Home / Deep Research / Triple-Negative Breast Cancer

Triple-Negative Breast Cancer

Pathophysiology description (narrative)

2026-01-24
Falcon MONDO:0005494 Model: Edison Scientific Literature 14 citations

Pathophysiology description (narrative) Triple-negative breast cancer is defined by the absence of ER, PR, and HER2 expression and accounts for about 15–20% of breast cancers. It is enriched in younger patients and in germline BRCA1 carriers, shows rapid early recurrence, and tends to metastasize viscerally. As a recent review summarized: “TNBC is characterized by its aggressive nature, limited treatment options, and poorer prognosis compared to other breast cancer subtypes,” with targeted strategies focusing on PARP inhibitors and immune checkpoint blockade but with persistent biomarker challenges (Frontiers in Oncology, 28 May 2024, https://doi.org/10.3389/fonc.2024.1405491). Mechanistically, TNBC exhibits profound genomic instability (frequent TP53 mutation; HRD in BRCA1/2 or broader HRR genes), PI3K/AKT/mTOR and EGFR pathway activation in subsets (including the luminal androgen receptor [LAR] subtype), epithelial–mesenchymal transition (EMT) and cancer stemness driving invasion and therapeutic resistance, and an often immunologically active yet variably suppressive tumor microenvironment (TME). Clinically, neoadjuvant chemotherapy remains foundational; however, residual disease after chemotherapy is common and portends high recurrence risk, underscoring the need to address EMT/stemness, DNA-repair defects, and immune evasion in combination regimens (Frontiers in Oncology, 2024; Breast Cancer: Targets and Therapy, 13 Mar 2025, https://doi.org/10.2147/bctt.s516542) (xiong2024advancementsandchallenges pages 1-2, jie2025diagnosisprognosisand pages 7-9).

Core Pathophysiology - Primary mechanisms - Homologous recombination deficiency (HRD) due to BRCA1/2 or broader HRR gene disruption creates genomic scarring, high mutation burden, and sensitivity to DNA-damaging agents (carboplatin) and PARP inhibition; HRD/TIL enrichment may also interface with ICI responsiveness (Breast Cancer: Targets and Therapy, 2025, https://doi.org/10.2147/bctt.s516542) (jie2025diagnosisprognosisand pages 7-9). - EMT and stemness: EMT programs downregulate E-cadherin and upregulate vimentin/N-cadherin, enabling motility, invasion, and resistance; EMT fosters cancer stem cell traits and post-chemotherapy minimal residual disease (Cancers, 12 Jan 2025, https://doi.org/10.3390/cancers17020228) (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - PI3K/AKT/mTOR and EGFR signaling: frequently activated in TNBC and particularly in LAR or EGFR-high tumors, promoting proliferation, survival, and metabolic reprogramming (Breast Cancer: Targets and Therapy, 2025; review of EGFR ~70% positivity in TNBC and PI3K/AKT/mTOR involvement) (jie2025diagnosisprognosisand pages 7-9). - Tumor immune microenvironment: TNBCs often show higher TILs and PD-L1 expression, supporting chemo-ICI combinations; yet ICI monotherapy responses are modest, highlighting immune evasion and need for better biomarkers (Frontiers in Oncology, 2024) (xiong2024advancementsandchallenges pages 1-2). - Dysregulated molecular pathways - DNA repair: BRCA1/2-HRD axis (jie2025diagnosisprognosisand pages 7-9). - Growth/survival: EGFR→PI3K/AKT/mTOR; FGFR4 signaling altering lipid metabolism (jie2025diagnosisprognosisand pages 7-9). - EMT networks: canonical EMT TFs/signals (e.g., TGF-β, WNT/NOTCH/Hedgehog cross-talk) highlighted in EMT-focused reviews (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Cellular processes affected - Invasion/metastasis via EMT; therapy resistance linked to EMT/stemness; metabolic rewiring to support proliferation; context-dependent immune activation/suppression influencing NAC/ICI outcomes (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2, xiong2024advancementsandchallenges pages 1-2, jie2025diagnosisprognosisand pages 7-9).

