CANCER DOCUMENTARY, TUTORIALS, & GAMES: http://www.cancerquest.org/index.cfm?page=3102#

1. 1 in 3 people will contract cancer, and of those, 1 in 4 will die from the disease.

2. Within 5 years, cancer will surpass heart disease as the leading cause of death.

3. Since 1950, the overall cancer incidence has increased by 44 percent.1. Breast cancer and male colon cancer increased by

about 60 %2. Testis, prostate and kidney cancer increased by

100 %3. Other cancers, such as malignant skin cancer and

some lymphomas, also increased by over 100 %.

1. The rates of certain types of cancer among some industrial workers are up to 10 times higher than in the general population. 1. Children of workers handling chemical carcinogens have sharply

increase cancer rates. 2. For example, the risks of childhood leukemia are increased two-

to-five-fold if, during their mother's pregnancies, their fathers worked with spray paints, dyes or pigments.

2. Some 75 percent of all cancers develop in those over 55, but notable exceptions include childhood leukemia, testicular and brain cancers - which mainly strike young people and have been increasing at an alarming rate, particularly among peak age groups 1. For example, there has been an approximate 300 percent

increase in testicular cancer among those aged 25-34 since the 1950s.

Fl. Describe cancer with respect to (p. 518): abnormal nuclei, disorganized and uncontrolled growth (anaplasia), lack of contact inhibition, vascularization, and metastasis.

F2. List the seven danger signals that may indicate the presence of Cancer

F3. Differentiate between a proto-oncogene & an oncogene (p. 520)

F4. Use examples to outline the roles of initiators and promoters in carcinogenesis. F5. Demonstrate a knowledge of how a virus can bring about cancer.

_____ Anaplasia_____ Benign_____ Carcinogen_____ Carcinogenesis_____ Carcinoma_____ Contact inhibition _____ Initiator_____ Malignant_____ Metastasis

_____ Mutagen_____ Neoplasia_____ Oncogene_____ Promotor_____ Protooncogene_____ Retrovirus_____ Tadpole nucleus_____ Tumour_____ Vascularization

Why?

It is not (usually) caused by a pathogenpathogen and it does not have one set of symptomssymptoms.

1. Normal cells grow at a slow and steadyslow and steady pace.

2. When a cell has an quick and uncontrolled rate of cell uncontrolled rate of cell divisiondivision (once every 3 hours) it has no time to differentiatedifferentiate in to cells with specific jobs.

3. These cells are uselessuseless and have no functionfunction, but they still need nutrients and oxygennutrients and oxygen. They stealsteal these from the rest of the body.

4. If this remains unchecked, it will result in the death death of the organism.

5.5. 15 to 2015 to 20% of all deaths in North America are due to cancer.

A normal cell becomes a cancer cell due to a genetic change or MUTATIONMUTATION.

This is caused by either:

1. MutagenMutagen: any substance or thing that induces mutations in cells.

2. CarcinogensCarcinogens: any substance or thing that produces a mutation that results in a cell becoming cancerous.

Not all carcinogens will cause cancers in all people all of the time. Different people must have variable ‘susceptibility’variable ‘susceptibility’ to cancer.

PROTO-ONCOGENESPROTO-ONCOGENES are normal genesgenes in the body involved in controlling cell divisioncell division.

When they are functioning normally, they are genes that either tell a cell to divide divide OR tell a cell to stop dividingstop dividing.

However, a mutationmutation in one of these genes can change the proto-oncogene in to an oncogeneoncogene (cancer gene).

Things that can mutate proto-oncogenes to oncogenes are called INITIATORSINITIATORS.

In some cases a change/mutation in a single base pairsingle base pair can cause this to happen.

Initiators are mutagens and carcinogensmutagens and carcinogens. They can be chemicals, radiation, poor diet, etc.

Initiators are classified in four ways:1.1. CarcinogensCarcinogens: radiation or chemicals in the environment can

cause mutation (i.e.: smoking)

2.2. Chromosome mutationChromosome mutation can happen normally during cell division (i.e.: deletion, addition, inversion)

3.3. TransfectionTransfection: exchange of DNA from one cell to another

4.4. ViralViral: a retrovirus can either:1. Introduce an oncogeneoncogene in to the DNA. 2. Introduce a piece of genetic material into a proto-oncogene,

thus mutating itmutating it.

* Cooperation: Sometimes two or more oncogenes are required to work together (cooperatively) in order to become cancerous.

An oncogene may not immediately turn into cancer.

There may need to be another external agent called a PROMOTERPROMOTER..

It is the promoter that “turns turns onon” the oncogene, resulting in cancer.

Once you have Cancer, there are 4 Stages in its Development:

Step 1) NeoplasiaNeoplasia - non differentiated cell divisioncell division

Step 2) AnaplasiaAnaplasia - disorganised growth (start of tumourstart of tumour)

Step 3) VascularizationVascularization - growth factors are released by the tumour to promote nearby vesselspromote nearby vessels to branch out so blood blood vessels will grow into the tumourvessels will grow into the tumour.

