1. CELL DIVISION GOING WRONG: Cancer
2.7
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.
cancer

2. CELL DIVISION GOING WRONG: Cancer
2.7
TUMOURS
Uncontrolled growth may create a rapidly growing mass of cells that form a lump, or tumour.
Tumours may be benign or malignant. Cells in a malignant tumour are considered cancerous.
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.
tumour benign tumour malignant metastasis

3. METASTASIS
Step 1. The primary tumour develops as a group of cells that are growing out of control.
Step 2. The tumour gets bigger and stimulates blood vessels to supply it from the surrounding tissues.
Step 3. Tumour cells squeeze into blood and lymph vessels and move to other parts of the body. This is called metastasis.
Step 4. When the tumour cells reach other areas of the body, like the liver and lungs, they begin to grow and form secondary tumours. If they are not treated quickly enough, the damage that these secondary tumours cause can be fatal.

4. CELL DIVISION GOING WRONG: Cancer
2.7
MUTATIONS
When cells divide, their DNA is almost always duplicated error-free. The genetic information in their daughter cells is identical to the parent cell.
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.
mutations carcinogens

5. CELL DIVISION GOING WRONG: Cancer
2.7
CARCINOGENS
Some mutations are caused by carcinogens. Carcinogens are environmental factors that cause cancer. Examples include tobacco smoke, radiation (UVA and UVB) , some viruses, certain chemicals, and many organic solvents.
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.
Some cancers are at least partly hereditary. These include some breast cancers and colon cancers.
mutations carcinogens

6. CELL DIVISION GOING WRONG: Cancer
2.7
CANCER SCREENING
Factors affecting a person’s risk of getting cancer include
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
While screening does not prevent cancer, it does increase the likelihood of early detection and successful treatment.
pap test
Super foods such as these help your
body protect itself from cancers

7. CELL DIVISION GOING WRONG: Cancer
2.7
CANCER DIAGNOSIS AND TREATMENT
The earlier a cancer is diagnosed, the better the chances of 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.
The purpose of cancer treatment is to slow down the growth of tumours or destroy as many cancer cells as possible. Currently, there are three methods of conventional treatment:
surgery
chemotherapy
radiation therapy
One new technique to fight cancer is biophotonics, which uses beams of light to detect and treat the cancer cells.
Vocabulary
Pap test