Key Molecular Players - Genes/Proteins (HGNC) - BRCA1 (HGNC:1100), BRCA2 (HGNC:1101): HRR; loss/HRD sensitizes to platinum/PARPi (jie2025diagnosisprognosisand pages 7-9). - TP53 (HGNC:11998): frequently mutated in TNBC; contributes to genomic instability (xiong2024advancementsandchallenges pages 1-2). - EGFR (HGNC:3236): overexpressed in ~70% of TNBC; activates PI3K/AKT/mTOR (jie2025diagnosisprognosisand pages 7-9). - FGFR4 (HGNC:3689): upregulated in TNBC; promotes proliferation/invasion and lipid metabolic changes (jie2025diagnosisprognosisand pages 7-9). - AR (HGNC:644): defines LAR subtype; therapeutic target under investigation (xiong2024advancementsandchallenges pages 1-2, yan2024understandingmechanismsof pages 30-35). - EMT markers/regulators: CDH1/E-cadherin (HGNC:1748) down; VIM (HGNC:12692) and CDH2/N-cadherin (HGNC:1749) up (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Chemical Entities (ChEBI) - Carboplatin (CHEBI:31355): platinum agent; higher pCR in HRD-positive TNBC (jie2025diagnosisprognosisand pages 7-9). - PARP inhibitors (class; e.g., olaparib, CHEBI:89745): effective in gBRCA-mutant TNBC (xiong2024advancementsandchallenges pages 1-2, jie2025diagnosisprognosisand pages 7-9). - Immune checkpoint inhibitors (e.g., pembrolizumab): benefit in PD-L1–positive TNBC with chemotherapy (xiong2024advancementsandchallenges pages 1-2). - Cell Types (CL) - Malignant basal-like epithelial cells (CL:0000066 derivative) exhibiting EMT/stemness (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Tumor-infiltrating lymphocytes (T cells; CL:0000084) variably abundant (xiong2024advancementsandchallenges pages 1-2). - Myeloid cells/macrophages (CL:0000235) and CAFs (CL:0000635) implicated in TME remodeling (overview) (xiong2024advancementsandchallenges pages 1-2). - Anatomical Locations (UBERON) - Mammary gland (UBERON:0001911); propensity for visceral metastases (lung UBERON:0002048; liver UBERON:0002107; brain UBERON:0000955) (xiong2024advancementsandchallenges pages 1-2).

Biological Processes (GO) disrupted - DNA repair via homologous recombination (GO:0000724) (jie2025diagnosisprognosisand pages 7-9). - Signal transduction via EGFR/PI3K/AKT (GO:0007173; GO:0043491; GO:0038083) (jie2025diagnosisprognosisand pages 7-9). - Epithelial to mesenchymal transition (GO:0001837) and regulation of cell migration (GO:0030334) (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Regulation of apoptotic process (GO:0042981) and cell cycle (GO:0051726) downstream of PI3K/AKT/EGFR (jie2025diagnosisprognosisand pages 7-9). - Immune response (GO:0006955), T cell activation (GO:0042110), and negative regulation within TME (overview) (xiong2024advancementsandchallenges pages 1-2).

Cellular Components (GO) implicated - Nucleus (GO:0005634) and DNA repair foci (GO:0035861) for HRR (jie2025diagnosisprognosisand pages 7-9). - Plasma membrane (GO:0005886) for EGFR/FGFR and AR (jie2025diagnosisprognosisand pages 7-9, xiong2024advancementsandchallenges pages 1-2). - Adherens junction (GO:0005912)/cell-cell junctions affected in EMT (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Extracellular space (GO:0005615)/ECM (GO:0031012) in invasion and CAF remodeling (overview) (xiong2024advancementsandchallenges pages 1-2).

Disease Progression (sequence) 1) Initiation: HRD/TP53 mutation and basal-like lineage programs drive genomic instability and rapid proliferation (xiong2024advancementsandchallenges pages 1-2, jie2025diagnosisprognosisand pages 7-9). 2) Local invasion: EMT program reduces E-cadherin and increases mesenchymal proteins, enabling dissemination; EGFR/PI3K signaling supports motility and survival (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2, jie2025diagnosisprognosisand pages 7-9). 3) Systemic metastasis: preferential early visceral spread; immune contexture variably hot/cold; subsets exhibit LAR signaling (xiong2024advancementsandchallenges pages 1-2). 4) Treatment response/resistance: NAC induces pCR in a subset; residual disease (RCB-II/III) common and at high recurrence risk; EMT/stemness and HRD status influence sensitivity to platinum/PARPi and to chemo-ICI combinations (błaszczak2025triplenegativebreastcancer pages 1-2, jie2025diagnosisprognosisand pages 7-9, xiong2024advancementsandchallenges pages 1-2).

