Claire has a high risk of relapse and is reluctant to chemotherapy. What to do?

Claire, a 27-year-old premenopausal woman presented with a symptomatic lump in the left breast.

Triple assessment documented a suspicious 30 mm lesion at the 6 o’clock position with normal axilla. A breast MRI confirmed a 27 mm lesion with axilla. A core diagnostic biopsy confirmed a grade 2 invasive ductal carcinoma ER 8/8, PgR 8/8, HER2 1+ on IHC. Genetic testing did not reveal BRCA1, BRCA2, PALB2 and TP53 mutations.

Following breast conserving surgery plus sentinel lymph node biopsy, on surgical specimen her disease was found to have the following characteristics:

• pT2 (23 mm)
• Grade 3 (T3 P3 M2)
• Invasive ductal carcinoma
• High grade DCIS
• No lymphovascular invasion
• Margin clear from IDC and DCIS for > 2 mm
• pN0 (0/2)
• Ki67 15%
• ER 8/8, PgR 8/8, HER2 1+

The tumour board recommended adjuvant anthracycline-based chemotherapy due to very young age and grade 3, followed by radiotherapy and endocrine therapy. Nonetheless, since the patient was reluctant to consider chemotherapy, the Oncotype DX® assay was performed and showed a Recurrence Score® result of 25.