Conversation: The conversation between human and AI assistant.
[|Human|] my father has a black spot in his mouth between the gum and cheek line.  He used to be a smoker but has quit for 25 yrs.  but did smoke for 30 yrs.     he also had radiation for a tumor behind his ear 3yrs ago.   Could this black spot in his mouth be cancer?
[|AI|]  Thanks for your question on Chat Doctor. I can understand your concern. Since your father was having ear cancer and past smoker, black spot in mouth may be the sign of early cancer. So better to consult doctor and get done clinical examination of oral cavity and black spot. If needed, biopsy and histopathological examination of the black spot should be done to rule out cancer. So consult doctor and discuss all these. Hope I have solved your query. Wishing good health to your father. Thanks.