What is the clinical evidence for a 70-year-old female with Estrogen Receptor positive (ER+) Invasive Ductal Carcinoma (IDC) recurrence in the axillary lymph node to receive neoadjuvant endocrine therapy?

Neoadjuvant Endocrine Therapy for 70-Year-Old Female with ER+ IDC Recurrence in Axillary Lymph Node

Neoadjuvant endocrine therapy is an appropriate treatment option for a 70-year-old female with ER+ IDC recurrence in axillary lymph node, with aromatase inhibitors being the preferred agents in this postmenopausal population. 1, 2

Evidence for Neoadjuvant Endocrine Therapy in Older Patients

Efficacy and Rationale

• For postmenopausal women with ER+ breast cancer, aromatase inhibitors (anastrozole, letrozole, or exemestane) are recommended as the primary endocrine therapy option 2
• Limited data are available for making chemotherapy recommendations for patients older than 70 years, and treatment should be individualized with consideration of comorbid conditions 1
• The NCCN guidelines specifically state that endocrine therapy alone may be considered for receptor-positive disease in postmenopausal patients as neoadjuvant therapy 1

Axillary Response Rates

• Recent data from the National Cancer Database analysis showed that 14.48% of patients with node-positive, ER+, HER2- breast cancer achieved axillary pathologic complete response (pCR) after neoadjuvant endocrine therapy 3
• However, a smaller study found that downstaging of the axilla was unsuccessful in the majority of patients, with only 3% achieving axillary pCR 4

Treatment Algorithm for 70-Year-Old Female with ER+ Axillary Recurrence

1. Initial Assessment:

   • Confirm ER+ status and HER2 status
   • Complete staging workup including bilateral mammogram, breast MRI, and systemic imaging to rule out distant metastases 1
   • Consider genomic assays if available to assess tumor biology

2. Neoadjuvant Endocrine Therapy:

   • First choice: Aromatase inhibitor (letrozole, anastrozole, or exemestane) for 4-6 months 2
   • Monitor clinical response every 2-3 months with physical examination
   • Consider imaging assessment (breast MRI) at baseline, interim (8-16 weeks), and preoperative timepoints 5

3. Response Assessment and Surgical Planning:

   • Complete response: Consider breast-conserving surgery with sentinel lymph node biopsy (SLNB) 1
   • Partial response with lumpectomy possible: Proceed with lumpectomy 1
   • Partial response with lumpectomy not possible: Consider mastectomy 1
   • No response after 3-4 months or progressive disease: Consider alternative therapy including chemotherapy or proceed directly to surgery 1

4. Axillary Management:

   • For clinically persistent axillary disease after NET: Axillary lymph node dissection (ALND) 1
   • For clinically negative axilla after NET: Consider SLNB with frozen section 4
   • If SLNB positive: Complete ALND 1

Important Considerations and Caveats

• Axillary assessment: MRI assessment of axillary nodes during NET has shown positive correlation with pathologic findings, but is not completely sufficient to preclude surgical axillary staging 5

• Response rates: Axillary pCR rates with NET (3-14%) are lower than those typically seen with neoadjuvant chemotherapy, which should be considered in surgical planning 4, 3

• Duration of therapy: Optimal duration of neoadjuvant endocrine therapy is not well established, but 4-6 months is commonly used to allow for maximum response 1

• Age considerations: For patients >70 years old, the NCCN guidelines specifically note that limited data are available to make chemotherapy recommendations, making endocrine therapy an attractive option 1

• Pitfall to avoid: Do not rely solely on clinical or radiological assessment of axillary response, as studies show that imaging may both over and underestimate residual nodal disease 5

• Post-surgical therapy: Following surgery, adjuvant endocrine therapy should be continued for a total of 5 years or more 6

In summary, neoadjuvant endocrine therapy represents a reasonable approach for a 70-year-old female with ER+ IDC recurrence in axillary lymph node, particularly when considering the potential toxicities of chemotherapy in this age group. While axillary pCR rates are modest, the treatment can facilitate surgical planning and provide important prognostic information while avoiding the toxicities associated with chemotherapy.