Topic 2: Cancer

Question 1

What is meant by the term cancer?

Answer 1

used for diseases in which abnormal cells divide without control and have the ability to invade other tissues, and spread to other parts of the body through the blood and lymph systems

Question 2

How does cancer start? What goes wrong?

Answer 2

It occurs when a cell with DNA damage or mutations occurs but does not die when it should, causing it to continue to grow and divide creating a mass tissue called a tumour.

Question 3

What is a tumour?

Answer 3

a tumour is where new cells form when the body does not need them and may form a mass of tissue called a tumour.
- the uncontrolled growth can lead to the formation of a mass of a tissue.

Question 4

Do all cancers result in a tumor?

Answer 4

No, not all cancers result in a tumour.
Leukemia and lymphoma primarily affect the blood/bone marrow or lymphatic system and may not initially produce a solid tumour mass. They circulate in the bloodstream or accumulate in the lymph nodes

Question 5

What is a MALIGNANT tumour?

Answer 5

• cancerous tumours.
• cells in these tumours can invade nearby tissues and spread to other parts of the body.

Question 6

What is a BENIGN tumour?

Answer 6

• are NOT cancerous.
• the cells grow only locally and cannot spread by invasion or metastasis.

Question 7

Define metastasis

Answer 7

The spread of cancer from one part of the body to another

Question 8

3 differences expect to see in the appearance of cancerous cells compared to normal healthy cells

Answer 8

• Cancerous cells have a large or multiple nuclei
• Cancerous cells have an irregular shape
• Cancerous cells overlapped neighboring cells (overcrowding)

Question 9

Role of checkpoints in cancer

Answer 9

Checkpoints controls may not operate correctly and do not direct cells with DNA damage to stop progressing in the cell cycle.

Question 10

2 Types of Cancers

Answer 10

1. Carcinomas
2. Leukemia (decrease in WBC)

Question 11

Cancer cells reproduce every

Answer 11

2-6 weeks

Question 12

Role of TSG

Answer 12

turn off or decrease rate of cell division

Question 13

Role of POG

Answer 13

turn on or increase the rate of cell division

Question 14

Lifestyle risks that can lead to cancer

Answer 14

• smoking/alcohol
• diet high in fat
• lack of excercise

Question 15

Environmental risks that lead to Cancer

Answer 15

• Second Hand smoke
• Air pollution
• Radiation

Question 16

Where are the checkpoints located that control these 2 genes

Answer 16

The checkpoints:
1 - G1/S
2 - G2/M
3 - Metaphase

Question 17

If there is DNA damage or a mutation occurs during replication in the cell cycle what would normally happen to avoid the mutation being passed along?

Answer 17

If DNA damage is detected, the TSG puts a “brake” on the cell cycle. This “brake” is not removed unless the DNA damage is repaired.

In a cell with a mutated TSG gene, the braking system is defective, and the damaged cell goes on in the cell cycle and divides.

Question 18

Why don’t cancerous cells die by apoptosis?

Answer 18

In cancer cells, mutations to DNA convert proto-oncogenes to oncogenes. They continuously send “go” signals that tell the cell to stay in the cell cycle and keep on dividing.
Resulting in the replication of cancerous cells and ignoring any signals to undergo apoptosis.