development of cancer is multi-step process, requires accumulation of mutations in single cell, angiogenesis & metastasis >

causative agent causes gene mutations(bp sub/addition/deletion) in genes controlling checkpoint of cell cycle >

GOFM in 1 copy of POG results in excessive amounts of protein products leads to uncontrolled cell division OR

LOFM in both copies of TSG results in non-functional protein products which disrupts ability of cell to arrest cell cycle leads to uncontrolled cell division >

mutations in same somatic cell results in rate of cell division>rate of cell death, leading to uncontrolled cell division & tumour formation >

angiogenesis, growth of new blood vessels occurs within tumour to transport O₂, nutrients to support growth of tumour >

cells of tumour invade surrounding tissue & metastasise to other sites, tumour considered malignant; cancer has developed

Review: H2 Biology 21 - Cancer