My sister was diagnosed in April '06 with rectal melanoma. They removed her lesion, and did nothing. She was checked (scanned) every three months, and up until July -07 was clear. In July they found that the melanoma had reocurred in the rectum with mets to her lung and liver. She is now in a clinical trial. I would highly recommend doing whatever you can early on, as your chances are much greater if you get a jump start on kicking this nasty cancers butt! I know your melanoma probably originated on the skin, but I would still recommend the interferon. We thought the "sit and watch" thing would be ok, it wasn't! I wish we had opted for the interferon early on.
God bless you!