Download Cancer Basics

Cancer Basics
EQ: What does cancer have to do with the
cell cycle?
What is cancer?
• Cancer is a disease of the cell cycle.
• Cells divide when they are not supposed to.
• Develop into tumors and eventually spread to
other parts of the body.
Causes
• Cell with damaged DNA divides repeatedly.
• Normal cell cycle checkpoints do not
function.
• Caused by:
– Genetics
– Drug or chemical exposure (carcinogens)
– Accidental mutations
Cancer Progression
• DNA of cell is damaged
– DNA is not repaired. Cell does not die.
• Cell with damaged DNA multiplies.
– Immune system does not kill faulty cells.
• Tumor forms
• Blood vessels carry cells to other parts of
body (metastasis)
Terms to Know
• Benign tumor – a tumor that is not cancerous
– Will not spread to other parts of body
– May be removed if it presses on other organs
• Malignant tumor – mass of cancer cells
• Carcinoma in situ – early cancer that has not
yet formed a tumor
– Easiest type of cancer to treat
• Metastasis – spread of cancer to other parts
of the body
– Most difficult cancer to treat
Types of Cancer
• Any part of the body can develop cancer
– Most common cancers are in organs whose cells
divide rapidly
– Skin cancer, leukemia, lung cancer
• Named for the part of the body in which it
began
– A liver tumor that is the result of breast cancer is
still breast cancer
– Each cancer spreads to other organs in a
predictable sequence
Treatment
• Surgery – physically cutting out a tumor
– Very effective before cancer metastasizes
– Few side effects
– If only one cell is left behind, cancer will recur
Treatment
• Radiation – uses waves to damage the DNA
of the cancer cells so they cannot divide
– Used to treat cancer that has metastasized
– Also damages DNA of healthy cells
– Doctors will attempt to target specific cancer sites
Treatment
• Chemotherapy – used drugs to inhibit the
mitotic spindle so cancer cells can’t divide
– Also stops mitosis in healthy cells
– Side effects: nausea, anemia, hair loss, fatigue
– Used when cancer has metastasized
Prognosis
• Depends on the type of cancer, stage, and
the TNM status
• All cancers are easier to treat when caught
early
• Stage IV is the most severe. Treatment at
this stage usually only extends the patient’s
life a few months or years.