MB ChB Edin 1948; FRCS Edin 1956; FRCS Eng 1958.
Cassie was born in Edinburgh on 1 April 1926. After studying at Edinburgh University, Cassie held positions at Cumberland Infirmary, Halifax General Hospital and Carlisle Maternity Hospital. In 1955 he was appointed senior house officer at MRI and went on to become senior registrar. Cassie was also a surgical tutor for the University of Manchester. He was later appointed honorary consultant surgeon to Burnley Hospital Authority.