This provides the fast growing cells of the tumour with more nutrients and O2.nutrients and O2.

http://www.pbs.org/wgbh/nova/programs/ht/qt/2805_03.html

Step 4) Metastasis Metastasis -- cells break off from tumor, spreadspread & cause new tumors.

Metastasis is the major mode of spreading cancer and usually moves through the Circulatory or LymphaticCirculatory or Lymphatic system.

Why? These are both thin walledthin walled vessels that reach everywhere ineverywhere in the body. Cancer cells can easily penetrate the thin walls & then be transported in the vessels.

http://www.pbs.org/wgbh/nova/programs/ht/qt/2805_06.html

Neoplasia Mild Anaplasia

Moderate Anaplasia

Severe Anaplasia

Vascularization

Normal cells

http://ca.youtube.com/watch?v=dvDUXKegwZw

http://ca.youtube.com/watch?v=PoRx24eDW6U&feature=related

1.1. Grow and divide Grow and divide rapidlyrapidly..

2.2. Have Have Mutated DNAMutated DNA (in cell division genes). It is believed that cancer is started by multiple DNA mutations, either from toxic triggers, introductions from a virus, or natural random errors.

3.3. Enlarged in sizeEnlarged in size: : the nucleus is enlarged and often has an irregular shape.

4.4. Lack Lack differentiationdifferentiation:: like stem cells, they have no function.

5. They lack lack CONTACT INHIBITIONCONTACT INHIBITION. Cancer cells do not stop growing when they touch other cells.

6.6. Form Form tumourstumours: : masses of cells on top of each other.

7. 7. No cell-to-cell junctionsNo cell-to-cell junctions: : whereas normal cells attach together firmly to form tissues, cancer cells do not stick to each other. They are easily dislodged from each other.

8. Cancer cells have the have the ability to metastasizeability to metastasize. They move to other parts of the body and grow into tumours wherever they go.

5. Cancer cells continue to dividecontinue to divide even when they are separated or isolated

6.6. VascularizationVascularization: : cancerous tumours can stimulate the circulatory system to grow new blood vessels in to the tumour. In this way the cancer cells steal nutrients and oxygen from the rest of they body.

AngiogenesisAngiogenesis: the growth of new blood vesselsgrowth of new blood vessels in to a tumour.

There are two types of tumours:

1.1. BenignBenign tumour: Non-cancerousDoes not spread Generally harmless (ie: moles, warts, etc…)

2. MalignantMalignant (cancerous) tumour: These cells that lack ‘contact inhibition’ and form

into lumps and tumoursThey can metastasize

1. A change in bowel or bladderbowel or bladder habits

2. A sore that does not healdoes not heal

3. Unusual bleedingUnusual bleeding or discharges

4. A thickening lumplump in the breast or elsewhere on the body

5. Indigestion or difficulty in swallowingdifficulty in swallowing

6. Obvious changesObvious changes in a wart or mole

7. A nagging coughnagging cough or hoarseness

1. There appears to be a genetic predispositiongenetic predisposition to getting cancer.

2. You are more likelymore likely to contact the disease if close family members have also had it.

3. For example, with breast cancer, 2 genes have been identified so far (in 1996) that if a particular mutation is present in either gene, a woman is 8080% more likely to develop breast cancer.

Genetic Mapping Determine Cancer Risk: http://www.youtube.com/watch?v=Iwy-Tfetr1Q&feature=fvw

•SmokingSmoking: Tobacco use is the cause of an estimated 30% of fatal cancers in Canada and is the overwhelming cause of lung cancer;

•Poor dietPoor diet: At least 20% of cancer deaths are linked to a poor diet - including consumption of alcohol.

•Eat fruits and veggies (8 servings). Eat lots of fibre to flush out the toxins.

•Limit red meat, processed meat, saturated fats.

•Sunlight: Skin cancer is the most commonly occurring cancer. One of the main causes of skin cancer is exposure to the sun's ultraviolet (UV) rays.

•Others:

•ChemicalsChemicals in our workplace, on our food, in our cleaning products, plastics, cooking tools (teflon), beauty products and environment etc…

•RadiationRadiation in our workplace and environment.

•Viral infectionsViral infections (HPV), and reproductive patterns (ie: breast feeding before age 30).

Here are some interesting breast cancer statistics:• About 1.2 million cases of breast cancer will be diagnosed this year worldwide, according to the World Health Organization.• About 75% of breast cancers are found in women over age 50.• The chance of having breast cancer for a woman in her fifties is about 1 in 50.• The chance of having breast cancer for a woman in her nineties is about 1 in 9.• About 80% of women diagnosed with breast cancer have no family history of breast cancer.• Men also get breast cancer, however, men account for less than one percent of all breast cancer cases.

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