Cancer / Oncology/PR+ breast cancer
Breast · subtype
PR+ breast cancer
Subtype of Breast cancer
Clinical / Scientific
PR expression usually marks a functional ER transcriptional axis. Isolated PR biology is less often an independent therapeutic node than ER. Mechanistic discussion should not treat PR+ as a fully separate disease when ER is co-expressed.
Core Biological Drivers
ER–PR coordinated transcription
PR is an ER-induced gene and modulates ER cistromes.
PI3K signalling
Shared with luminal breast cancer.
Key Pathways
Scientific explanation
ERα (ESR1) drives a large fraction of breast cancers via genomic and non-genomic signalling. ESR1 mutations and growth-factor crosstalk contribute to endocrine resistance.
Scientific explanation
phosphorylates PIP2 to PIP3, recruiting . supports growth, survival, glucose uptake and mTORC1 input. Pathway activation is common via PIK3CA mutation, PTEN loss or -tyrosine- signalling.
Scientific explanation
mTORC1 integrates growth-factor and nutrient signals to drive protein synthesis, lipid synthesis and suppression. It sits downstream of PI3K/AKT and amino-acid sensing.
Pathway Convergence
Target → pathway → downstream effect → biological consequence. Shared intersections are mechanistic maps, not protocols.
Growth-factor signalling
Ligand or mutation-driven RTK input feeds PI3K/AKT and mTORC1, supporting anabolic growth. This is a map of signalling, not a treatment protocol.
Metabolic Vulnerabilities
Aerobic supports ATP, biomass and acidification even when oxygen is available. Extent varies by tumour and remains a vulnerability hypothesis rather than a uniform target.
Tumor Microenvironment
Disordered vasculature creates , HIF-1α stabilization, induction and immune-suppressive adenosine/lactate milieus.
Metastasis Module
, protease-mediated invasion, , circulating tumour-cell survival and organ-specific colonization form the metastatic cascade. Pre-metastatic niches and vascular permeability influence tropism.
Resistance Biology
Loss of PR can accompany endocrine resistance without proving PR was the driver.
Cancer Stemness
Wnt, Notch, Hedgehog, ALDH and CD44-associated programmes can mark stem-like fractions with quiescence and therapy tolerance. These markers are not interchangeable across tumour types.
Mechanism-Based Adjunctive Strategies
Compounds appear only where a mechanistic overlap exists for this cancer. Evidence tiers are not equivalent. Nothing here is a treatment recommendation.
Target / Mechanism
Selective estrogen- modulator that antagonizes ERα-driven in breast epithelium while retaining partial activity in some other tissues.
Cancer relevance
Established SERM therapy for hormone--positive breast cancer according to labelled oncology practice. Tissue-specific / balance still applies.
Labelled endocrine therapy context. Convergence: Estrogen receptor, Apoptosis.
Target / Mechanism
Modest complex I inhibition raises AMP:ATP, activating and restraining hepatic and -linked anabolism. Direct antineoplastic efficacy is not established from that pharmacology alone.
Cancer relevance
activation and restraint provide a metabolic rationale in - and -linked tumours. Human data are mixed and do not establish metformin as cancer therapy.
Metabolic adjunctive research context. Convergence: AMPK, mTOR, Glycolysis.
Research Context
- Breast portraits. Perou CM, et al. Molecular portraits of human breast tumours. Nature. 2000;406(6797):747-752. https://doi.org/10.1038/35021093
- Tamoxifen. Jordan VC. Tamoxifen: a most unlikely pioneering medicine. Nat Rev Drug Discov. 2003;2(3):205-213. https://doi.org/10.1038/nrd1031
This oncology atlas is educational. Pathway maps, adjunctive strategies, and compound listings describe mechanistic relevance. They do not establish clinical efficacy, do not recommend treatment, and are not a substitute for oncology care. Evidence tiers are not equivalent.