19 Cancer

Question 1

Characteristics of Cancer Cells

Answer 1

1. Lack differentiation and do not contribute to normal body functioning
2. Have abnormal, enlarged nuclei and may have abnormal number of chromosomes
3. Unlimited ability to divide
4. Form cancerous tumors (benign do not invade)
5. Divide without need for hormonal growth
6. Become abnormal gradually through multistage process
7. Undergo angiogenesis (form new blood vessels) and metastasis (distant spread via blood or lymph)

Question 2

Angiogenesis

Answer 2

Formation of new blood vessels

Question 3

Metastasis

Answer 3

Distant spread via blood or lymph

Question 4

3 Phases of Cancer Development

Answer 4

1. Initiation: single cell undergoes mutation
2. Promotion: tumor develops and cell within the tumor mutates
3. Progression: cell mutates in a way that allows to invade surrounding tissues

Question 5

Genetic Basis for Cancer

Answer 5

• Tumor-Suppressor Genes: their products inhibit the cell cycle and promote apoptosis
• Proto-Oncogenes: their products promote cell cycle and prevent apoptosis

THERE IS NORMALLY A BALANCE BETWEEN THESE TWO TYPES. MUTATIONS IN EITHER OR BOTH PREDISPOSES TO CANCER.

Question 6

Types of Cancer

Answer 6

• Carcinoma: epithelial tissue, e.g. skin
• Adenocarcinoma: glandular epithelial e.g. breast, prostate, cervix, stomach
• Sarcoma: muscle and connective tissue
• Leukemia: blood
• Lymphoma: lymphatic tissue

Question 7

Causes of Cancer

(Genetic)

Answer 7

• BRCA1 and BRCA2 - tumor suppressor genes that are associated with breast cancer
• RB - tumor suppressor gene that is associated with an eye tumor (retinoblastoma)
• RET - protooncogene that is associated with thyroid cancer

Question 8

Causes of Cancer

(Environmental Carcinogens)

Answer 8

• Radiation: UV Light
• Organic chemicals: tobacco
• Viruses: Hepa B and C can cause liver cancer, Epstein-Barr can cause Burkitt Lymphoma, HPV can cause cervical cancer

Question 9

Standard Treatment of Cancer

Answer 9

1. Surgery: removal
2. Radiation Therapy: localized therapy causes tumor cells chromosomal breakage and disrupts cancer cycle
3. Chemotherapy: Drugs that treat the whole body that kills tumor cells by damaging their DNA or interfering with DNA synthesis
4. Bone Marrow Transplant: first, completely destroy patient’s bone marrow, then transplant new bone marrow from a donor

Question 10

New Cancer Therapy

Answer 10

1. Immunotherapy: inject immune cells that are genetically engineered
2. Passive immunotherpy: antibodies that are linked to radioactive isotopes or chemotherapeutic drugs injected into the body
3. p53 gene therapy: retrovirus in clinical trials that is injected into the body where it will infect and kill only tumor cells
4. Angiogeneis inhibition: angiostatin and endostatin drugs in clinical trials that appear to inhibit angiogenesis