Here is a timeline of high-profile failures and delays in the diagnosis of cancer patients:
June 2006: Rebecca O'Malley undergoes a mastectomy in London after a 14-month delay in her cancer diagnosis. The mother of three was misdiagnosed after a biopsy taken at the Midwestern Regional Hospital, Limerick, was tested at a Cork University Hospital laboratory.
August 2007: Breast cancer services are suspended at the private Barringtons Hospital in Limerick and a review launched after the Health Information and Quality Authority (Hiqa) raises concerns about the management and care of 10 women who attended breast disease services since 2003.
November 2007: A review of cancer checks in the Midlands Regional Hospital in Portlaoise reveals 97 women face new tests despite being given the all-clear. Nine women falsely given the all-clear after mammograms later learned they had breast cancer.
September 2008: An independent inquiry begins into services at Ennis General Hospital for allegedly failing to diagnose breast cancer in the cases of two women - Edel Kelly (26), and Ann Moriarty (53).
November 2008: Health chiefs reveal nine lung cancer patients received delayed diagnosis after being given the all-clear following tests at Our Lady's Hospital Navan and Our Lady of Lourdes in Drogheda.
April 2009: A GP raised concerns with Hiqa complaining of a backlog of radiology reporting at Tallaght Hospital. The watchdog met then chief executive Michael Lyons and current chief executive Professor Kevin Conlon and asked for urgent updates on clearing the backlog.
January 2010: Tallaght chiefs admit the scale of the crisis with 58,000 X-rays not reviewed by consultant radiologists from 2005.
March 2010: The hospital says two patients - one of whom later died and another who is undergoing cancer treatment - had their diagnoses delayed as a result of the build-up.