Palbociclib in breast cancer neoadjuvant setting

Area of Science:

• Oncology
• Medical Oncology
• Translational Research

Background:

• Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are standard treatment for hormone receptor-positive, HER2-negative metastatic breast cancer.
• Interest is growing in CDK4/6 inhibitors for adjuvant and neoadjuvant breast cancer treatment.

Observation:

• A patient initially diagnosed with stage IV luminal HER2-negative breast cancer with liver metastasis was treated with CDK4/6 inhibitors.
• Discrepant treatment response between the primary breast tumor and liver metastasis prompted a repeat liver biopsy.
• The repeat biopsy revealed a neuroendocrine tumor of unknown primary, not metastatic breast cancer.

Findings:

• The breast tumor demonstrated a partial response to CDK4/6 inhibitor therapy.
• The patient's diagnosis was revised, and the therapeutic strategy was altered for curative intent.
• This case highlights a successful application of CDK4/6 inhibitors in a neoadjuvant setting.

Implications:

• This case suggests a potential role for CDK4/6 inhibitors in neoadjuvant therapy, even in complex diagnostic scenarios.
• It underscores the importance of reassessing diagnoses when treatment responses are discordant.
• Further investigation into CDK4/6 inhibitor use in neoadjuvant and adjuvant settings for specific breast cancer subtypes is warranted.