Marie underwent breast conserving surgery, what now?

Marie, a 45-year-old married engineer and mother of 2 teenage daughters, was diagnosed with cT1cN0 breast cancer in the left breast (2 cm). She is premenopausal and has no relevant personal or family medical history.

• Tumour biopsy:
  • Invasive carcinoma of no special type
  • Scarff-Bloom-Richardson grade 2 (2 + 2 + 2)
  • ER positive (100%), PgR positive (50%), HER2 staining negative (1+), and Ki67 20%
• Initial treatment: BCS + SLNB
• Final pathology report:
  • Invasive carcinoma of no special type
  • pT1c (18 mm), pN0 (0/2 sn)
  • ER positive (80%), PgR positive (60%)
  • HER2 staining negative (1+)
  • Ki67 20%
  • No vascular or lymphatic channel invasion

The tumour board recommended an anthracycline and taxane-based adjuvant chemotherapy due to the patient’s age, tumour grade 2 and Ki67 result (20%). However, it was also recommended to perform an Oncotype DX® test, which could be of interest in this situation for de-escalation strategy. The test was performed and showed a Recurrence Score® result of 15.