About the skin damage thing, thanks for all these stories. it's really helpful.
I'm not sure, but biologically I think that this is what's going on:
With "skin damage" I think that means that sunshine has damaged the DNA in the cells so that the cells then grow a bit wrong. This increases the risk that further damage to the DNA will turn them cancerous, so the GP wants to kill those cells. This is done by putting on a cream, which I think triggers a natural process called programmed cell death, which is why the cells die and then peel off. As far as I can tell, it's basically a milder form of what happens when we put bazuka cream on a verruca-ish.
In the case of Jam's dh who had non-malignant cancerous cells on his hand (I do remember Jam and I'm so glad that got all sorted for you), I think that means that the cells had made the next step to become cancerous, which I think means that they had started multiplying in number very rapidly, which is why the lump grew in size. However, I think that the cancer was considered non-malignant, because the particular cell type was not able to travel from its current location to other locations in the body. This ability to travel is called being "motile" and so these were non-motile cells. If the cancer can't travel, then it can't go and make little lumps in other parts of the body, which is very important. A non-travelling cancer is relatively safe as it is just sitting there growing on the hand, where it started. It can just be cut off, and everybody is happy.
Malignant cancer is different. This is when a cell's DNA gets damaged and the cells start dividing (multiplying in number) very rapidly like benign cancer. But also the cells are the kind that can travel through the body and makes lumps in other locations. The new lumps can block important pipes or press hard against important other body parts. These other places might be places where the lumps would block tubes in places like the lungs and the brain and the spinal column. That is when malignant cancel has started and why it is a problem.
Does that seem right? I 'm a scientist, but I know mainly about plants, and cancer is really never a problem in plants, because plant cells can't travel. They just never really figured out how to do that.
I hope I have explained that sensitively enough, and that I have got it right. I know this is a thing that touches us all through family, or through our own experience. 

to all those who are dealing with it now or in the recent past. 
