Roundtable Roundup: ER+/PR+, HER2– Breast Cancer

CASE SUMMARY

Initial presentation:

• A 56-year-old, postmenopausal woman presented with a palpable right breast mass with no clinically abnormal axillary lymph nodes.
• Core biopsy: grade II invasive ductal carcinoma (IDC), estrogen receptor positive (ER+)/progesterone receptor positive (PR+), HER2 immunohistochemistry (IHC) score of 0, Ki-67 33%
• Lumpectomy and sentinel lymph node (SLN) biopsy: 3.0 cm, grade 2 IDC, 2 SLN negative for malignant cells
• 21-gene recurrence score: 27
• She received 4 cycles of docetaxel and cyclophosphamide followed by radiation therapy and completed 5 years of adjuvant aromatase inhibitor (AI).

Three years later:

• The patient reported right-sided abdominal pain and mild nausea.
• CT scan of the chest/abdomen/pelvis showed 3 suspicious liver lesions (right lobe, largest 2 cm).
• Liver biopsy showed adenocarcinoma consistent with breast primary.
  • ER+/PR+, HER2 IHC 0
• Liver function test: within normal limits.
• Comprehensive molecular testing from tissue biopsy showed no actionable alterations.
• AI plus palbociclib (Ibrance) was initiated. Response: Therapy tolerated well with grade 2 neutropenia that did not require dose modification of palbociclib.

Twenty months later:

• Follow-up imaging showed increased size of both liver nodules and 2 new lung nodules, the largest measuring 0.9 cm.
• Her ECOG performance status was 0 and her liver enzymes were normal.