F00574 003 f005

First mutation

DDEOCttCrc

First mutation Normal

/_ epittielium — — Basal lamina

-    Blood vessel

-    Connective tissue

-    Lymphatic

Initial proliferation

Smali adenoma

Further mutation

Inherited oracquired gain of oncogene Loss of tumour suppressor gene

Further mutation; subset selected for rapid growth

Further mutation ->invasion or metastasis

Ł

fF

Lymphatic spread -

Blood spread -

Carcinoma

Ectopic growth factor production and autostimulation

Local invasion through basal lamina

t Angiogenesis to support tumour growth

Failed apoptosis {e.g. p53 mutation)

/

Breakdown of connective tissue via tumour production of e.g. collagenase

tissue metalloproteinases Loss of celi adhesion molecules e.g. E-cadherin

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