Video report by ITV News Social Affairs Editor Penny Marshall
A breast cancer survivor says she has been left feeling "angry" after an NHS IT error meant that her illness might have been picked up sooner.
Helen Jarvis, 72, was one of 500,000 women in the UK between 68 and 71 who did not receive invitations to their final mammogram screenings between 2009 and 2018.
Earlier this year, she noticed a lump by chance, which was successfully removed in February.
Ms Jarvis told ITV News she was "angry" that an earlier screening could have meant more straightforward treatment, and possibly no surgery.
She was also critical of a breast cancer helpline, specially established in the wake of the error, which took over an hour to connect to.
The NHS and Government have found themselves under criticism after it emerged that the IT glitch meant that hundreds of thousands of final breast screening invitations failed to send.
It is believed that the error could have cut short the lives of up to 250 women.
The newly-established helpline has received over 10,000 calls so far.
Ms Jarvis first noticed how long it had been since her previous screening when she went to her GP to complain about a lump.
"At that stage, I hadn't known about this computer glitch, but I thought obviously I've missed something. It's probably been a year since I should have been tested," she said.
Ms Jarvis's cancer had not spread to her lymph nodes and was successfully removed by mastectomy.
She was then left feeling exasperated that it took more than an hour to get through to the special helpline, where they offered to put her through to Macmillan cancer support.
Asked how she felt about the support offered, she said: "Disappointed. Angry, particularly for the thousands of women affected.
"Also particularly for the families of those who have unfortunately had aggressive breast cancer in these few years that have been missed and have sadly lost their lives. That makes me extremely angry.
"I think there is a major apology needed. There is compensation for those families who have been sadly affected.
"I think they need to get onto it fast - we're all getting older.
"We've all worked, we've paid into the system for many, many years, and they've failed."