Asian Journal of Oncology (Jan 2020)

A Retrospective, Observational Study to Determine the Patient and Tumor Characteristics of HER2-Positive Breast Cancer Patients Treated at Five Main Public Cancer Centers in Malaysia

  • Ros Suzanna Ahmad Bustamam,
  • Yu Kong Leong,
  • Flora Li Tze Chong,
  • Florence Wong Yoke Fui,
  • Yew-Teik Cheong,
  • Goh Kenny

DOI
https://doi.org/10.1055/s-0040-1708108
Journal volume & issue
Vol. 6, no. 01
pp. 10 – 19

Abstract

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Introduction Human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer is a high-risk subtype with poor prognosis. The incidence of HER2 expressing tumors is high in Malaysia; however, there is limited information on the characteristics of these tumors. Therefore, we sought to collect the patient and tumor characteristics of HER2+ breast cancer cases at five centers in Malaysia. Patients and Methods A retrospective review was conducted of the data from charts of patients diagnosed with HER2+ breast cancer between January 2014 and December 2015 at Hospital Kuala Lumpur, Institute Kanser Negara, Hospital Pulau Pinang, Hospital Besar Sarawak, and Hospital Likas in Malaysia. Results Of the 1,519 screened patient’ charts, 396 were included for the analysis. The average age of HER2+ breast cancer cases at diagnosis was 51.07 years. A high percentage of cases presented at an advanced stage (38.89 and 12.12% with stage 3 and 4, respectively). About 58.84% of patients were categorized as “high-risk,” with one or more lymph node involvement. Close to half (47.98%) of cases presented with T2 stage tumors, and infiltrating ductal carcinomas were reported in 85.35% of tumors. The most common immunohistochemical subtype was estrogen receptor (ER)+/progesterone receptor (PR)+/HER2+ (47.47%), followed by ER–/PR–/HER2+ (37.12%). Conclusion HER2 overexpressing tumors represent an aggressive subtype in Malaysia with large tumor size, high tumor grade, and lymph node involvement. Early diagnosis and management of these tumors may help improve the survival rates. Future studies should help elucidate the treatment patterns and outcomes in HER2+ breast cancer patients in Malaysia.

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