It's clear something has changed to make our environment more cancerous. Overall cancer incidence increased 48 percent between 1950 and 1990, according to the National Cancer Institute. That includes a 33 percent increase in childhood brain cancer, a 52 percent increase in breast cancer and a 134 percent increase in prostate cancer.
As a recent Biology major I've read dozens of case studies where they believe the cancer rates are staying the same and the increase is due to better doctors and more men going to the doctor. Let's face it two things are true. People go to the doctors more and detection methods are now better (than in 1950), which means that doctors can find more cases.
On another note an example of how this can seem silly...
I know what causes crime -- Ice Cream.
In the winter it's statistically proven that there is less crime in the colder months of the year. It's also a fact that less ice cream is sold in the winter months of the year. In the summer Ice Cream sales take off and so does the crime rate. Therefore I conclude that ice cream causes crime. ;)