There is no scientific evidence to prove that Aloe vera can help treat, prevent or cure cancer in people in any way.
Some laboratory studies have shown that a substance present in Aloe vera leaves can block growth of cancer cells, and some websites for natural healing of cancers share informations about usage and results (Aloe Vera is particularly effective in the treatment of skin cancers).

What type of skin cancer you have?
Have you already tried Aloe Vera cream?
For how long you are using it?

Actually Aloe Vera is a good sunscreen lotion. Aloe Vera gel is a common ingredient in many skin creams and lotions, cosmetics, and burn and wound ointments. When used on skin for minor burns or irritations, aloe gel is usually applied to the affected area 3 to 5 times a day.