My dad got a spot of melanoma removed on his chest. he said that the derm. got it all and it only hit the 1st layer. is there a chance it could have spread at this level? my dad is saying its nothing to worry about (from dr). what do you think?

Your dad and his dermatologist are right. Melanoma has a very bad reputation, which is well deserved: it is deadly when it spreads. But the actual overall mortality rate is low, because most melanomas are diagnosed early, as for your dad. That doesn't mean zero risk, but the chance it has spread or will be dangerous is low. If he has any doubt, he (not you!) can consult with an oncologist.

That is the best that can be done with our knowledge at this time. Your question and worries are understandable as melanomas are vicious diseases with sometimes unexpected devastating relapses. Keeping tight follow up with his dermatologist remains best in the long run.