Phenotypic Manifestations (HP terms) - High histologic grade and high proliferative index (Ki-67) (HP:0030079; HP:0030064) (błaszczak2025triplenegativebreastcancer pages 1-2). - Early visceral metastasis (HP:0002725 for abnormal immune response context; clinical pattern: lung/liver/brain spread) (xiong2024advancementsandchallenges pages 1-2). - Poor response durability to monotherapy ICI; improved with chemo-ICI in PD-L1+ disease (clinical phenotype) (xiong2024advancementsandchallenges pages 1-2).

Subtype and biomarker context - Transcriptomic TNBC subtypes include basal-like, immunomodulatory (IM), mesenchymal (M), and LAR; LAR tumors show AR signaling and often PI3K pathway dependence (Frontiers in Oncology, 2024; review of LAR subgroup) (xiong2024advancementsandchallenges pages 1-2, yan2024understandingmechanismsof pages 30-35). - PD-L1 and TILs are key immune biomarkers for ICI benefit; HRD/BRCA status informs platinum/PARPi sensitivity (xiong2024advancementsandchallenges pages 1-2, jie2025diagnosisprognosisand pages 7-9).

Current applications and real-world implementations - Neoadjuvant chemotherapy remains standard, with carboplatin often added in HRD-positive patients to raise pCR rates; “HRD positivity…was significantly associated with a greater pathological complete response (pCR) rate, especially in those treated with carboplatin-containing neoadjuvant regimens” (study summary in Breast Cancer: Targets and Therapy, 2025) (jie2025diagnosisprognosisand pages 7-9). - Chemo-ICI combinations (e.g., pembrolizumab plus taxane/anthracycline) improve outcomes in PD-L1–positive and early-stage settings; monotherapy ICI has modest response rates (Frontiers in Oncology, 2024) (xiong2024advancementsandchallenges pages 1-2). - Targeted strategies under study: EGFR/PI3K/AKT/mTOR inhibitors; AR antagonists for LAR; FGFR4 targeting under exploration (jie2025diagnosisprognosisand pages 7-9, xiong2024advancementsandchallenges pages 1-2).

Expert opinions and analysis (authoritative sources) - “TNBC… presents significant challenges… Targeted therapies, including PARP inhibitors, immune checkpoint inhibitors… hold promise… Challenges… include identifying novel targets, exploring combination therapies, and developing predictive biomarkers” (Frontiers in Oncology, 2024, https://doi.org/10.3389/fonc.2024.1405491) (xiong2024advancementsandchallenges pages 1-2). - EMT as a resistance driver: “Chemoresistance in TNBC is closely related to the epithelial–mesenchymal transition (EMT)… increasing metastatic potential and resistance to standard chemotherapeutic treatments” (Cancers, 2025, https://doi.org/10.3390/cancers17020228) (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Clinical course and need for precision: the 2025 clinical review emphasizes integrating biomarkers (BRCA/HRD, PD-L1) and subtyping (LAR/IM/M) to tailor therapy and monitor residual disease post-NAC (Breast Cancer: Targets and Therapy, 2025, https://doi.org/10.2147/bctt.s516542) (jie2025diagnosisprognosisand pages 7-9).

Relevant statistics and data (recent) - Proportion: TNBC represents approximately 15–20% of breast cancers; it is more common in younger and African American women and in BRCA1 mutation carriers (Frontiers in Oncology, 2024, 28 May 2024, https://doi.org/10.3389/fonc.2024.1405491) (xiong2024advancementsandchallenges pages 1-2). - Early recurrence/metastasis: TNBC shows earlier visceral relapse and poorer prognosis than other subtypes (Frontiers in Oncology, 2024) (xiong2024advancementsandchallenges pages 1-2). - Neoadjuvant outcomes and prognostics: Post-NAC residual cancer (RCB-II/III) carries a 40–80% recurrence risk; high Ki-67 associates with worse outcomes (Cancers, 12 Jan 2025, https://doi.org/10.3390/cancers17020228) (błaszczak2025triplenegativebreastcancer pages 1-2). - Survival benchmarks (clinical review synthesis): 5-year OS around 30–45% in high-risk TNBC cohorts; high risk of distant metastasis within 2 years (Breast Cancer: Targets and Therapy, 13 Mar 2025, https://doi.org/10.2147/bctt.s516542) (jie2025diagnosisprognosisand pages 7-9).

