Are there certain foods that can promote melanoma growth? i have read that alcohol intake and linoleic acid may have a role?

No specific foods: Once melanoma grows there is little to stop its spread. While UV radiation can effect the melanoma, no specific foods have a stimulating or regressive action on the melanoma. I do suspect that overuse of alcohol if it lowers the immune response would have a secondary effect on melanoma which is why compounds like steroids can cause all tumors to grow faster.

Probably not: I am not aware of any link between certain types of food and the promotion of melanoma growth.