043). Strongly positive HER2 expression was found in only 1 patient, whereas ALK expression was not found. The presence of EGFR and/or PIK3CA mutations implies that targeted drugs may provide a feasible CCC treatment in the future. Keywords: cholangiocarcinoma, targeted therapy, gene alterations

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