Monday August 20 2012
The number of 'cancer survivors' is expected to rise substantially
One-in-four over-65s 'will have had cancer by 2040', according to the Daily Mail.
The news is based on a study that estimated the number of people living with cancer in the UK by the year 2040.
Figures from 2009 show that around 2 million people in the UK had been diagnosed with cancer and were still alive. These people are referred to as "cancer survivors". By using national cancer statistics and recent population trends for England, the researchers made predictions about how many people they expected to be living with cancer by 2040 and generalised their findings for the UK.
They estimated that the number of UK cancer survivors was projected to rise by about 1 million a decade up to 2040, based on continued trends. They also estimated that the number of over-65s with a cancer diagnosis would rise from 1.3 million in 2010 to 4.1 million in 2040.
This sort of study can provide useful estimates that may help with future health resource planning, but it should be noted that the figures given are only estimates of how many people will have cancer by 2040.
Where did the story come from?
The study was carried out by researchers from King’s College London and University College London and was funded by Macmillan Cancer Support. The study was published online in the peer-reviewed journal British Journal of Cancer.
The research was covered appropriately in the newspapers although all could have emphasised that the study findings are only estimates at this stage.
What kind of research was this?
This was a modelling study that aimed to predict the number of people expected to be living with cancer in the UK by the year 2040. This sort of study can provide useful estimates of the future burden of cancer in the UK. However, it should be noted that these figures are only estimates and alternative modelling assumptions could be used.
The researchers reported no available national prevalence projections for the UK.
What did the research involve?
The researchers looked at specific types of cancer including bowel, lung, prostate and breast cancer as well as all cancers combined (excluding non-melanoma skin cancer). To create their model, the researchers used data from the national cancer registry for England to calculate the number of people living with cancer in 2009. They used cancer diagnoses data from 1971 to 2008 to estimate the number of people living with cancer at the beginning of 2009 and data from the Office for National Statistics for predictions of England population trends. To make their projections, the researchers used two main models with a range of assumptions each:
- The first assumed that existing trends in survival and changing incident rates would continue in the period 2009 to 2040 (dynamic).
- The second assumed current incidence and survival rates would remain constant from the year 2008 all the way to 2040 (static).
They then considered the influence of demographic changes in the population by looking at these different model scenarios based on the above assumptions. Estimations for England were then generalised to the UK.
The researchers hoped that projections from this study would be of use to health service commissioners and resource planners.
What were the basic results?
The researchers have estimated that the number of UK cancer survivors is projected to increase by approximately 1 million a decade from 2010 to 2040 (from 2.1 million to 5.3 million), based on the assumption that existing trends of cancer incidence and survival continue (the first scenario). On the assumption that incidence and survival rates remained constant from 2008 to 2040 (scenario two), the projected number of cancer survivors in the UK is expected to increase from 2.1 million to 3.5 million.
They predicted large increases in the oldest age groups and in the number of long-term cancer survivors, and estimated that by 2040, almost a quarter of people aged at least 65 will be considered “cancer survivors” (23.3% for males and 24.9% for females). When looking at individual cancers, prostate cancer is predicted to increase at the fastest rate for males and lung cancer at the fastest rate for females.
How did the researchers interpret the results?
The researchers concluded that increasing cancer survival and the ageing population in the UK meant that the number of “cancer survivors” is expected to grow substantially in the coming decades, as are the resulting demands on health services. They noted that plans must be made to ensure the needs of cancer survivors can be met by health services.
In discussing the study’s findings, researcher Professor Henrik Møller said: "The research shows that large increases can be expected in the oldest age groups in the coming decades and, with this, an increased demand upon health services."
This sort of study can provide useful projections of the expected number of people set to be living with cancer by 2040. However, it is important to note that the figures are only predictions and have been calculated based on estimates and assumptions. For example, the first model has assumed that future rates of new cancer, improvement in detection rates from screening and improved survival from new treatments will continue past 2009 at the same rate. However, for long-term projections such as this there are many unknowns. For a start, advances in medicine that led to higher survival rates for most types of cancer may not continue in the same way for another 30 years. Furthermore, the introduction of population screening programmes may cause increases in recorded cancer incidence rates and changes to the severity or staging of cancers detected.
The researchers did note that the long-term predictions up to the year 2040, based on the assumption of previous trends, may not be realistic. It will always be relatively uncertain how future medical advancements or the introduction of any new screening might influence the overall number of people surviving or dying by a particular point in time, and in general, it is difficult to make predictions, especially about the future.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on twitter.