What is the most prolific cancer?

Prolific?: If you mean the cancer that grows most rapidly, this would probably be some of the acute myelogenous leukemias. If I have misunderstood your question, please rephrase it and one of the healthtap folks will be glad to give a better answer.

U mean common?: Worldwide ... Nonmelanoma skin cancer is most common followed, in the us, by lung cancer, breast/prostate cancer, and colon cancer. Fortunately a good screening program can catch most of these early. Prevention by not smoking can curb lung cancer risks.

Depends on quest: There are global estimates by who. However, the following links will give you usa stats/estimates: http://goo.Gl/guwxr and http://goo.Gl/tcqe4 and http://goo.Gl/kjuqk and http://goo.Gl/sw3ev.