1. Cancer Group of diseases Due to the uncontrolled division of cells
May cause tissue damage by:
blocking passageways, e.g. in the gut
destroying nerves
eroding bone

2. This benign mole on the skin has a regular appearance and coloration.
Malignant tumors are distinct from benign tumors because they spread and infiltrate the tissues around them.
This benign mole on the skin has a regular appearance and coloration.
A malignant melanoma (skin cancer) is assymetrical, with an irregular border, and an uneven color.

3. Cancer Is An Old Disease
Cancer is not a new disease; it has been detected in the remains of human bodies buried thousands of years ago.
Cancer is not restricted to the human species.
Most other animals suffer from cancer.
Evidence of it has even been found in the fossilized bones of dinosaurs.

4. White blood cells (leukocytes)
Types of Cancer
Carcinoma
The most common form of cancer. Arises from the cells forming skin, the glands (such as the prostate and mammary), the uterus, and the membranes of the respiratory and gastro-intestinal tracts. Carcinomas spread through lymph vessels.
Lymphatic cancer
Malignant tumor of the lymph tissue. Spreads to other parts of the body through lymph vessels.
Sarcoma
Malignant tumor arising in connective tissues, such as muscle, bone, cartilage, and the tissue covering muscles and fat. Spread through blood vessels.
Osteosarcoma of the foot
White blood cells (leukocytes)
Leukemia
Cancer of the tissues that form blood in the bone marrow. Characterized by uncontrolled production and accumulation of abnormal white blood cells.Spreads through blood and lymph vessels.

5. The Incidence of Cancer
The likelihood of developing cancer varies with age.
Although the incidence of cancer appears to be greater in humans in recent times, this may simply be because more people are living to an older age and are therefore more likely to develop cancer.
Percentage age related incidence of cancer
Percentage of people getting cancer

6. Susceptibility to Cancer
A person’s susceptibility to cancer is determined by:
Chemicals
Viruses
Familial (inherited) factors
Alcohol and diet
Ionizing radiation
Smoking

7. Cancer Cells The growth of a cancer begins when:
Normal cell
The growth of a cancer begins when:
The genes controlling cell growth and multiplication are transformed into oncogenes by agents called carcinogens.
Oncogenes increase the change of a normal cell developing into a tumor cell and increase the malignancy of tumor cells. The oncogenes are passed on to all offspring cells.
A small group of abnormal cells is established, and these divide more rapidly than the surrounding cells.
Cancer cells are generally undifferentiated. (i.e. they no longer perform the specialized function of their host tissue).
Years may pass before the cancer cells multiply enough to disrupt normal bodily function and cause symptoms.
Carcinogens
Cell seems normal but is predisposed to proliferate excessively
Cell begins to proliferate too much, but otherwise normal
Cell undergoes structural changes
Cell looks obviously abnormal and grows uncontrollably
Malignant cell

9. Features of a Cancer Cell
Metabolism may be disturbed and the cell ceases to function in its usual way.
The bloated, lumpy shape is readily distinguishable from a healthy cell, which has a flat, scaly appearance.
Cancer cells may have unusual numbers of chromosomes.
Cancer cells can go on dividing indefinitely if they have a continual supply of nutrients. They are said to be immortal.
Cancerous cells lose their attachments to neighboring cells.

10. Cancer Symptoms
The vast array of symptoms produced by the many different kinds of cancers depends on:
site of growth
tissue of origin
extent of the growth
Symptoms may include:
lumps (the growth of tumors)
bleeding
disruption of function of the organ affected. T K
Photo: CDC
Renal carcinoma
Note how much of the normal kidney tissue (K) has been replaced by gray and yellow tumor tissue (T).

11. Cancer Symptoms Severe recurrent headaches Persistent hoarseness
Difficulty swallowing
Coughing up bloody phlegm
Lump or change in breast shape, bleeding or discharge from nipple
Persistent abdominal pain
Change in shape/size of testes. Vaginal bleeding/spotting between periods or after menopause
Blood in urine, with no pain on urination. Change in bowel habits
Blemish or mole that enlarges, bleeds, or itches
Rapid weight loss without an apparent cause
Sore, scab, or ulcer that fails to heal within 3 weeks

12. Treating Cancer
The treatment of cancer is primarily surgical as removal of a tumor may often be a complete cure.
If the tumor cannot be surgically removed, or it is likely that metastases remain after surgery, the patient will be treated using:
radiotherapy and/or
chemotherapy
Chemotherapy
Radiotherapy

13. Common side effects of chemotherapy
Chemotherapy is the treatment of cancer by drugs that act selectively on the cancer cells.
Anticancer drugs act either by:
destroying tumor cells or
stopping them from multiplying
Unfortunately, the drugs used in these treatments may also detrimentally affect many normal tissues because they act on all rapidly dividing cells, not just tumor cells.
Hair loss
Oral ulcers
Reduced white blood cell production
Thinning of the intestinal lining
No gamete production

14. A linear accelerator used for radiotherapy
Ionizing radiation (normally a source of damage to DNA) is used to treat cancer tumors.
As radiation passes through diseased tissue, it destroys or slows the development of abnormal cells.
With the correct dosage of radiation, normal cells suffer very little and there is no long-term damage.
Side effects are usually short-lived and involve minor burning of the skin or some localized hair loss.
A linear accelerator used for radiotherapy
Radiation generator
Patient lies on adjustable table
Machine can be tilted to allow radiation of the tumor from various directions