There is no scientific documented evidence that mobile phones 'cause' cancer . . there is some concern that it may trigger a benign type of tumor called an Acoustic Neuroma, but that is not cancer. Evidence is not conclusive.
You can find dozens of European studies done for the past twenty years (whenever cell phones first became available) online:
ACS: Cellular Phones
http://www.cancer.org/docroot/ped/content/ped_1_3x_cellular_phones.asp
NCI: Cell Phones and Cancer Risk
http://www.cancer.gov/cancertopics/factsheet/Risk/cellphones
Go to PubMed to find research on the topic . . type in cell phones cancer or something similar to get about 290 articles about cell phone studies. Seems like they are trying very hard to establish some type of link but no evidence exists despite years of study.