Abstract
RATIONALE: Hormone receptor-positive, HER2-negative advanced breast cancer complicated by pulmonary lymphangitic carcinomatosis (PLC) poses significant therapeutic challenges due to the lack of standardized treatment protocols. Despite various therapeutic interventions and supportive care, prognosis remains dismal. PATIENT CONCERNS: Herein, a 48-year-old Chinese woman presented with a persistent cough, unresponsive to anti-infective treatment for 1 month. A computed tomography (CT) scan revealed lymphatic vessel infiltration and a diffuse nodular pattern, suggestive of PLC. DIAGNOSES: Hormone receptor-positive, HER2-negative advanced breast cancer complicated by PLC. INTERVENTIONS: The patient was treated with a regimen comprising low-dose apatinib, capecitabine, and albumin-bound paclitaxel. OUTCOMES: The patient achieved a partial response, with a progression-free survival exceeding beyond ten months. Symptoms of dyspnea and dry cough significantly improved, alongside a notable reduction in lymphangitic carcinomatosis. LESSONS: This case highlights the potential antitumor activity of apatinib in breast cancer patients with presenting with PLC. While further studies are necessary, this therapeutic approach could represent a viable option for managing breast cancer in the context of a visceral crisis. The case also emphasizes the importance of individualized treatment strategies and further research to substantiate these promising findings.