A Thought Reguarding Cancer

[Sal The Butcher]

There are claims that certain activities increase the chances of obtaining cancer, but there are those who dispute this claim...


I have divised a theory based on no medical information other then my own undetrstanding of what cancer is. From what i understand cancer is no more then a single cell that develops with a mutation which causes it to reproduce at a more frequent rate then it should, which produces a tumor as every cell that comes from it will have that same mutation present.


Perhaps the chance for cancer is allways present, and perhaps the only thing that can make its development more probable is more reproduction by the bodies cells. I believe the cells in a persons body will have to reproduce more frequent;ey if that person is constantly damaging the cells.



now (ARBITRARY NUMBERS)

say there is a 1-1,000,000 chance of developing cancer every time a cell reproduces and on average it happens 10,000 times a day

now imagine someone who smokes, and thier lung tissue needs to be replaced more often, and the reproduction occurs 15,000 times a day

or someone who sunbathes and thier skin cells are damaged, which leads to reproduction occuring 20,000 time a day


is there any credibilty to this theory at all, as i have NO medical knowledge, i was just wondering one day how smoking could make cancer more likley without have some type of ablity to cause cells to mutate, and this is a theory i came up with

[Capsid]

You've pretty much nailed it, in that there is DNA damage (mutation) but normal cells die in a programmed way (apoptosis) and cancer cells do not. So it's not difference in cell reproduction (division) but whether they undego apoptosis or not.

http://en.wikipedia.org/wiki/Cancer

[casebro]

And your intestinal lining is sloughed off every day, bones are regenerated constantly, muscles too. Cells are worn out and replaced constantly. So the root cause of cancer is not the cells malfunctioning, but the fact that the body's defenses don't eliminate those bad cells. It's sort of a lack of an immune response. Too much immune response causes other probs, like arthritis, lupus, asthma, maybe heart disease. All caused by the body attacking good cells.

With up to date scanning possible today, it is felt that we can find growths sooner than the body can, but the body would take care of most of them in time, before illness is caused. Greater minds than yours or mine have been working in this field for long times.

[Dogdoctor]

There is more than just the numbers of cells undergoing mitosis. There is damage that occurs besides just the off chance of cancer developing when a cell divides.

[Capsid]

So the root cause of cancer is not the cells malfunctioning, but the fact that the body's defenses don't eliminate those bad cells. It's sort of a lack of an immune response.
The danger model (http://en.wikipedia.org/wiki/Polly_Matzinger/)for Immunology regards cancer cells as healthy and are therefore not eliminated.

[Dogdoctor]

My view is that the mutated cells avoiding the immune system is why they are cancerous not that the immune system fails. There is damage to DNA and it causes the cells to grow abnormally and the changes aren't recognized by the normal immune system . By the way the author of the danger model http://en.wikipedia.org/wiki/Polly_Matzinger is interesting although sounds wacky.
ETA: there are certain cancers which are more likely with suppressed immune systems but the majority are not.

[Cynric]

now imagine someone who smokes, and thier lung tissue needs to be replaced more often, and the reproduction occurs 15,000 times a day

or someone who sunbathes and thier skin cells are damaged, which leads to reproduction occuring 20,000 time a day

is there any credibilty to this theory at all, as i have NO medical knowledge, i was just wondering one day how smoking could make cancer more likley without have some type of ablity to cause cells to mutate, and this is a theory i came up with

Others have made excellent points, but it should be pointed out that both carcinogens in cigarette smoke and UV light directly damage DNA, increasing the rate of mutation. So, as well as increasing the turnover of cells (with the risk of proof-reading errors), the chance of transforming a 'normal' cell into a cancer cell is also greatly increased.