Memorial Sloan Kettering Cancer Center (New York City). Providing patient care for more than 130 years, Memorial Sloan Kettering Cancer Center is the oldest and largest private cancer center in the world. The center has more than 12,900 employees, which includes 935 attending physicians and 2,221 registered nurses. Memorial Sloan Kettering received the Employee's Choice Award from Glassdoor in 2016 and 2017, which honors the best places to work in North America and parts of Europe. In 2016, Memorial Sloan Kettering was recognized as a leader in LGBT healthcare according to the Healthcare Equality Index by the Human Rights Campaign. The center offers employees a number of benefits, including tuition reimbursement; backup child and elder care; adoption reimbursement; and staff, management and leadership development programs.