ONCOPATHOLOGY
,Hallmarks of Cancer
• Self-sufficiency in growth signals
• Insensitivity to growth inhibitory signals
• Evasion of cell death
• Limitless replicative potential
• • Development of sustained angiogenesis
• • Ability to invade and metastasize
• Reprogramming of energy metabolism
• Evasion of the immune system
• Genomic instability
• Tumour-promoting inflammation
,Development of Sustained Angiogenesis
• Tumours cannot enlarge beyond 1 to 2 mm in diameter unless they
are vascularized for delivery of oxygen and nutrients and removal o
waste products
• Maximal distance across which oxygen, nutrients, and waste can diffuse fr
blood vessels
• Cancer cells (and large benign tumours) can stimulate
neoangiogenesis, during which new vessels sprout from previously
existing capillaries, or, in some cases, vasculogenesis, in which
endothelial cells are recruited from the bone marrow
• Tumour vasculature is abnormal, however. The vessels are leaky an
dilated, with a haphazard pattern of connection
, • Neovascularization has a dual effect on tumour growth:
• Perfusion supplies needed nutrients and oxygen
• Newly formed endothelial cells stimulate the growth of adjacent tumour c
by secreting growth factors, such as insulin-like growth factors, PDGF, and
granulocyte-macrophage colony-stimulating factor
• Angiogenesis is required not only for continued tumour growth bu
also for access to the vasculature and hence for metastasis, thus a
necessary biologic correlate of neoplasia, both benign and maligna
,Hallmarks of Cancer
• Self-sufficiency in growth signals
• Insensitivity to growth inhibitory signals
• Evasion of cell death
• Limitless replicative potential
• • Development of sustained angiogenesis
• • Ability to invade and metastasize
• Reprogramming of energy metabolism
• Evasion of the immune system
• Genomic instability
• Tumour-promoting inflammation
,Development of Sustained Angiogenesis
• Tumours cannot enlarge beyond 1 to 2 mm in diameter unless they
are vascularized for delivery of oxygen and nutrients and removal o
waste products
• Maximal distance across which oxygen, nutrients, and waste can diffuse fr
blood vessels
• Cancer cells (and large benign tumours) can stimulate
neoangiogenesis, during which new vessels sprout from previously
existing capillaries, or, in some cases, vasculogenesis, in which
endothelial cells are recruited from the bone marrow
• Tumour vasculature is abnormal, however. The vessels are leaky an
dilated, with a haphazard pattern of connection
, • Neovascularization has a dual effect on tumour growth:
• Perfusion supplies needed nutrients and oxygen
• Newly formed endothelial cells stimulate the growth of adjacent tumour c
by secreting growth factors, such as insulin-like growth factors, PDGF, and
granulocyte-macrophage colony-stimulating factor
• Angiogenesis is required not only for continued tumour growth bu
also for access to the vasculature and hence for metastasis, thus a
necessary biologic correlate of neoplasia, both benign and maligna
