Therapeutic landscape of metaplastic breast cancer

Cancer Treat Rev. 2019 Sep:79:101888. doi: 10.1016/j.ctrv.2019.08.004. Epub 2019 Aug 13.


Metaplastic breast carcinomas (MPBC) are rare, aggressive and relatively chemorefractory tumors with a high unmet need. While most are "triple negative" and lack expression of estrogen, progesterone and HER2 receptors, MPBC are associated with worse outcomes compared to conventional triple negative invasive tumors. MPBCs are genetically heterogeneous and harbor somatic mutations, most frequently in TP53, PIK3CA and PTEN, with emerging studies suggesting a role for novel targeted therapies. These tumors have also been associated with overexpression of PD-L1 and tumor-infiltrating lymphocytes suggesting an endogenous immune response and therefore a rationale for treatment with immunotherapies. Here, we focus on therapeutic options for this difficult to treat breast cancer subtype and encourage physicians to consider targeted therapies/immunotherapies as part of ongoing clinical trials.

Keywords: Immunotherapies; Metaplastic breast cancer; Targeted therapies; Triple negative breast cancer.

Publication types

  • Review

MeSH terms

  • Animals
  • Biomarkers, Tumor
  • Breast Neoplasms / etiology
  • Breast Neoplasms / mortality
  • Breast Neoplasms / pathology*
  • Breast Neoplasms / therapy*
  • Clinical Trials as Topic
  • Combined Modality Therapy / methods
  • Disease Management
  • Epithelial-Mesenchymal Transition
  • Female
  • Genetic Variation
  • Humans
  • Neoplasm Staging
  • Neoplastic Stem Cells / metabolism
  • Treatment Outcome


  • Biomarkers, Tumor