New Zealand and Australia are the two most dangerous places on earth to contract skin cancers. Most likely because of a massive hole in the ozone layer for much of the summer months. Melanoma is the most dangerous form of skin cancer - a significant number are fatal.
I was diagnosed with minor skin cancers a few years ago. One was burnt out,another cut out, and the other was left to fade out.
According to the linked article, UV photos can reveal the full extent of sun damage, but not any under-lying cancer itself. Actually I have another brown mark on my right forearm to check out. Most likely nothing to worry about.
When I was a child in the 1950's it was cover up, wear hats etc. By the time I was a teenager in the 1960's, nobody gave a damn. Strip and sunbath; sunburn is nothing - it will lead to a lovely tan. Yeah right!