Cancer Management and Research (Jun 2019)

The prognosis comparison of different molecular subtypes of breast tumors after radiotherapy and the intrinsic reasons for their distinct radiosensitivity

  • He L,
  • Lv Y,
  • Song Y,
  • Zhang B

Journal volume & issue
Vol. Volume 11
pp. 5765 – 5775

Abstract

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Lin He,1 Yang Lv,2 Yuhua Song,1 Biyuan Zhang31Breast Center B Ward, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, People’s Republic of China; 2Department of Oncology, The PLA Navy Anqing Hospital, Anqing, Anhui Province, People’s Republic of China; 3Department of Radiotherapy, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, People’s Republic of ChinaAbstract: Radiotherapy can increase the cell cycle arrest that promotes apoptosis, reduces the risk of tumor recurrence and has become an irreplaceable component of systematic treatment for patients with breast cancer. Substantial advances in precise radiotherapy unequivocally indicate that the benefits of radiotherapy vary depending on intrinsic subtypes of the disease; luminal A breast cancer has the highest benefit whereas human epidermal growth factor receptor 2 (HER2)-positive and triple negative breast cancer (TNBC) are affected to a lesser extent irrespective of the selection of radiotherapy strategies, such as conventional whole-breast irradiation (CWBI), accelerated partial-breast irradiation (APBI), and hypofractionated whole-breast irradiation (HWBI). The benefit disparity correlates with the differential invasiveness, malignance, and radiosensitivity of the subtypes. A combination of a number of molecular mechanisms leads to the strong radioresistant profile of HER2-positive breast cancer, and sensitization to irradiation can be induced by multiple drugs or compounds in luminal disease and TNBC. In this review, we aimed to summarize the prognostic differences between various subtypes of breast tumors after CWBI, APBI, and HWBI, the potential reasons for drug-enhanced radiosensitivity in luminal breast tumors and TNBC, and the robust radioresistance of HER2-positive cancer.Keywords: radiotherapy, molecular subtype, breast cancer, molecular mechanism, radiosensitivity

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