Population-based cancer screening is effective - NCRI

Population-based cancer screening has proven to be highly effective in Ireland, a new report from National Cancer Registry Ireland (NCRI) has shown.

The report looked at national cancer trends for breast, cervical and colorectal cancer, all of which have screening programmes in place. It covered the period 1994 to 2019.

BreastCheck began operating in the east of the country in 2000 and was extended nationwide in 2007, CervicalCheck has been in operation since 2008 and BowelScreen since 2012.

The report found that all three cancers showed favourable trends in incidence, stage, survival and/or mortality consistent with improvements in early detection and outcomes. For example, decreases in mortality for all three cancers were generally more substantial in the age groups eligible for screening.

When it comes to BreastCheck, the proportion of women diagnosed with early stage cancers (stages 1 and 2) is higher among those in the screened age group (93%) compared to the non-screened age groups of younger than 50 years (78%) and older than 70 years (75%).

A significant decreasing trend in mortality rates has also been recorded, with an average of 1.8% per annum.

When it comes to CervicalCheck, a significant decreasing trend in rates of the disease of 2.8% per year since 2009 have been recorded. Between 1999 and 2009, there had been a significant increase in rates.

Furthermore, the proportion of cases diagnosed with stage 1 and 2 cancers is much higher in women in the screening age group (88%) than in the non-screening group (52%) and there has been a significant decreasing trend in mortality by an average of 1.1% per year over the 1994-2019 period.

When it comes to BowelScreen, the rates of colorectal cancer in men have shown a significant downward trend of 2.5% per year following the introduction of screening, with a smaller but still decreasing trend (0.3% per year) in women since 1994.

The proportion of cases diagnosed with stage 1 and 2 cancers is much higher in screened men (64%) and women (62%) compared to non-screened age groups of men (37%) and women (39%).

Meanwhile, there has been a significant decreasing trend in mortality over the 1994-2019 period, particularly in the 70+ male age group (3.7% per year since 2011).

“The NCRI report is the first of its kind to analyse the impact of population screening programmes on cancer trends in Ireland. It is agreed that since the 1990s there has been a collective improvement in better awareness of cancer symptoms, new treatments, improvements in care and changes in underlying risks for cancer which have all had a positive impact on improved survival.

“However, with the publication of this report and the detailed analysis of the various screened populations, we can now confidently say that a portion of that improvement is directly attributable to CervicalCheck, BowelScreen and BreastCheck. The public can be reassured that our screening programmes are effective,” commented Fiona Murphy, chief executive of the National Screening Service.

She said she was “particularly struck” by the greater proportion of cancers that were diagnosed early as a result of screening during the 2014-2018 period.

“This is called stage-shift. Finding cancers earlier gives people the best chance of less invasive and aggressive treatments and better outcomes. There is no doubt that screening is an important part of our health service. While the programmes cannot prevent every single cancer, I would urge everyone to register and to take up their invitation to take part when invited,” Ms Murphy added.

The NCRI report on cancer trends can be viewed here.