What causes cancer?

Answer 1

Basically, cancer is an uncontrolled excessive abnormal growth of cells. It all started from any one cell in the body. There are many regulatory proteins and factors which control the normal growth of cells. Everyday, our body cells are exposed to mutations, and there is a repair mechanism to fix it. If they can't fix it, the cells are bound to die via apoptosis. Therefore, anything that causes a defect in this repair mechanism can cause the mutated cells to continue to thrive. this could be disastrous.

Another cause is due to certain defect in the signalling pathway in the cells which directs cell-division. In this case, the pathway over-stimulate cell division, causing uncontrolled cell division which leads to cancer.

Cancer is generally an accumulation of mutation in the cells which continue to thrive and causes harm.

As mentioned, anything that can cause mutation in the cells like certain chemicals and radiation are actually risk factors for cancer since it only increases the likelihood to get cancer.

Answer 2

Cancer starts when a gene known as p53 is destroyed. This is the gene that fixes dna that has been modified. Cancer is a disease of self, meaning that the body creates it and supports it. Some cancers illicit an immune response--this is a good thing meaning the body is fighting against this abnormal thing. Most cancers bear the markers of the body, so the immune system does not detect it. There are other things that have to happen on a genetic level to get a tumor to grow, initiating growth, vasculization, for example. Also, all cells are preprogrammed to die in certain circumstances, for example heart and brain cells die when oxygen is reintroduced after being deprived for a period of time, this is called apoptosis and is one of the things that gets turned "off" when a cancer begins. Many things can contribute to a cell having these series of events leading to cancer including variations in genetics, lifestyle and environment. As far as there being one "cause" there are many different types of cancer--around 230 identified and probably more.

Answer 3

very many things.
there are thousands of cancers, and only a few have been truly investigated.

in some cancers the cause is radiation- any radiation from x-rays, to ultraviolet rays (like sunshine) to even heat radiation.
this same radiation can be used to cure other cancers. radiation is also completely irrelevant in many cancers

viruses cause some cancers. some viruses are also researched as a possible cure

chemicals may cause cancer. other chemicals can cure it. most chemicals are completely inert.

even irritation (eg a broken tooth or constant scratching) can cause a type of cancer

thousands of possible causes, and thousands of possible outcomes.

If this is not just a general question, then you'll have to be more specific

Answer 4

There are more than 100 types of cancers; any part of the body can be affected.
In 2005, 7.6 million people died of cancer - 13% of the 58 million deaths worldwide.
More than 70% of all cancer deaths occur in low and middle income countries.
Worldwide, the 5 most common types of cancer that kill men are (in order of frequency): lung, stomach, liver, colorectal and oesophagus
Worldwide, the 5 most common types of cancer that kill women are (in the order of frequency): breast, lung, stomach, colorectal and cervical
Tobacco use is the single largest preventable cause of cancer in the world.
One fifth of all cancers worldwide are caused by a chronic infection, for example human papillomavirus (HPV) causes cervical cancer and hepatitis B virus (HBV) causes liver cancer.
A third of cancers could be cured if detected early and treated adequately.
All patients in need of pain relief could be helped if current knowledge about pain control and palliative care were applied.
40% of cancer could be prevented, mainly by not using tobacco, having a healthy diet, being physically active and preventing infections that may cause cancer.
Please see the web pages for more details on Cancer.

Answer 5

There is no one onset for cancer. Due the number of types of cancer depends on the contributing factors and causes. Check out this web site for more detailed information about specific cancers.
http://medlineplus.gov/

Answer 6

If scientists knew the complete answer to this question, we wouldn't have cancer anymore. What is known is that something causes normal cells to mutate and start growing an multiplying at an uncontrolled rate. Here's a good site that is easy to understand:

Answer 7

Well, depending on the type of cancer, a variety of things contribute to it. It could genetics, one's diet and activity level or a harmful activity, such as smoking. I'm not sure we know 100% why cancer exists though.

Answer 8

Bad diet, smoking, excessive alcohol abuse, genetics, other lifestyle factors (pollution, etc).

Its basically anything that could irritate cells, meaning they need to be encouraged to divide. So if you smoke you irritate your lungs, the cells need to replace themselves, and then they start multiplying out of control.

So if you have a cut on your arm and keep opening the scar and the cells have to keep replacing each other you are increasing your risks.

But all in all genetics are important enough that you should just live your life in sensible limits cos theres no guarantee either way

Answer 9

Sunlight,tobacco,diet,alcohol,large doses of radiation,chemicals,and genetics.

Answer 10

Sometimes it is hereditary, or it is caused if you hit yourself in the same spot very hardly for continous times.