Yes, it could.
How old are you?
Brown spots on older caucasian faces are called 'liver spots' and are due to pigment changes, poor diet, sun damage and genetics. You can bleach them, usually with mild acid night creams sold for that purpose. They work, but they'll make sun damage much worse if you don't wash them off in the morning and if you continue to be out in the sun without protection.
Yes, of course it may be cancer. You should talk to your doctor about seeing a dermatologist (your doctor should be able to say 'yes, this probably needs to be checked' or 'no' without needing a specialist).
at 4:11 PM on Nov. 15, 2010