mt. singabung, an active volcano under dangerous. sama mohsin, cnn, mt. > an alarming report by the world health organization saying cancer cases are expected to surge around the world in the next 20 years. >> our own doctor sanjay gupta looks at why this is happening and what the report says about what can be done about it. >> well, the prediction is pretty dire from the w.h.o. overall. if you look at the numbers, they say over the next two decades, they expect to see an increase, a surge, really, of 57% in terms of new cancer cases. look at the most recent numbers, 2012, 14 million new cancer cases. that's new cancer cases per y r year. they think by the year 2030, that number will go up to 22 million. again, new cases per year. part of this is expected. the population of the world is growing. we're getting older, as well. but i think what has surprised a lot of people, how much of an impact this has been on the developed world as opposed to developing world. there's a lot of recommendations in this paper from the w.h.o. about what we can all do to preve