On the origin of cancer metastasis.
Level 5 - mechanism / opinion, no new human data
Narrative review and theoretical hypothesis paper with no new human data.
PubMed 23237552 · doi:10.1615/critrevoncog.v18.i1-2.40
What was done
This review synthesized existing hypotheses regarding the biological origins and mechanisms of cancer metastasis. It evaluated models including epithelial-mesenchymal transition, mutation accumulation in stem cells, macrophage facilitation, and macrophage-derived origins via transformation or fusion hybridization.
What was found
The abstract reports no quantitative data or empirical measurements. It discusses theoretical mechanisms of the metastatic cascade and notes that metastatic cells share properties with normal macrophages, proposing that a macrophage-origin model explains the "seed and soil" hypothesis and the absence of metastasis in plant cancers.
Why it matters
Framing metastasis as a macrophage-related metabolic process provides an alternative conceptual model for understanding cancer dissemination and identifying potential therapeutic strategies.
Limits
This is a narrative review presenting theoretical models without primary empirical data, clinical trial outcomes, or quantitative metrics in the abstract. The proposed macrophage-origin mechanisms remain theoretical hypotheses requiring experimental validation.