The National Comprehensive Cancer Network (NCCN) is a group of leading doctors and scientists from around the United States who have come together to figure out the very best way to help people with cancer. They meet regularly and look at medical studies, individual patient cases, and treatments that have been used before, and agree on the best treatments to suggest for different types of cancer. This helps doctors around the country treat their patients effectively with up-to-date, scientifically-proven methods.