Some 7,000 people turned out in Castlebar, Co Mayo, yesterday in support of a campaign to maintain specialist cancer services in the northwest.
Consultant surgeon Kevin Barry told the rally that Mayo General Hospital could provide survival figures as good as any of the eight proposed "centres of excellence".
The new national cancer control programme has identified eight specialist cancer centres, based in each of the four Health Service Executive (HSE) areas, to provide an integrated treatment service - including diagnostic, surgical, medical and radiation oncology services - for all forms of cancer.
Some 13 regional centres have been asked to discontinue breast cancer surgery immediately, and others, including Mayo General Hospital and Sligo General Hospital, have been asked to do so on a phased basis.
Mr Barry, consultant surgeon at Mayo General Hospital for the past eight years, pleaded with the campaigners - who converged on the ballroom of Castlebar's TF Royal Hotel, following a march through the town - to keep the momentum of protest going for the next 12-18 months.
He said the huge turnout would help boost the morale of staff at the cancer unit in the hospital, where some 79 cases of breast cancer involving operations had been dealt with so far this year.
Another speaker at the post-march rally, Ballina-based GP Dr Paul Nolan, said the unit in Castlebar was the envy of other regions. He warned of a domino effect if the cancer unit was to close, with other services being lost also to University College Hospital Galway (UCHG).
Fine Gael leader Enda Kenny said there were many women walking around Mayo today who owed their lives to the professional assessment, diagnosis, treatment and aftercare that had been provided by Mr Barry and his team for many years.
He added that if Mr Barry was moved to Galway in the morning he would be the fifth member of a team, doing fewer procedures than he was doing at the moment.
UCHG is one of the eight centres of excellence and one of two for the west, along with Limerick Regional Hospital.
Mr Kenny said the Government had gone ahead with its plans to dismantle the existing cancer treatment network without any consultation, in the same way it hadn't consulted the Garda when making the "daft decision" on provisional licence holders.
The Fine Gael leader maintained the ultimate weapon would be if Fianna Fáil members of the Government had the courage of their convictions and told the Taoiseach they would not support him beyond Christmas unless he gave them a written guarantee on the hospital issue.
Other speakers at the rally included Mary McGreal of the Mayo Cancer Network; Independent TD Beverley Flynn; Fianna Fáil TD Dara Calleary; Fine Gael TD John O'Mahony; and the chairman of Mayo Co Council, Séamus Weir.
Fine Gael TD Michael Ring could not attend because of an overseas political commitment but sent a message of support.
Ms Flynn said every politician in the region was 100 per cent behind retaining the existing cancer services in the region, while Mr O'Mahony said it behoved every elected representative in the county to stand firm on the issue.