Cancer causes approximately one third of all deaths in industrialized countries. Might this be some association with "industry."
Here are the number of cancer deaths per age group, in the US in 1985.
|
|
|
| <15 | 1,042 |
| 15-34 | 4,029 |
| 35-54 | 25,733 |
| 55-74 | 136,869 |
| >75 | 79,220 |
The incidence of cancer increases with age. The decline in total cancer deaths in the over 75 age bracket is because there are less people that age. We don't think of aging as a cause of cancer, but it is clearly associated with it. In the non-industrialized world, the average lifespan is much less. People in those countries die of infectious diseases, nutrition related problems, warfare, and lack of medical attention in much greater proportion than people in the industrialized countries.
It turns out the increase in cancer deaths with aging follows from what we know about cancer. In Tox Tutor you learned that cancer can thought of as developing in stages:
If you are interested (it is not required) I have put a document in the Course Documents folder that deals with the origins of cancer. It is a copyrighted article, so you may use it in conjunction with this course, but not recopy it or distribute it to others.
Note that in the table above, mutations are required for the stages. Let's talk a little more about mutations. NEXT