[1] Singapore Gen Hosp, Dept Gen Surg, S-169856 Singapore, Singapore
[2] Duke NUS Grad Med Sch, Canc & Stem Cell Biol, S-169857 Singapore, Singapore
[3] Natl Canc Ctr, Div Surg Oncol, S-169610 Singapore, Singapore
[4] Natl Canc Ctr, Canc Therapeut Res Lab, S-169610 Singapore, Singapore
[5] Singapore Gen Hosp, Dept Anat Pathol, S-169856 Singapore, Singapore
[6] Natl Canc Ctr, Dept Med Oncol, S-169610 Singapore, Singapore
[7] Singhealth, Singhlth Duke NUS Head & Neck Ctr, S-169856 Singapore, Singapore