Does white spots on my shoulders from sun mean its skin cancer or a sympton of it?

Let me guess... You are a blonde or red-head. That is a common problem for us. My avatar notwithstanding, I am actually a natural blonde and have quite a few of those white spots. They are basically skin cells that have little or no melanin... the chemical that causes tanning and our natural skin color. They do NOT mean you have skin cancer, but it does mean you are more at risk for it than darker skinned people.

Take proper precautions when you are in the sun.

See a doctor if your concerned. I think it is in your pigment that shows up when you get darker or tan. Or it could be a skin called vitiligo (vit-ill-eye-go). Vitiligo most commonly affects the hands and feet, or around the eyes, ears, and mouth, but may be found all over the body. Although it may simply develop on its own, sun damage can definitely contribute to it. Some doctors even believe that the condition may be an autoimmune disease. This means that the body's defenses against germs are turned against the body itself.
But I am seriously not sure, see a doctor!

Skin Cancer comes in various shapes and forms and levels of danger. They seem to have one thing in common though, and that is a multi-colored and unsymmetrical shape. Keep an eye on these spots over the next week or two and see if they change at all, and go see a dermatologist. I had skin cancer on my face a couple of years ago, and since, I go see the doctor every six months to be safe. If it is cancer, its better to catch it early.