Dr Tan Yah Yuen obtained her medical degree from National University of Singapore in 1995. She pursued surgical training after completion of internship and received post-graduate diplomas from the Royal College of Surgeons of Edinburgh and Royal College of Surgeons in 1999. She underwent advanced surgical training in Tan Tock Seng Hospital and received further accreditation in General Surgery from the Royal College of Surgeons of Edinburgh in 2003.

In pursuit of her interest in breast surgery, Dr Tan was the recipient of the HMDP scholarship awarded by the Ministry of Health and spent 12 months in subspecialty training in Breast and Endocrine Surgery at the University of California San Francisco in 2004. Upon return, Dr Tan Yah Yuen developed the sentinel lymph node program for early breast cancer in Tan Tock Seng Hospital using dual radionuclide and blue dye technique.

In 2005, Dr Tan joined the newly set up specialized Breast Unit in KK Women's and Children's Hospital (KKH), where she managed and treated solely breast diseases ranging from developmental and lactational problems to benign tumours and breast cancer. The dual technique sentinel lymph node program was also similarly set up by Dr Tan in KKH. Selective sentinel lymphadenectomy is now the standard of care for women with early breast cancer.

Dr Tan is also widely published in the field of breast surgery in several local, regional and international journals. She previously received a S$1million Ministry of Health grant to research the usefulness of mammary ductoscopy in women with pathological nipple discharge and breast cancer from 2007-2010. Dr Tan's other interests include minimally invasive techniques in breast surgery, including ultrasound guided vacuum assisted needle biopsies (mammotomy). In recognition of her efforts towards patient care, she was awarded the SPRING Singapore Excellent Service Award (EXSA) Silver, Gold and Star Awards from 2007-2009 respectively. Dr Tan is also a member of International Society of Surgery and Breast Surgery International.

Dr Tan Yah Yuen was previously Senior Consultant at the Breast Unit of KKH when she left in 2010 to begin her own private practice and this has allowed her to spend more quality time in managing the spectrum of breast disorders that have become more common in our modern society.