RT Journal Article T1 The Evolution of Clinically Aggressive Triple-Negative Breast Cancer Shows a Large Mutational Diversity and Early Metastasis to Lymph Nodes A1 Martinez-Gregorio, Hector A1 Rojas-Jimenez, Ernesto A1 Cesar Mejia-Gomez, Javier A1 Diaz-Velasquez, Clara A1 Quezada-Urban, Rosalia A1 Vallejo-Lecuona, Fernando A1 de la Cruz-Montoya, Aldo A1 Iris Porras-Reyes, Fany A1 Manuel Perez-Sanchez, Victor A1 Aquiles Maldonado-Martinez, Hector A1 Robles-Estrada, Maybelline A1 Bargallo-Rocha, Enrique A1 Cabrera-Galeana, Paula A1 Ramos-Ramirez, Maritza A1 Irasema Chirino, Yolanda A1 Alonso Herrera, Luis A1 Ignacio Terrazas, Luis A1 Frecha, Cecilia A1 Oliver, Javier A1 Perdomo, Sandra A1 Vaca-Paniagua, Felipe K1 triple-negative breast cancer K1 tumor evolution K1 metastasis K1 lymph nodes K1 early divergence K1 targeted therapies K1 Genomic characterization K1 Signatures K1 Insights K1 Tumor K1 Landscape K1 History AB Simple Summary: Triple-negative breast cancer (TNBC) is a clinically, phenotypically, and molecularly heterogeneous disease. This heterogeneity is a factor that negatively impacts therapy response. To analyze evolutionary patterns and the genomic alterations in patients with clinically aggressive disease who did not respond to treatment, we performed whole-exome sequencing in multiple longitudinal samples from diagnosis to distant metastasis. We found an extensive intrapatient and interpatient genetic heterogeneity, mutational signature composition at different stages, and, interestingly, an early lymph node metastasis formation during the evolution of aggressive TNBC. This study provides detailed insights into the genomic complexity, and the phylogenetic and evolutionary development of TNBC, as well as identifying specific mutations associated with targeted treatments in TNBC.In triple-negative breast cancer (TNBC), only 30% of patients treated with neoadjuvant chemotherapy achieve a pathological complete response after treatment and more than 90% die due to metastasis formation. The diverse clinical responses and metastatic developments are attributed to extensive intrapatient genetic heterogeneity and tumor evolution acting on this neoplasm. In this work, we aimed to evaluate genomic alterations and tumor evolution in TNBC patients with aggressive disease. We sequenced the whole exome of 16 lesions from four patients who did not respond to therapy, and took several follow-up samples, including samples from tumors before and after treatment, as well as from the lymph nodes and skin metastases. We found substantial intrapatient genetic heterogeneity, with a variable tumor mutational composition. Early truncal events were MCL1 amplifications. Metastatic lesions had deletions in RB1 and PTEN, along with TERT, AKT2, and CCNE1 amplifications. Mutational signatures 06 and 12 were mainly detected in skin metastases and lymph nodes. According to phylogenetic analysis, the lymph node metastases occurred at an early stage of TNBC development. Finally, each patient had three to eight candidate driving mutations for targeted treatments. This study delves into the genomic complexity and the phylogenetic and evolutionary development of aggressive TNBC, supporting early metastatic development, and identifies specific genetic alterations associated with a response to targeted therapies. PB Mdpi YR 2021 FD 2021-10-01 LK https://hdl.handle.net/10668/24574 UL https://hdl.handle.net/10668/24574 LA en DS RISalud RD Apr 17, 2025