Gene/protein annotations with ontology terms (examples) - BRCA1 (HGNC:1100): DNA repair by homologous recombination (GO:0000724); nucleus (GO:0005634). Evidence: association with PARP/platinum sensitivity in TNBC review (jie2025diagnosisprognosisand pages 7-9). - BRCA2 (HGNC:1101): DNA repair by HR (GO:0000724); nucleus (GO:0005634). Evidence: as above (jie2025diagnosisprognosisand pages 7-9). - TP53 (HGNC:11998): DNA damage response (GO:0006974); regulation of cell cycle arrest (GO:0071156); nucleus (GO:0005634). Evidence: frequent TNBC mutation (xiong2024advancementsandchallenges pages 1-2). - EGFR (HGNC:3236): EGFR signaling (GO:0007173); plasma membrane (GO:0005886). Evidence: prevalent in TNBC, PI3K/AKT/mTOR activation (jie2025diagnosisprognosisand pages 7-9). - AR (HGNC:644): androgen receptor signaling pathway (GO:0030521); nucleus/cytosol (GO:0005634/GO:0005829). Evidence: LAR subtype biology (xiong2024advancementsandchallenges pages 1-2, yan2024understandingmechanismsof pages 30-35).

Phenotype associations (HP terms; examples) - HP:0030079 (High histologic grade); HP:0030064 (High Ki-67) linked to poor outcomes in TNBC (błaszczak2025triplenegativebreastcancer pages 1-2). - HP:0002715 (Recurrent infections/immune changes not directly applicable); clinically, PD-L1/TILs inform immunotherapy benefit (xiong2024advancementsandchallenges pages 1-2).

Cell type involvement (CL terms; examples) - CL:0000066 (epithelial cell) → malignant basal-like epithelium with EMT/stemness (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - CL:0000084 (T cell), CL:0000235 (macrophage), CL:0000635 (fibroblast/CAF) shape TME (overview) (xiong2024advancementsandchallenges pages 1-2).

Anatomical locations (UBERON; examples) - UBERON:0001911 (mammary gland). Common metastatic sites: UBERON:0002048 (lung), UBERON:0002107 (liver), UBERON:0000955 (brain) (xiong2024advancementsandchallenges pages 1-2).

Chemical entities (ChEBI; examples) - CHEBI:31355 (carboplatin) for HRD+ NAC; class: PARP inhibitors (e.g., olaparib CHEBI:89745) for gBRCA+ disease (jie2025diagnosisprognosisand pages 7-9, xiong2024advancementsandchallenges pages 1-2).

Evidence items with PMIDs/DOIs and direct quotes - “TNBC… poses significant challenges… Targeted therapies, including PARP inhibitors, immune checkpoint inhibitors… hold promise… [but] challenges in identifying novel targets… and developing predictive biomarkers” (Frontiers in Oncology, 28 May 2024, https://doi.org/10.3389/fonc.2024.1405491) (xiong2024advancementsandchallenges pages 1-2). - “Chemoresistance in TNBC is closely related to the epithelial–mesenchymal transition (EMT)… increasing metastatic potential and resistance to standard chemotherapeutic treatments” (Cancers, 12 Jan 2025, https://doi.org/10.3390/cancers17020228) (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Clinical course and treatment implications summarized with biomarker-driven precision (Breast Cancer: Targets and Therapy, 13 Mar 2025, https://doi.org/10.2147/bctt.s516542) (jie2025diagnosisprognosisand pages 7-9).

Recent developments (2023–2024 priority) - Consolidation of chemo-ICI regimens in early/PD-L1+ TNBC and emphasis on multi-omic biomarker development (Frontiers in Oncology, 2024) (xiong2024advancementsandchallenges pages 1-2). - HRD-guided intensification with platinum in NAC and PARP in gBRCA settings; lipid-metabolic crosstalk via FGFR4 and EGFR-PI3K axis proposed as targets (Breast Cancer: Targets and Therapy, 2025, summarizing recent studies) (jie2025diagnosisprognosisand pages 7-9).

Limitations - High-resolution single-cell and spatial TME mapping, detailed myeloid/Treg/CAF programs, and site-specific (e.g., liver) immunosuppression mechanisms are active research areas; authoritative, very recent 2024–2025 primary single-cell papers exist but were not directly accessible in the present evidence set. The conclusions above therefore emphasize robust review-level evidence available here (xiong2024advancementsandchallenges pages 1-2, jie2025diagnosisprognosisand pages 7-9) and focused EMT content (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2).

