Application of neoadjuvant chemotherapy combined with anlotinib in occult breast cancer: A case report and review of literature

BACKGROUND Occult breast cancer (OBC) is a special type of breast cancer presenting as axillary lymph node metastasis with undetectable primary lesions in the breast. Due to its low incidence and unique clinical manifestations, there is a lack of consensus on the diagnosis and treatment of OBC. We report a case of OBC treated with neoadjuvant chemotherapy combined with anlotinib. The treatment was well tolerated, and the patient achieved a pathologic complete response. CASE SUMMARY A 53-year-old woman presented with a lump in her right axillary area with no primary lesions in the breast. Pathological biopsy confirmed right axillary metastatic carcinoma. Immunohistochemical staining results were positive for progesterone receptor, cytokeratin 7, specific breast markers GATA3 and gross cystic disease fluid protein-15. Tumor cells were negative for estrogen receptor, human epidermal growth factor receptor-2, cytokeratin 5/6, cytokeratin 20, and villin. The patient was diagnosed with OBC, and she underwent neoadjuvant chemotherapy combined with anlotinib. Mastectomy plus axillary lymph node dissection was performed. The patient achieved pathologic complete response with no residual invasive tumor cells in the breast or axillary lymph nodes. Postoperatively, she received adjuvant radiotherapy and endocrine therapy. CONCLUSION Neoadjuvant chemotherapy and anlotinib had good efficacy and safety in the treatment of OBC and may be a new therapeutic option.