What causes cancer?

There is no one single cause for cancer.

Scientists believe that it's the interaction of the many factors along that produce cancer.

The factors concerned could also be genetic, environmental, or constitutional characteristics of the individual.

Diagnosis, treatment, and prognosis for childhood cancers square measure completely different than for adult cancers.

The main differences are the survival rate and the cause of cancer.

The overall five-year survival rate for childhood cancer is concerning eightieth, while in adult cancers the survival rate is 68%.

This distinction is assumed to be as a result of childhood willcer is a lot of awake to medical care and a baby can tolerate a a lot of aggressive medical care.

Childhood cancers typically occur or begin within the stem cells, which are simple cells capable of producing other types of specialized cells that the body needs.

A discontinuous (occurs by chance) cell modification or mutation is typically what causes childhood cancer.

In adults, the kind of cell that becomes cancerous is typically AN vegetative cell.

Epithelial cells line the body cavity and canopy the body surface.

Cancer happens from environmental exposures to those cells over time.

Adult cancers square measure generally named as none heritable for this reason.

The discovery of pure forms of genes that contribute to cancer has been an especially vital development for cancer analysis.

Over ninetieth of cancers square measure discovered to own some sort of genetic alteration.

Some of these alterations square measure transmissible, whereas others square measure discontinuous, which means they occur by chance or occur from environmental exposures (usually over many years).

Types of cancer genes

There square measure 3 main forms of genes that may have an effect on cell growth and square measure altered (mutated) in sure forms of cancers, including the following:

•Oncogenes: These genes regulate the normal growth of cells.

Scientists unremarkably describe oncogenes as the same as cancer "switch" that the majority of individuals have in their bodies.

What "flips the switch" to form these oncogenes suddenly become unable to regulate the conventional growth of cells and permitting abnormal cancer cells to start to grow, is unknown.

•Tumour suppressor genes: These genes are able to recognize abnormal growth and reproduction of damaged cells or cancer cells, and can interrupt their reproduction until the defect is corrected.

If the growth suppressor genes square measure mutated, however, and they do not function properly, tumour growth may occur.

•Mismatch-repair genes: These genes help recognize errors when DNA is copied to make a new cell.

If the deoxyribonucleic acid doesn't "match" utterly, these genes repair the couple and proper the error.

If these genes don't seem to be operating properly, however, errors in deoxyribonucleic acid are often transmitted to new cells, causing them to be damaged.

Usually the number of cells in any of our body tissues are tightly controlled so that new cells are made for normal growth and development, as well as to replace dying cells.

Ultimately, cancer may be a loss of this balance thanks to genetic alterations that "tip the balance" in favour of excessive cell growth.

Cancer is caused by accumulated damage to genes

Such changes could also be thanks to the likelihood or to exposure to cancer inflicting substance.

The substances that cause cancer are called carcinogens.

A matter could also be a chemical substance, such as certain molecules in tobacco smoke.

The explanation for cancer could also be environmental agents, viral or genetic factors.

We should bear in mind, though, that in the majority of cancer cases, we cannot attribute the disease to a single cause.

We can roughly divide cancer risk factors into the subsequent groups:

1.biological or internal factors, such as age, gender inherited genetic defects and skin type

2.environmental exposure, for instance to radon and UV radiation, and fine particulate matter

3.occupational risk factors, including carcinogens such as many chemicals, radioactive materials and asbestos

4.lifestyle-related factors.

Lifestyle-related factors that cause cancer include:

•tobacco

•alcohol

•UV radiation in sunlight

•some food-related factors, such as nitrites and polyaromatic hydrocarbons generated by barbecuing food).

Lifestyles can prevent cancer

Cancer inflicting factors associated with work and living environments include:

•asbestos fibres

•tar and pitch

•polynuclear hydrocarbons (e.g. benzopyrene)

•Some metal compounds

•Some plastic chemicals (e.g. Vinyl chloride)

Bacteria and viruses can cause cancer:

•Helicobacter pylori (H. pylori, which causes gastritis)

•HBV, HCV (hepatitis viruses that cause hepatitis)

•HPV (human papillomavirus, papillomavirus, which causes changes eg. Cervical cells)

•EBV (Epstein-Barr virus, the herpes virus that causes inflammation of the throat lymphoid)

Radiation can cause cancer:

•ionising radiation (e.g. X-ray radiation, soil radon)

•non-ionised radiation (the sun’s ultraviolet radiation)

Some drugs may increase the risk of cancer:

•certain antineoplastic agents

•certain hormones

•medicines that cause immune deficiency

In 5 – 10 per cent of breast cancer genetic predisposition plays an important role in the emergence of the disease