Ron Silver's suffering is at an end. His passing Sunday ended a two-year long bout with esophageal cancer. He used to say that it was his curse to have been stricken with a type of that terrible disease that was so exotic that few people - and, until he came along, few if any celebrities - had contracted it. As a result, victims with cancer of the esophagus had no lobby generating large research and development budgets aimed at producing a cure.