S

CANCERTPJ4M

OBJECTIVE

Define and discuss cancer

Cancer

Definition – abnormal growth of cells that can invade surrounding tissue and spread to other parts of the body

Cancer cells can originate in any body tissue

Your cells

The Cell Cycle

The series of events a cell undergoes from the time it is formed until it grows and reproduces new cells:

1. Interphase – resting and growth phase where the cell spends most of its life

2. Mitosis – division phase where the nucleus divides (Prophase, Metaphase, Anaphase, Telophase) *PMAT

3. Cytokinesis – cell division where the cell divides in half

Cell Cycle

Normal Cells (NC) Cancerous Cells (CC)

Once NC grow and mature, cell division stops because able to fully function

CC keep on dividing, never mature, thus do not stop growing and not fully functioning

DNA mutations disrupt the cell cycle.

Mutations may be caused by:

1. radiation

2. smoking

3. Pollutants

4. chemicals

5. viruses

Cancer Cells

Cancer cells experience uncontrolled and disorganized cell growth

Cancer cells enter mitosis repeatedly and never grow to maturity

Cancer cells eventually form a growth called tumor

Tumors invades and destroys neighbouring healthy cells

Two Main Types of Cancer

Carcinoma Skin Lining of hollow organs

and passageways

Sarcoma Bone Muscle Lymph cartilage

OBJECTIVE

List two types of tumours and explain how they are different

Explain metastasis

Tumour – Growth of Abnormal Cells

Benign tumour Grows slowly Localized area

Malignant tumour grows slow or fast depending on type of cancer Invades other tissues and/or travels to other parts of body Causes death if not treated and controlled

THE IMPORTANT DIFFERENCE B/W BENIGN AND MALIGNANT TUMOURS IS THAT ONE INVADES AND SPREADS (MALIGNANT)

Benign Tumors (Not Cancerous)

Malignant Tumors (Cancerous)

As they grow benign tumors simply push the surrounding normal tissues and organs out of their way.

Malignant tumors eat into and destroy the normal tissue around them as they increase in size.

Sometimes pressure from a benign tumor may damage surrounding structures but the benign tumor never actually invades into those structures.

Malignant tumors invade and damage structures.

Benign tumors can grow quite large without causing any problems.

Malignant tumor damages the tissue around it from the time it first begins to grow.

Benign tumors do not spread. They may grow to a large size but they do not go to other parts of the body.

Malignant tumors have the ability to spread by sending off seedlings of tumor which can pass through the blood or lymphatic system to other parts of the body. These seedlings then settle in other organs and form what are called secondary tumors or metastases.

Cancer – Most Common Sites

Skin

Lungs

Colon

Rectum

Breast

Prostate

Uterus

METASTASIS

OBJECTIVE

List the seven warning signs of cancer

Caution – Seven Early Warning Signs of Cancer

Change in bowel or bladder habits

A sore that does not heal

Unusual bleeding or discharge

Thickening or lump in breast or elsewhere

Indigestion or difficulty in swallowing

Obvious changes in wart or mole

Nagging cough or hoarseness

OBJECTIVE

Describe the three most common types of treatment for cancer

Standard Cancer Treatment

Surgery

Radiation therapy

Chemotherapy Oral Intramuscular Intravenous

Chemotherapy

*Treatment of cancer with an antineoplastic drug or in combination with such drugs*****Antineoplastic drugs (control or kill neoplastic cells – part of tumor)

*The most common chemotherapy agents act by killing cells that divide rapidly

*Chemotherapy also harms cells that divide rapidly under normal circumstances: cells in the bone marrow, digestive tract, and hair follicles.

Side-effects of chemotherapy

*Decreased production of blood cells (because it affects the bone marrow)

*Inflammation of the lining of the digestive tract

*Hair loss (because it affects the hair follicles)

Radiation Therapy

Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells

The radiation may be delivered by a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, also called brachytherapy).

Systemic radiation therapy uses radioactive substances, such as radioactive iodine, that travel in the blood to kill cancer cells

How does Radiation Therapy kill cancerous cells?

Radiation therapy kills cancer cells by damaging their DNA

Cancer cells whose DNA is damaged beyond repair stop dividing or die

However radiation therapy can also damage normal cells, leading to side effects

Side effects of Radiation Therapy

Skin irritations

Damage to salivary glands

Fatigue

Nausea

Vomiting Damage to the bowels, causing diarrhea and bleeding. Memory loss. Infertility (inability to have a child).

REVIEW

1. Define cancer.2. Discuss cancer in relation to normal cells and the cell

cycle.3. List two types of tumours. What is the main

difference?4. What acronym is used for the 7 early warning signs

of cancer? List the 7 signs5. Describe each of the 3 most common cancer

treatments – add to existing answer.6. Add to your answer for metastasis