Cancer

Cancer

Every 2 minutes someone is diagnosed with cancer in the UK/NZ

1 in 3 people will get cancer

Cancer causes ¼ of all deaths in the UK/NZ

420 people die from cancer every day - 1 every 4 minutes

7.5 million people are diagnosed with cancer each year worldwide.

Cancer is a term used for diseases in which there is uncontrolled growth of abnormal cells Cancer is not just one disease but many diseases. There are more than 100 different types of cancer.

Benign Malignant

What is cancer?

Not all tumours are cancerous; tumours can be benign or malignant.

Benign tumours aren't cancerous. They can often be removed, and, in most cases, they do not come back. Cells in benign tumours do not spread to other parts of the body.

Malignant tumours are cancerous. Cells in these tumours can invade nearby tissues and spread to other parts of the body. The spread of cancer from one part of the body to another is called metastasis.

Types of Cancers

Cancers can be grouped into broader categories. The main categories of cancer include:Carcinoma - cancer that begins in the skin or in tissues that line or cover internal organs

Sarcoma - cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

Benign Malignant

Leukaemia - cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and enter the blood.

Lymphoma and myeloma - cancers that begin in the cells of the immune system. Central nervous system cancers - cancers that begin in the tissues of the brain and spinal cord.

Sometimes cancer cells break away and travel to other parts of the body through the blood or lymph system.

They may form new colonies of abnormal cells in other parts of the body.

These new colonies of cells are called secondary growths or metastases.

Causes of cancer

Age Genes Smoking

Lifestyle

Alcohol Diet

Body weight

Sun exposure

Cancer is caused by changes –mutations- in a cell's DNA -- its genetic "blueprint".

Some of these changes may be inherited from our parents, while others may be caused by outside exposures, which are often referred to as environmental factors.

Causes of cancer

Environmental factors - Carcinogens

Environmental factors can include a wide range of exposures, such as lifestyle factors (nutrition, tobacco use, physical activity, etc.), naturally occurring exposures (ultraviolet light, radon, infectious agents, etc.), medical treatments (chemotherapy, radiation, and immune system-suppressing drugs used after organ transplants, etc.), workplace and household exposures, and pollution

Smoking – increases risk by 30%

Diet – too much processed food, fats, red meat, salt

Fibre - not enough fruit and veg

- increase risk by 20%

Over half of cancers could be avoided by healthy lifestyle

Most common cancers

Breast cancerMost common cancer in women

1/8 women

130 are diagnosed each day

340 men diagnosed each year

2/3 survive for over 20 years after diagnosis

mammogram

mastectomy

Most common between 15-44

2000 men diagnosed each year in UK

Survival rate is 95%

Testicular cancer

108 people diagnosed every day

Less than 10% survive

Most common cause of cancer death 1 in 5

95 people die a day

SMOKING CAUSES 90% OF CASES

Lung cancer

Paradoxically, radiation can………

Ionising Radiation released from radioactive material can cause alterations/ mutations in the DNA of a cell that can lead to altered growth

Cause cancer

X-rays, CT scans, Ultrasound, Gamma cameras all use aspects of radiation to provide pictures from inside the body

Diagnose cancer

It is important to be able to study internal organs, or tissues, without the need for surgery. In such cases, radioactive tracers can be injected into the body so such studies can take place. The path of these tracers can be detected using a gamma camera because of their radioactivity.

Nuclear Medicine Tracers

There is a time delay between injecting the tracer and the build-up of radiation in the organ.

Static studies are performed on the brain, bone or lungs scans

Static Imaging

Tracers Used in Nuclear Medicine

Such tracers are chosen so that: They will concentrate in the organ, or tissue,

which is to be examined. They will lose their radioactivity (short t). They emit gamma rays which will be detected

outside the body. Gamma rays are chosen since alpha and beta particles would be absorbed by tissues and not be detected outside the body.

Technitium-99m is most widely used because it has a half-life of 6 hours

Factors Which Affect the Choice of Tracer

A shorter half-life would not allow sufficient measurements or images to be obtained.

A longer half-life would increase the amount of radiation the body organs or tissues receive.

Why is a half-life of 6 hours important?

Ionising radiation released from radioactive material can be used externally or internally to target cancer cells with the aim of killing the cells

Treat Cancer

Radiation therapy uses ionising radiation to treat cancer i.e. to destroy cancerous cells.

There are two techniques in radiation therapy that are used to treat cancer using ionising radiation:

Radiotherapy Brachytherapy

Radiotherapy

The choice of treatment depends on a number of factors including:

The size of the tumour.

The position of the tumour.

Factors Which Affect the Choice of Treatment for Cancer

The cancerous tumour has to be located so that its size and position can be analysed. This information can be obtained from:

X-rays CT scans MRI scans Ultrasound images

Radiotherapy Treatment

Gamma rays are emitted from a cobalt-60 source – a radioactive form of cobalt.

The cobalt source is kept within a thick, heavy metal container.

This container has a slit in it to allow a narrow beam of gamma rays to emerge.

Radiotherapy Treatment

This involves placing implants in the form of seeds, wires or pellets directly into the tumour.

Such implants may be temporary or permanent depending on the implant and the tumour itself.

The benefit of such a method is that the tumour receives nearly all of the dose whilst healthy tissue hardly receives any.

Brachytherapy ( internal use of radiation)

Brachytherapy is used to treat the following cancers

Uterus Cervix Prostate Intraocular Skin Thyroid Bon

Brachytherapy ( internal use of radiation)

Other treatments include;

Drugs are used to destroy cancer cells

Can also harm healthy cells

Used to cure, control and ease symptoms

Chemotherapy

Used on external tumours, retina, cervix and early stage prostate cancer

Liquid nitrogen

Dissolves and forms a scab

Can affect fertility and cause scarring

Cryosurgery