The move of upper gastro-intestinal cancer surgery from Cornwall to Devon is be reviewed.
An independent panel will consider whether the changes provide a safe, sustainable and accessible service.
The review will be carried out by the Independent Reconfiguration Panel (IRP) - an expert which investigates NHS service changes for the government.
Surgery moved from the Royal Cornwall Hospital in Truro to Plymouth's Derriford Hospital on 1 January.
Following an initial assessment by the IRP, Health Secretary Andy Burnham has accepted its advice that a full review should be undertaken.
The review will be led by Dr Peter Barrett, chairman of the IRP.
"Our job is to consider whether the changes provide the highest possible quality of care for patients," Dr Barrett said.
"We will be gathering evidence locally to ensure the recommendations we make are in the best interests of local people.
"Each review we undertake is unique and it is therefore important that we listen to all sides of the debate to inform our review."
The IRP will meet patients, clinicians and other staff in Cornwall.
'Centres of excellence'
It will also visit NHS facilities in both Devon and Cornwall and hold meetings to hear directly from interested parties.
The IRP will make its recommendations to the Health Secretary by 4 June and the final decision on changes to services in the area will then be made by Mr Burnham.
There was strong opposition to the move when it was first announced, with opponents saying people in rural areas would suffer.
The NHS maintains that regional centres of excellence are the best option for patients and offer better levels of care and the switch was part of a move to centralise cancer services in the two counties.