Breast cancer
CDK4/6 inhibitors for everyone? Treatment strategies in HR+ HER2- advanced breast cancer

Louisa (58 years old)

Louisa, a 58-year-old interior decorator, was diagnosed with primary metastatic breast cancer 17 months ago.

Assessment summary:

  • Postmenopausal
  • No relevant medical history, ECOG PS: 0
  • No family history of breast cancer
  • Diagnosed with primary metastatic breast cancer 17 months ago
  • Imaging:
    • 5 cm tumour in the right breast, 4 suspicious axillary lymph nodes
    • Multiple suspicious lesions in bones and pleura
  • Tumour biology: NST, ER 90%, PgR 70%, HER2 IHC 0, G2

Treatment with letrozole and CDK4/6i was started 1 month after diagnosis, which resulted in regression of bone and pleural metastases 5 months later and stable disease after 6 additional months.

Again 5 months later, i.e. 16 months after the start with letrozole and CDK4/6i:

  • Imaging:
    • Pleura: stable disease, bones: progression, new liver metastasis
  • Biopsy of liver metastasis: ER 70%, PgR 40%, HER2 IHC 0, G2
  • Somatic PIK3CA mutation status: PIK3CA mutation
  • Germline BRCA mutation status: wild type

Which option would you choose for this patient?