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12/8/2016
CELL DIVISION GONE WRONG: 2.7
CANCER
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When cells grow and divide out of
control, they cause a group of
diseases called cancer.
The result is a change in the DNA
that
controls the cell cycle. This
change
prevents the cell from staying in
interphase for the normal period
of time.
When the normal checkpoints fail,
the cell and its daughter cells will
divide uncontrollably.
CELL DIVISION GONE WRONG:
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CANCER
TUMOURS
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Uncontrolled growth may create a rapidly growing mass of
cells that form a lump, or tumour.
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Tumours may be benign or malignant. Cells in a malignant
tumour are considered cancerous.
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Cancer cells may break away from the original tumour and
move to a different part of the body. If they settle and grow in
this new location, a new tumour will form. This process of
breaking away and creating secondary tumours is called
metastasis.
Lung Cancer
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12/8/2016
CELL DIVISION GONE WRONG:
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CANCER
MUTATIONS
CELL DIVISION GONE WRONG:
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CANCER
CARCINOGENS
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When cells divide, their DNA is almost always duplicated
error-free. The genetic information in their daughter cells
is identical to the parent cell.
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Some mutations are caused by carcinogens. Carcinogens are
environmental factors that cause cancer. Examples include tobacco
smoke, radiation, some viruses, certain chemicals, and many organic
solvents.
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Sometimes random changes occur in the cell’s DNA. These
changes are called mutations. Changes may result in the
death of the cell or allow it to survive and continue to grow
and divide. If the cell cycle is abnormal, the cells may be
cancerous.
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Lung cancer is the most common type of cancer in Canadians over 40
years of age. Health Canada reports that 9 out of 10 lung cancer cases
are caused by smoking. The figure below identifies other parts of the
body that are affected by the carcinogens in tobacco smoke.
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Some cancers are at least partly hereditary. These include some breast
cancers and colon cancers.
CELL DIVISION GONE WRONG:
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CELL DIVISION GONE WRONG:
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CANCER SCREENING
Factors affecting a person’s risk of
getting cancer include:
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– personal and family medical
history
– exposure to carcinogens in
the environment
– lifestyle choices, such as
eating more
“super foods”
Cancer screening means checking for cancer even when no
symptoms are present. Screening can be performed:
– at home, as part of a routine self-examination
– by a doctor, such as a Pap test or blood test
– as genetic testing, when there is a family
history of cancer
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While screening does not prevent cancer, it does increase the
likelihood of early detection and successful treatment.
CELL DIVISION GONE WRONG:
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CANCER DIAGNOSIS AND TREATMENT
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CELL DIVISION GONE WRONG:
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CANCER DIAGNOSIS AND TREATMENT
Vocabulary
The earlier a cancer is diagnosed, the better the chances of
Pap test
successful treatment. Some diagnostic imaging techniques
include endoscopy, X-ray, ultrasound, CT scanning, and
MRI.
Once an abnormality has been identified, a sample of the
cells is removed and examined under a microscope. This is
called a biopsy. This is the only way to positively confirm a
diagnosis of cancer.
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Vocabulary
The purpose of cancer treatment is to slow down the growth
of
Pap test there
tumours or destroy as many cancer cells as possible. Currently,
are three methods of conventional treatment:
– surgery
– chemotherapy
– radiation therapy
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One new technique to fight cancer is
biophotonics, which uses beams of light
to detect and treat the cancer cells.
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