Pathways of tumour spread
- Lymphatic – spread to LNs (+/- may be destroyed by immune cells) - eg carcinomas
- Haematogenous – usually spread via veins first – veins easier to penetrate → liver & lungs, vertebra - eg sarcomas
- Also thyroid cancer, prostate, renal cell CA, HCC
- Cavity – abdominal (trans-coelomic), pleural- eg ovarian
- Direct invasion
- Involves adhesion, invasion, expression of motility factors, & passage through extracellular matrix (+/- via production of collagenases)
- Artificial transplantation – eg implantation via surgical instruments