You most likely have no cause of action. To recover money, there must be a causal link between the incident or occurence and the injury; this causal link must be supported by--in cases like this--scientific or medical evidence, accepted by the mainstream scientific/medical community as reasonable, as to how the incident caused the injury. To the best of my knowledge, there is no credible evidence showing a link between being burned, whether by a cell phone or otherwise, and breast cancer; without being able to prove that link, there is no cause of action.