Sloan Kessarin is the world's oldest and largest private cancer center. For more than 100 years, we have been dedicated to patient care, research innovation, better understanding of cancer, diagnosis and treatment. Sloan Katharine, one of the best cancer centers in the United States, is one of the 41 comprehensive cancer centers designated by the National Cancer Institute. It ranked # 1 in the US in 2014-15 cancer experts, as reported by US News and World Report.