Migracytosis and angiogenesis were crucial in breast cancer (BRCA) progression. This study aimed to develop a prognostic signature based on migracytosis- and angiogenesis-related lncRNAs. All genetic and clinical data of BRCA were acquired from The Cancer Genome Atlas (TCGA) database. A prognostic signature consisting of six lncRNAs (YTHDF3-AS1, AC018445.5, AP005131.1, AC010531.3, MIR200CHG, and AC000067.1) was established through correlation and Cox regression analysis, as well as the least absolute shrinkage and selection operator (LASSO) test. The BRCA patients from TCGA were categorized into high-risk and low-risk subgroups. Nomograms, calibration plots, Kaplan-Meier survival curves, and receiver operating characteristic (ROC) curves were used to evaluate the overall survival (OS) and predictive value of the signature. To explore the biological functions of migracytosis- and angiogenesis-related lncRNAs, enrichment analysis, tumor mutation burden (TMB), and the ESTIMATE algorithm were performed. Additionally, consensus clustering was applied to categorize tumor subtypes, and the disparity among all clusters was assessed, including drug sensitivity and immunotherapeutic efficacy. The expression levels of prognostic lncRNAs were validated using RT-PCR, while their functional impact on cell proliferation was assessed via the Cell Counting Kit-8 (CCK-8) assay in vitro. The results indicated that patients in the high-risk subgroup had a worse prognosis, higher TMB, stronger immune response, and greater sensitivity to immunotherapy. In summary, the prognostic risk signature based on migracytosis- and angiogenesis-related lncRNAs was associated with the clinical prognosis of BRCA patients. The signature's risk score could potentially be used to predict clinical classification and therapeutic efficacy.