"There is no scientific evidence that a lightning strike can awaken dormant cancer. The documented effects of a lightning strike are primarily neurological, cardiac, and thermal — including brain injury, seizures, cardiac arrest, burns, and long-term cognitive issues — but none of the medical literature links the electrical discharge to reactivating dormant tumor cells.
While research (e.g., from the Wistar Institute) has shown that stress hormones can awaken dormant cancer cells, the extreme acute stress of a lightning strike has never been shown to produce this effect in any documented case. The mechanism identified involves sustained elevation of norepinephrine and specific proteins (S100A8/A9) in immune cells over time, not a single electrical event.
There are a few unverified anecdotal reports of lightning "curing" chronic conditions (including one 1932 claim of cancer remission), but these are not supported by medical evidence and are considered coincidences or misdiagnoses."