Good prognosis. It likes to spread usually locally first, so it needs to be treated locally. Prognosis depends on stage and extent of disease involvement. In very advance stage it can metastasize to other organs.
It depends... Vaginal cancer size (of the tumor) and severity (of the changing cancer cells) play a huge role in prognosis. Pre-cancerous and early cancerous vaginal lesions are usually curable. The best bet is to catch it early, be treated by a gyn-oncologist and follow their recommendations.