Cancer Treatment

What is Cancer?

Cancers are a result of uncontrolled cell division. The type of nuclear division involved in mitosis. The problem is caused by mutations or abnormal activation of the genes which control cell division. When the genes are abnormal they are called oncogenes extracted from onkos meaning tumour. A single faulty cell may divide to form a clone of identical cells. Eventually an irregular mass of relatively undifferentiated cells called a tumour is formed. Tumour cells can break away and spread to other parts of the body; particularly in the bloodstream or lymphatic system, causing secondary tumours or metastases. This process is called metastasis. Tumours that spread and eventually cause ill health and death are described as malignant. The majority of tumours, such as common warts, do not spread and are described as benign.

Types of Cancer

More than 200 types of cancer have been discovered. Some of them are listd below:

Cervical cancer, breast cancer, colon cancer, colorectal cancer, lung cancer, heart cancer, eye cancer, skin cancer, prostate cancer, stomach cancer.

Breast cancer is the most common cancer in women and lung cancer in men.

Causes of Cancer

Changes in genes are called mutations and any factor bringing about a mutation is called mutagen. An agent which causes is called a carcinogen.

->Reteroviruses are RNA viruses which, when they invade animal cells, use the enzyme reverse transcriptase to make DNA copies of the viral RNA. The DNA is inserted into the host DNA where it may stay and be replicated for generation of cells. HIV is a harmful reterovirus and other reteroviruses cause cancer. These contain a gene which alters host cell division genes, switching them on and causing the cell to become malignant.

->DNA viruses contain DNA as their hereditary material. Some contain their own oncogenes which can cause uncontrolled cell division of host cells.

->Hereditary predisposition. About 5% of human cancers show a strong genetic predisposition. More than 40 types of cancer, including breast, ovary and colon cancers come into the category. The genes responsible may be oncogenes, or genes which lead to failure to kill cancer cells.

->Ionising radiation. This includes X-rays, Gamma rays and particles from the decay of radioactive elements. The radiation causes the formation of chemically active and damaging ions inside cells which can break DNA strands or cause mutations. Ionising radiation causes skin cancer, bone marrow cancer, lung cancer and breast cancer.

->Ultraviolet light. DNA absorbs ultraviolet light and the energy is used in converting the bases into more reactive forms which react with surrounding molecules. Sunlight contains ultraviolet light and prolonged exposure to it can result in skin cancers and commonly causes death through secondary brain tumours.

->Radon gas is a natural source of radiation released from certain rocks such as granite. It has been linked to the development of leukemia(cancer of white blood cells), lung, kidney and prostate cancers.

->Chemical mutagens. Many cancers are now recognised as causing cancer. Soot and coal tar develop cancer of the scrotum. Mineral oils are also founf to be carcinogenic. Some cause cancers of the abdonimal wall and bladder cancer.

Inorganic arsenic compounds produce skin cancer and abestos products cause lung cancer. Tobacco smoke contains chemicals responsible for lung cancer.

The Course of Cancer

Cells go through a series of changes before turning cacerous.

Step 1 A mistake happens in the cell..

Sooner or later, exposure to ultraviolet light, chemicals from the environment or even the byproducts of normal mtabolism changes one of the genes in a cell. In most cases this does not lead to cancer.

Step 2 ..the mistakes add up

It becomes harder and harder for the cells to maintain normal growth, as genes that shoild be ‘on’ get turned ‘off’ and genes that should be ‘off’ are turned ‘on’.

1) DNA-REPAIR GENES

These genes make proteins that correct the errors that sometimes occur whenever a cell copies its DNA. If repair genes can’t do their job, genetic mistakes start to accumulate.

2)TUMOUR-SUPPRESSOR GENES

These restrain cells growth and division. Their absence or inactivation takes the brakes off cell multiplication.

3)GROWTH GENES

If the genes that regulate normal cell growth and division become stuck in the “on” position, growth continues unbated.

Step 3 ..the cells turn cancerous

Free of normal restraints, the now malignant cells break all the rules. They divide uncontrllably, become less attached to their neighbours and invade the space occupied by normal cells.

Step 4 ..the tumour’s apetite grows

In a process called angiogenesis, malignat cells secrete chemicals that attract and promote the formation of new blood vessels. With a steady supply of nutrients, the tumour can grow without limits.

Step 5 ..the cancer spreads

Pieces of the tumour break off and, in a process called metastasis, migrate through the blood and lymphatic systems. Eventually the runway cells colonize other parts of the body and give rise to distant tumours.

Prevention and Control

There must be constant vigilance in the workplace regarding the possible dangers of exposure to carcinogens. The general public and workers should be made aware of any problems that may exist. Educational campaigns can encourage indiviuals to pay attention to early signs that may indicate the presence of cancer. Early diagnosis is important for increasing the chances of successful treatment.

Control should be considered as:

->prevention- protection against known carcinogens;

->early diagnosis- including screening programmes;

->treatment-urgent action once diagnmosis is made.

Traetment includes starving the tumour. As a cancer tumour grows, it builds its own network of capillariesthat tap into body’s blood suplly and draw on the oxygen and nutrients the tumour needs to survive. Ant-angiogenesis block the formation of new vessels and cut the tumour off from its blood supply. Gradually, malignat cells die and the tumour starts to shrink.

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Tagged with: cancer colorectal, division, hereditary predisposition, Lung, rna viruses

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November 25th, 2010 | Category: Cancer concern | 2 Comments »
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