The Irish Cancer Society has warned of a significant backlog in cancer screening and treatment services.
Addressing the Oireachtas Health Committee this morning, CEO Averil Power told politicians that the health service is under "intolerable strain" due to the pandemic and the recent cyber attack on the HSE.
Ms Power warned that the cyber attack was "crippling a system that was already on its knees".
She said some Rapid Access Clinics have indicated that the IT attack has had a much worse impact on their services than Covid-19.
During the same committee hearing, the Irish Medical Organisation warned that the recent cyber attack has "further compounded delays with radiotherapy and screening appointments having to be postponed or rescheduled".
Regarding the impact of Covid-19, Ms Power said it is too early to say how many pre-cancers and cancers have gone undetected due to the pandemic.
However, she pointed out that "Breastcheck was 70% behind its 2020 target of completed screenings, BowelScreen was 60% behind target and CervicalCheck was 44% behind target".
Meanwhile, figures sent to NPHET by the National Cancer Control Programme show that the number of patients receiving chemotherapy last year was at 70% of 2019 levels, while radiotherapy patients were at 80% for the same period.
Ms Power told TDs and senators that undetected cancers are "hiding underneath the chaos that Covid has visited on our overwhelmed healthcare system".
She appealed to politicians to prepare for a surge in more advanced cases of cancer in the coming months and years.
The Irish Cancer Society would like to see Government adopt the Individual Health Identifier across cancer services and improve data services to improve real-time information on cancer services.
The committee also heard from the Irish Hospital Consultants Association.
It appealed for one in five hospital consultant posts, that are currently vacant, to be filled in order to clear the "huge backlog and other service delivery constraints".
IHCA told the committee that 883,000 people are on some form of a National Treatment Purchase Fund waiting list.