Cervical screening scandal victim Vicky Phelan has told TDs: "If I do die, I want it not to be in vain."
Giving evidence to the Dail's Public Accounts Committee (PAC), Ms Phelan said she is "not interested in revenge", but wants to see "accountability" and the HSE overhauled "from the ground up".
The terminally ill mother of two - who was told her 2011 smear test was normal, only to be diagnosed with cancer three years later - also called for a commitment that the failures exposed will never happen again.
She was joined before the PAC by Stephen Teap, whose wife Irene (35) died from cervical cancer last year, despite her smear tests in 2010 and 2013 being reported as normal.
The scandal over cervical screening was exposed last month after details of Ms Phelan's legal action against a US lab contracted to process the tests by CervicalCheck emerged. She was awarded €2.5m in damages.
Ms Phelan, from Annacotty, Co Limerick, only discovered her 2011 smear was incorrect when she was told late last year that the cancer she was treated for in 2014 had returned.
She was told the disease had spread, affecting vital organs, and was now terminal.
She began her legal action in January, and discovered that there was 15 months of correspondence about who would tell her about the incorrect smear test.
Ms Phelan told TDs: "The misdiagnosis in my case has cost me my life. I've got terminal cancer. I don't believe I'm going to die, but I have to fight for my life every day."
She said the incorrect 2011 smear was either a result of incompetence or it was not looked at at all as it was "full of cancer".
In powerful testimony, father-of-two Mr Teap said women have been "handed death sentences".
He said two opportunities to diagnose his wife's cancer were missed, and if they had not been "she would have been with us here today".
Both Mr Teap and Ms Phelan spoke of the need for those responsible for the scandal to be held to account.
Mr Teap told the committee that he believes more officials in the health service need to step aside from their positions while the inquiry into the scandal is carried out.
He added that it looked to him as if information was withheld from ministers and that people in senior positions knew about controversial HSE memos about the cervical screening audit from 2016.
The PAC is examining the failure to inform 209 women who have cancer of the outcome of false negative smear tests which emerged in an audit of the CervicalCheck service.
Mr Teap, from Cork, also said there had been no support services for him to help his children Oscar (5) and Noah (3) through their bereavement.
He said that years from now the children will read the coverage of what happened to his wife and of his appearance before the committee.
He asked: "What is there to help me prepare them for that? What is there when they see two opportunities to save their mother's life missed?
Mr Teap said there are 17 families in the same situation, a reference to the other women who have died.
He also criticised the HSE, saying a "lack of open disclosure is clearly an issue".
Ms Phelan and Mr Teap also said they want a "random" audit of all CervicalCheck smear tests over the past decade to find out if more women have been affected.
Mr Teap said it would "alleviate the fear of women in Ireland".
Meanwhile, President Michael D Higgins visited Emma Mhic Mhathuna, a mother-of-five who was diagnosed with terminal cervical cancer after an abnormal smear test in 2013 was missed.
The president and his wife, Sabina, went to Ms Mhic Mhathuna's home in Kerry for the meeting.
Last week, she called him "the only person who could do something" to deal with the cervical cancer scandal.
After the meeting, she said: "He didn't have to come all the way down here and he did. It has made my own journey a little bit easier and he gave some comfort to my children."
Mr Higgins described his meeting with Ms Mhic Mhathuna as "valuable and wonderful".