Related Experiment Video
Updated: Jan 13, 2026

Modeling Breast Cancer via an Intraductal Injection of Cre-expressing Adenovirus into the Mouse Mammary Gland
Published on: June 7, 2019
Introducing a New Hypothesis in the Genesis of Breast Cancer: An Integrative Review
Jan Pawel Andrade Pachnicki1,2,3,4, Clara Marie Cayet1, Diego Akyo Hoshina Dos Santos1
1School of Medicine, Positivo University, Curitiba, Paraná, Brazil.
Introduction:
Breast cancer is the second most common cancer among women worldwide. Estrogen is currently identified as one of the main agents involved in the initiation of breast tumors; however, evidence indicates a greater risk when estrogen replacement is combined with progesterone, whereas its isolated use does not represent a significant risk. Inconsistencies in existing theories highlight the need for further detailed research on the relationship between hormone exposure and breast tumorigenesis, with particular emphasis on fibrinogen and its components in the context of this review.
Objective:
Introduce a new theory into the medical literature concerning the genesis of breast cancer.
Methods:
This is an integrative literature review based on a selection of relevant articles published between 2000 and 2025, in both Portuguese and English, and sourced from the following databases: Scielo, ScienceDirect, National Library of Medicine, PubMed, Cochrane, Brazilian Journal of Development, and ResearchGate.
Results:
Fifty-six references were selected to support the development of the discussion components, which are subdivided into the following themes: physiology of estrogen and progesterone in the body, actions of hormonal therapies, both combined and isolated, in breast cancer, and fibrinolytic physiology.
Conclusion:
After identifying contradictions in current theories about the influence of estrogen on tumor proliferation, which encouraged the search for new interpretations, it was demonstrated that free estrogen and its by-products, such as fibrinogen-related protein (fibrinogen-like protein 1 and 2), play a role in the immune system's failure to contain malignant cells, opening another field of therapeutic research for breast cancer.
More Related Videos
06:36A Modified In vitro Invasion Assay to Determine the Potential Role of Hormones, Cytokines and/or Growth Factors in Mediating Cancer Cell Invasion
Published on: April 24, 2015
05:02Modeling Brain Metastasis Via Tail-Vein Injection of Inflammatory Breast Cancer Cells
Published on: February 4, 2021
Related Concept Videos
Activation of Integrins
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding...
Adaptive Mechanisms in Cancer Cells
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
Cancers Originate from Somatic Mutations in a Single Cell
The Nucleolus
Cancer-Critical Genes I: Proto-oncogenes
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
Integrins
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...