By Dr Therese McGlacken, Specialist Registrar in Public Health Medicine, National Screening Service
We provide breast cancer screening for women aged 50 to 69. We’ve invited over 2.7 million women for breast screening and have performed over 2 million mammograms since our BreastCheck programme began. Breast screening aims to find cancer at an early stage before a woman has any symptoms of breast cancer. Over 13,600 cancers have been detected through BreastCheck and screening has contributed to a reduction in breast cancer death rates by an average 1.8% per year.
One in 7 women will be diagnosed with breast cancer in their lifetime. On average there are about 3,365 cases of breast cancer diagnosed in Ireland each year and BreastCheck can detect about one third of all these cases.
Approximately 43% (more than 1 in 3 women) are diagnosed with breast cancer over the age of 70 years. This is because the risk of getting breast cancer, like most other cancers, increases as we all get older. This brings us to a very common question we are often asked. Why doesn’t BreastCheck screen women over the age of 70?
As with any population screening programme, what BreastCheck offers is a one-size-fits all approach for the eligible population, and this means we have to constantly balance the benefits and harms of screening across the entire population of women. One of the harms of breast cancer screening, particularly for women aged 70 and over, is the risk of what is termed ‘overdiagnosis’. This means finding a cancer that may never cause any problems or become life threatening. Another way of looking at it is a type of cancer that you are more likely to die ‘with’ rather than ‘from’.
So, if the scales tips more towards harms than benefits for a particular population or age group, then best practice in cancer screening programmes is clear - we should not proceed with screening. As women get older, overdiagnosis becomes more common and this would put some women through unnecessary anxiety, tests and treatment for a cancer that will not change their life expectancy.
Women in Ireland can be reassured that BreastCheck follows international guidelines for breast cancer screening and in general these guidelines have identified those aged 50 to 69 as the optimal age group for screening. However, evidence does not stand still. We constantly keep these guidelines and international recommendations under review. European Guidelines on breast cancer screening has issued a conditional recommendation to screen women aged 70 to 74 and aged 45 to 49. We have already asked the National Screening Advisory Committee (NSAC) to examine the evidence for extending the BreastCheck programme to women in those age ranges. Before extending the age range, the evidence would need to show that the benefits would outweigh the harms and that it would reduce deaths from breast cancer in Ireland.
Changes to population screening programmes in Ireland, including BreastCheck, must first be evaluated by NSAC. This independent committee makes recommendations to the Minister for Health and the Department of Health. When recommendations are accepted, we begin planning for implementation.
BreastCheck is for women with no symptoms of breast cancer. Whether you are eligible or not for BreastCheck, it’s important to be ‘breast aware’. Most breast cancers (two-thirds) are detected outside of BreastCheck when women present with symptoms to their GP. Get to know how your breasts look and feel at different times. Know the symptoms of breast cancer and if you notice any changes to your breasts, even after a recent BreastCheck screening, talk to your doctor straight away. Don’t wait for your next screening. When breast cancer is found early it can be easier to treat, and there’s a better chance of recovery.