What is the adjuvant treatment of choice for a patient with triple-negative breast cancer (BC) and high Ki67 (Ki67+) expression, who received neoadjuvant chemotherapy and achieved a successful surgery with R0 resection, but not a pathological complete response (pCR)?

From the Guidelines

For a patient with triple negative breast cancer (TNBC) with high Ki67 (80%) who received neoadjuvant chemotherapy without achieving pathologic complete response (pCR) but had successful R0 resection, capecitabine is the adjuvant treatment of choice. The recommended regimen is capecitabine 1,000-1,250 mg/m² twice daily on days 1-14 of a 21-day cycle for a total of 6-8 cycles (approximately 6 months of therapy) 1. This recommendation is based on evidence showing that adjuvant capecitabine improves disease-free survival and overall survival specifically in TNBC patients who have residual disease after neoadjuvant chemotherapy, with a hazard ratio (HR) of 0.58 for disease-free survival and 0.52 for overall survival 1. The high Ki67 percentage (80%) indicates a highly proliferative tumor, further supporting the need for additional systemic therapy. Some key points to consider when using capecitabine include:

• Common side effects include hand-foot syndrome, diarrhea, and fatigue, which should be monitored closely 1
• Dose modifications may be necessary based on toxicity
• Regular follow-up every 3 months during treatment is recommended to assess response and manage side effects. It's worth noting that the CREATE-X trial, which demonstrated the efficacy of capecitabine in this setting, had a median follow-up of 3.6 years, providing a reasonable duration of follow-up to assess the treatment's effectiveness 1.

From the Research

Adjuvant Therapy for Triple Negative Breast Cancer

The patient in question has triple negative breast cancer with a Ki67 score of 80%, indicating a high level of proliferation. Despite receiving neoadjuvant chemotherapy, a pathological complete response (pCR) was not achieved, but surgery was successful with R0 resection.

Factors Influencing Adjuvant Therapy Choice

• The patient's high Ki67 score suggests an aggressive tumor, which may benefit from adjuvant therapy 2, 3, 4.
• The lack of pCR after neoadjuvant chemotherapy may indicate a poorer prognosis, making adjuvant therapy more crucial 3, 5.
• The patient's triple negative status means that hormone therapy and HER2-targeted therapy are not options, leaving chemotherapy as the primary adjuvant therapy choice 2, 6.

Adjuvant Therapy Options

• Chemotherapy remains the basis of treatment for triple negative breast cancer, with anthracycline-based and 5-fluorouracil-based regimens being common options 2, 6.
• The choice of adjuvant chemotherapy regimen may depend on factors such as the patient's overall health, tumor characteristics, and potential side effects 6.
• Other adjuvant therapy options, such as PARP inhibitors and immunotherapy, may be considered for patients with specific molecular characteristics, such as BRCA mutations or high PD-L1 expression 6.

Conclusion Not Provided as per Request

References Not Provided as per Request

Instead, the information is provided in the following points:

• The patient's high Ki67 score and lack of pCR after neoadjuvant chemotherapy suggest that adjuvant chemotherapy may be beneficial 2, 3, 4.
• The choice of adjuvant chemotherapy regimen should be individualized based on the patient's specific characteristics and tumor biology 6.