Transcript Disorders of Cell Growth

Disorders of Cell Growth
Cancer
Oncology
• Study of cancer
• 25% of Americans develop cancer at some
point in life
Nature of cancer cells
• Normal cells that have a permanent
CHANGE in them
• Cancer cells perpetuate themselves
• Lose normal growth regulation
Characteristics of cancer cells
Cancer Cells
• Lack of contact inhibition. Cancer cells
lack this and continue growing even if they
have contact with neighboring cells
• Tumor – Growth e.g. adenoma
• Neoplasia – “new” growth
Cancer cells
• Invade and infiltrate normal cells
• Lack of differentiation
– Abnormal size & shape
– Abnormal nucleus
Normal cells have differentiation
Cancer cells
• Loss of normal functions
• Divert more blood vessels for themselves
for more nutrients
Malignancy
• Detachment and spreading
• Metastasis – cancer cells can detach and
spread. Typically they spread via the
bloodstream or via lymph vessels
Cancer cells
• Benign = “innocent” These tumors do not
metastasize
• Malignant = Cancer. These do
metastasize
Causes of Cancer
• Predisposing factors increase the
likelihood of developing cancer
• Increase in cell number
• Disordered cell proliferation
• Chronic irritation resulting in changed cells
• Stressors suppressing the immune system
• Hereditary predisposition
Initiation
• DNA mutation
• Not repaired
• Changing of a normal cell to an abnormal
cell
Promotion
• Providing an environment for
uncontrollable growth
• Encourages growth
Carcinogens
• Agents that initiate or promote abnormal
cells and their growth
• 85% of all carcinogens are environmental
Progression
• Abnormal cells become malignant
Immune System
• Our immune system is constantly spotting
abnormal cells
• Our immune system can recognize more
than 10 million different cancer antigens
Treatments
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Surgery
Radiation
Chemotherapy
Immunotherapy
Danger Signals of Cancer
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Bleeding, discharge
Lumps, thickening
Non-healing sores
Bowel or urinary changes
Hoarseness or cough
Mole or wart change
Difficulty swallowing/ indigestion
Breast lump
Avoidance
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75% cancer deaths are related to lifestyle
Avoid direct sunlight
Low fat diet
Quit smoking
Increase roughage in diet
Fresh fruits & vegetables
Early detection
Types of Cancer
• Carcinoma – Cancer of the epithelial
tissue
• Sarcoma – Cancer of connective tissue
• Leukemia – Cancer of blood
• Lymphoma – Cancer of Lymph tissue