Surge = increasing I think in this case the sentence means : The skin cancer rates has improved since 70s I hope i'm clear in my explication.

A surge is a powerful thrust of force. A surge of water / energy / a crowd. In your example, it means "increased strongly/dramatically". It's not a positive thing in any way.

应该是急速上升一类的意思，surge本身有汹涌，急速而来的意

Thank you very much. Leigh Mumford.

Surge does mean to increase. The sentence means that the number of skin cancer cases/patients have increased in a big way since the 70s.