Why/how does someone get cancer when there is no history of cancer on either side of the family?

Answer 1

Most cancers are the product of the person's environment - especially cigarettes and diet. 1/3 of all cancers are related to cigarettes and at least 1/3 are related to diet. Only about 10-15% of all cancers have a significant hereditary component (risk).

Answer 2

Cancer depends on two mutations.

The first mutation involves a mechanism which regulates cell growth. Many cancers start in epidermal tissue and these cell types divide constantly. However, they will stop dividing if the population reaches a specific size. Irritation kills cells and surviving cells then divide to replace dead ones. If the irritation is persistant, cell division is always happening. The irritation can then lead to a mutation which switches reproduction permenantly on.

The second mutation involves the cell's self destruct mechanism. Ordinarily cells regulate their own growth, but ocassionally need the help of other kinds of tissues. If there is a sudden increase in the amount of cells, growth is stopped when the immune system tags excess cells with a special marker. Macrophage cells then use it to triger the cell to release digestive enzymes which dissolves the cell. The macrophage can then absorb the cell contents and dispose of them. Tumors often become malignant when this second mutation ocurrs. The cells no longer respond either to their own growth regulation, nor the regulation of the immune system.

Lung, breast and colon cancer are all examples of cancers which probably develop in healthy tissue due to the influence of environmental pollution. Lung cancer is clearly the result of carcinogenic substances in cigarette smoke. Breast cancer can develop when artificial chemicals resembling estrogen overstimulate cells in breast tissue to reproduce. Colon cancer is probably the result of the buildup of waste material when low fiber diets do not allow the bowel to remove dead cells by ordinary abrasion.

How individuals respond to toxic chemicals is often a matter of which cytochromes they have in their particular biochemistry. Cytochromes are enzymes which combine various substances with oxygen, breaking them down. Some individuals have a broader range of cytochromes and can therfore handle a broader variety of toxins. The abundance of a particular cytochrome also varies according to individuals. This probably explains why some individuals can smoke all their lives and never develop lung cancer (however they still are prone to emphasema, due to destruction of the lungs). . Cytochromes also probably play an important role in a woman's chances of developing breast cancer, or the chances of getting prostate or colon cancer.

Truly genetic cancers I attribute to those which are caused by viruses. Leukemia has been linked to a particular virus and reciently cervical cancer has also been associated with a virus as well. Viruses take control of the cell's DNA and use their own genes to mass manufacture themselves. If functional bits of these genes become attached to succeptable cells, they could cause the cells to mass produce as well. However, this is purely a matter of genetic succeptability. The viruses responcible for leukemia and cervical cancer are widespread in the population, but do not universally cause cancer to develop in infected individuals.

Answer 3

There are all sorts of environmental factors that COULD lead to cancer.

Having no family history doesn't mean you're immune to cancer. It just means there is a slightly less chance of you developing said condition.

Answer 4

Cancer is, at it's simplest, cell mutation and uncontrolled growth. As others say, the environment can do that, exposure to certain chemicals or microbes, and sometimes for reasons no one can name.

Answer 5

Cancer is an equal opportunity disease. Any one can get it just like a cold but more deadly.

Answer 6

CANCER IS PROBABLY CAUSED BY CELL MUTATION ACQUIRED THRU THE FOOD WE EAT... LIKE FOR EXAMPLE FOOD THAT HAS MAY PRESERVATIVES LIKE JUNKFOODS, BURGERS, FASTFOODS,ETC. WHICH CONTAINS NITRATES WHICH MAY BE ABLE TO CAUSE CANCERS