Sacituzumab govitecan combined with anlotinib in metastatic triple negative breast cancer patient with repeated pleural effusion: a case report.

Metastatic triple-negative breast cancer (mTNBC) is an aggressive malignancy with limited targeted therapeutic alternatives and dismal long-term prognosis. Sacituzumab govitecan (SG) is a Trop-2-directed antibody-drug conjugate (ADC) conjugated to the topoisomerase I inhibitor SN-38. SG has demonstrated robust anti-tumor activity across multiple clinical trials for mTNBC. We present a hypothesis-generating case report of a 50-year-old female patient with stage III triple-negative breast cancer (TNBC) who received curative-intent surgery followed by adjuvant multimodal therapy. Fourteen months after completing adjuvant treatment, the patient developed bone-only recurrence and received local bone radiotherapy plus first-line albumin-bound paclitaxel plus carboplatin chemotherapy, followed by capecitabine maintenance until 25 April 2023. Upon successive systemic disease progression, the patient sequentially received second-line toripalimab plus gemcitabine and third-line toripalimab plus eribulin through November 2023. Cervical lymph node biopsy confirmed metastatic TNBC with negative BRCA germline status and PD-L1 tumor proportion score (TPS) < 1%. Per international and domestic clinical guidelines, single-agent SG (10 mg/kg) was initiated as fourth-line therapy. During SG monotherapy, recurrent symptomatic malignant pleural effusion developed, and oral anlotinib 10 mg (days 1-14 every 21-day cycle) was added to the treatment regimen starting 18 July 2024. As of 4 February 2025, the patient completed 7 cycles of SG monotherapy and 9 cycles of sequential SG plus anlotinib combination treatment. Clinically, no recurrent pleural effusion was observed after anlotinib initiation; measurable pulmonary, hepatic, and cervical nodal metastases exhibited sustained shrinkage alongside declining serum tumor markers, yielding a 12-month progression-free survival (PFS). Grade 1-2 treatment-emergent adverse events included leukopenia, neutropenia, diarrhea, and fatigue, all manageable with supportive care. To our knowledge, this is the first descriptive case documenting sustained disease control following SG plus anlotinib combination in heavily pretreated mTNBC complicated by recurrent malignant pleural effusion. It should also be noted that although the timing of clinical symptom improvement coincided with the initiation of anlotinib, this single case cannot differentiate whether the clinical benefit observed derived from the potential synergistic effect of the two agents or the monotherapeutic effect of anlotinib alone. Without validation from phase II/III prospective clinical trials, this case only generates a preliminary hypothesis that SG combined with anlotinib may represent a potential salvage therapeutic strategy for heavily pretreated advanced TNBC patients complicated by refractory malignant pleural effusion or localized progression under single-agent SG. Further prospective clinical research is required to verify the synergistic activity of this regimen.