If you're planning to hit the tanning salon for a little bronzing before an upcoming event, you may want to think again.  There's been a dramatic rise in skin cancer among women under the age of 40.  Melanoma cases increased eightfold in women between 1970 and 2009 and fourfold in men.  That's according to research from the Mayo Clinic.

"The use of tanning beds became increasingly popular in the late 1980s.  If there was a link between cancer and tanning beds, you'd start to see melanoma rates also increase in the group that are using them and that's exactly what we are starting to see," said Dr. Jerod Stapleton, Assistant Professor at Robert Wood Johnson Medical School and the Cancer Institute of New Jersey. 

"There is some evidence that even one tanning bed use can increase your risk of skin cancer.  It can definitely cause permanent skin damage which may not show right away, but as you get older," said Stapleton. 

So, what can you look for if you notice a spot on your skin?  "There is something we call the A-B-C-Ds of melanoma," said Stapleton.  "If a spot is asymmetrial, has a jagged border, an unusual color or its diameter is bigger than a pencil eraser, chances are, you should get it checked out."