The review will try to determine whether there were false negative results in original tests and whether cases should, in fact, have been reported differently to women.
There were shock revelations from the Health Minister Simon Harris this week that an extra 1,500 women had not had their cancer tests reviewed. This is on top of the estimated 1,482 cancer cases where reviews were done.
Mr Varadkar told the Dáil that all women with cancer over the last decade would now have their tests investigated and reviewed as part of a response to the tests scandal. The reviews will be completed in the coming weeks.
Speaking during leaders’ questions in the Dáil, he said: “To the women of Ireland, I want to say that I am determined to get to the bottom of this, to establish the facts and to restore confidence in our cancer-screening system.
“A number of actions have been agreed this morning. First, we are going to ask a team of expert international cytopathologists to carry out a clinical review and to look again at the smears of all the women who were diagnosed with cancer in the past 10 years.
“We do not have the exact figure but it is between 2,000 and 3,000. We will most likely find out that the majority of the additional 1,500, of whom we spoke yesterday, never had a smear test.
“The review will be led by the Royal College of Obstetricians and Gynaecologists, who will try to identify the genuine false negatives and those cases which should have been reported differently. We believe this can be completed by the end of May.”
But Mr Varadkar’s request for “time and space” to get on top of the scandal and assess the exact numbers of women caught up in the botched tests controversy was slammed by the opposition.
Fianna Fail’s Micheál Martin said it was over a week since dying mother Vicky Phelan’s shocking court case where it emerged her false negative cancer test remained unknown for years.
There was no one leading the response to the health scandal and ministers had “run to the hills”, it was added.
Sinn Féin’s Mary Lou McDonald reiterated that HSE boss Tony O’Brien must resign over the scandal ahead of his formal departure from the health service in August.
“It is a scandal that Tony O’Brien is left in his post for those weeks to sail into the sunset with a large pension and a hefty gratuity, having left a scene of devastation, upset and trauma behind him.
Ms McDonald insisted: “ If the Taoiseach is serious about leadership on this matter and if the Taoiseach was really serious about reassuring the women right across the State, he would do the first thing that needs to happen, which is to remove that incompetent man from the position he currently holds.”
Mr O’Brien had presided over “negligence” and “concealment” and cannot remain on, she said.
But the Taoiseach responded that “cock-ups were more common than conspiracy theories”.
Mr Varadkar also told of a second resignation over the controversy. He said the director of CervicalCheck is no longer in charge of the cancer-screening programme and that a team of international experts will look at the cases of the women who received smears in the past 10 years.
He also said: “We’re going to bring in more accurate smear tests and will be among the first in the world to do so.”
It would be logistically difficult and expensive but it would be done, he added.