OnCo
pathwaysPathway

The metastatic cascade

How cancer spreads: cells leave the tumour, squeeze into blood or lymph vessels, survive the journey, exit into a new organ, often sleep there for years, and finally grow. Metastasis causes about 90% of cancer deaths.

Invasion (EMT, matrix proteases), intravasation, survival in circulation as CTCs or clusters (platelet cloaking, anoikis resistance), arrest and extravasation, then colonisation, which is the rate-limiting step: most disseminated tumour cells (DTCs) die or stay dormant. Organ tropism follows Paget's seed-and-soil: pre-metastatic niches are prepared by tumour-derived exosomes and myeloid cells. Clinically, ctDNA and MRD assays detect the cascade before imaging; adjuvant therapy targets it blind; no drug specifically blocks colonisation yet.

In one picture

A seed leaving a plant: it must detach, ride the wind, land somewhere with the right soil, survive the winter, and only then sprout. Almost every seed fails; the few that grow are the metastases.

Diagram

top
Primary tumourInvasion (EMT, MMPs)IntravasationCTCs in circulationExtravasationDTC dormancyColonisation / macrometas…Pre-metastatic niche (exo…NK / T-cell clearanceactivatesinhibitsdruggable target (click)hit by selected productescape route

How drugs attack it

4top
  • Adjuvant systemic therapy and ctDNA-guided escalation aim at DTCs before colonisation
  • Anti-EMT and anti-MMP drugs failed historically; TGF-β blockade is being retried in combinations
  • Dormancy-maintaining strategies (see tumour dormancy) are the newest idea
  • Metastasis-directed SBRT for oligometastatic disease

Notes

top
  • Leading programmes: Massagué lab (MSK) on metastasis-initiating cells and dormancy; Swanton/TRACERx (Crick) on evolution and dissemination timing; Egeblad (CSHL) on neutrophils and dormancy awakening; DKFZ Metastasis Research.
  • Massagué & Ganesh, Cancer Cell 2023 review: https://doi.org/10.1016/j.ccell.2023.02.020

Connected

28top

Pages like this

not linked directly; found by shared links