References (with URLs and dates) - Xiong N, Wu H, Yu Z. Advancements and challenges in triple-negative breast cancer: a comprehensive review of therapeutic and diagnostic strategies. Frontiers in Oncology. 28 May 2024. https://doi.org/10.3389/fonc.2024.1405491 (xiong2024advancementsandchallenges pages 1-2). - Jie H, Ma W, Huang C. Diagnosis, Prognosis, and Treatment of Triple-Negative Breast Cancer: A Review. Breast Cancer: Targets and Therapy. 13 Mar 2025. https://doi.org/10.2147/bctt.s516542 (jie2025diagnosisprognosisand pages 7-9). - Błaszczak E, et al. Triple-Negative Breast Cancer Progression and Drug Resistance in the Context of EMT. Cancers. 12 Jan 2025. https://doi.org/10.3390/cancers17020228 (błaszczak2025triplenegativebreastcancer pages 2-4, błaszczak2025triplenegativebreastcancer pages 1-2). - Yan G. Understanding Mechanisms of Oncogenesis and Identifying Markers of Drug Resistance in TNBC. 2024 (overview text) (yan2024understandingmechanismsof pages 30-35). - Malabadi RB, et al. Triple Negative Breast Cancer (TNBC): Signalling pathways—Role of plant-based inhibitors. OARJBP. 16 Mar 2024. https://doi.org/10.53022/oarjbp.2024.10.2.0013 (malabadi2024triplenegativebreast pages 1-2).

References

  1. (xiong2024advancementsandchallenges pages 1-2): Nating Xiong, Heming Wu, and Zhikang Yu. Advancements and challenges in triple-negative breast cancer: a comprehensive review of therapeutic and diagnostic strategies. Frontiers in Oncology, May 2024. URL: https://doi.org/10.3389/fonc.2024.1405491, doi:10.3389/fonc.2024.1405491. This article has 146 citations and is from a poor quality or predatory journal.

  2. (jie2025diagnosisprognosisand pages 7-9): Huan Jie, Wenhui Ma, and Cong Huang. Diagnosis, prognosis, and treatment of triple-negative breast cancer: a review. Breast Cancer : Targets and Therapy, 17:265-274, Mar 2025. URL: https://doi.org/10.2147/bctt.s516542, doi:10.2147/bctt.s516542. This article has 27 citations.

  3. (błaszczak2025triplenegativebreastcancer pages 2-4): Ewa Błaszczak, Paulina Miziak, Adrian Odrzywolski, Marzena Baran, Ewelina Gumbarewicz, and Andrzej Stepulak. Triple-negative breast cancer progression and drug resistance in the context of epithelial–mesenchymal transition. Cancers, 17:228, Jan 2025. URL: https://doi.org/10.3390/cancers17020228, doi:10.3390/cancers17020228. This article has 28 citations and is from a poor quality or predatory journal.

  4. (błaszczak2025triplenegativebreastcancer pages 1-2): Ewa Błaszczak, Paulina Miziak, Adrian Odrzywolski, Marzena Baran, Ewelina Gumbarewicz, and Andrzej Stepulak. Triple-negative breast cancer progression and drug resistance in the context of epithelial–mesenchymal transition. Cancers, 17:228, Jan 2025. URL: https://doi.org/10.3390/cancers17020228, doi:10.3390/cancers17020228. This article has 28 citations and is from a poor quality or predatory journal.

  5. (yan2024understandingmechanismsof pages 30-35): G Yan. Understanding mechanisms of oncogenesis and identifying markers of drug resistance in triple negative breast cancer. Unknown journal, 2024.

  6. (malabadi2024triplenegativebreast pages 1-2): Ravindra B. Malabadi, Sadiya MR, Kiran P. Kolkar, Simuzar S. Mammadova, Raju K. Chalannavar, Himansu Baijnath, Lavanya L, and Antonia Neidilê Ribeiro Munhoz. Triple negative breast cancer (tnbc): signalling pathways-role of plant-based inhibitors. Open Access Research Journal of Biology and Pharmacy, 10:028-071, Mar 2024. URL: https://doi.org/10.53022/oarjbp.2024.10.2.0013, doi:10.53022/oarjbp.2024.10.2.0013. This article has 32 citations.