Dr K C Tan graduated from the Medical Faculty, University of Malaya, in 1978 and obtained his Fellowship of the Royal College of Surgeons of Edinburgh in 1982. From 1984 to 1985, he obtained advanced training in paediatric surgery in Manchester and Southampton, UK. He obtained further training in paediatric hepatobiliary surgery and liver transplant surgery in King's College Hospital (KCH), London from 1986 to 1994.

Among the 400 liver transplant operations which he had performed in the UK, many were procedures that were carried out for the first time in the UK. He pioneered the first 'split-liver' transplant operation in which a donor graft was divided and transplanted to two recipients. He also performed the first auxiliary heterotopic liver graft for a patient with fulminant hepatic failure. A pair of siblings with Crigler-Najjar syndrome was successfully given orthotopic segmental grafts, the first such operation in Europe and the second time it had been performed in the world. He performed five combined liver-kidney and two combined heart-liver transplant operations, the latter a collaborative effort with Professor Sir Magdi Yacoub of Harefield Hospital, London.

Although the Liver Transplant Programme in KCH was largely adult-based, he performed over 75 paediatric liver transplants, 45% of which were liver reductions from an adult liver. He successfully completed the first pilot study on paediatric living donor liver transplantation (LDLT) in the UK.

During his tenure as the Senior Liver Transplant Surgeon at KCH, he trained 26 surgeons in hepatobiliary and liver transplant surgery. He advised and helped implement the Irish National Liver Transplant Programme in St. Vincents Hospital, Dublin.

Dr Tan returned to South-east Asia in 1994 after six years as Consultant Surgeon in KCH to set up private practice, the Asian Centre for Liver Diseases & Transplantation, in Gleneagles Hospital, Singapore, and the Subang Jaya Medical Centre (SJMC), Kuala Lumpur, Malaysia. He started a LDLT programme in SJMC in 1995 where to-date, over 50 transplants have been performed. It was here that he performed the South-east Asia's first paediatric LDLT on 23rd March 1995.

In 1996, he was appointed Director of the Liver Transplant Programme, National University Hospital (NUH), Singapore. He performed 47 transplants, both adult and paediatric, at the NUH before he left in March 2002.

In January 2002, Gleneagles Hospital, Singapore, was given permission to perform LDLT. The first successful adult-adult LDLT in South-east Asia was performed in Gleneagles in April 2002. Dr K C Tan and his team have successfully performed more than 170 LDLTs - the only private centre in South-east Asia to reach this historical milestone.

Dr Tan has published and lectured extensively on the subjects of hepatobiliary and liver transplantation surgery. He co-edited a textbook on 'The Practice of Liver Transplantation'. Dr Tan has continued to train young surgeons from Asian countries in the field of hepatobiliary and liver transplant surgery. Many have returned to set up similar centres in their home countries.