https://publichealthmatters.blog.gov.uk/2017/06/29/the-power-of-data-in-understanding-cancer-survival/

Statistics are important, but some statistics are more important than others!

Statistics are important, but some statistics are more important than others! Today’s release of cancer survival statistics from PHE and the Office for National Statistics is one of the more important ones. 

The data is the work of our two teams and is the latest, most up-to-date and detailed chapter on cancer survival in England.

There is refreshed data on one-year, five-year and ten-year cancer survival in adults and two further new so-called “experimental statistics”, one on cancer survival by stage at diagnosis and the other on cancer survival in children.

Why is this so important?

For many years we have been told that cancer survival in England is not as good as the best places in the world.  Without very good data can we be certain that this really is true?

If it is, can we understand why these differences might exist? And then can we measure whether we are getting better?

Before we can be certain we have cracked this problem, we need to have a measure that is timely, gives a complete picture and helps us to know where to act; one-year cancer survival by stage of diagnosis is that measure.

We need to talk about stage

As a cancer grows, so it spreads – and that spread from the organ where it first starts, to the tissues nearby and then into distant sites through metastasis is measured by the “stage” of the cancer.

Cancer that has spread by the time it is diagnosed– so called late-stage cancer – has a much worse outcome than cancer that is still contained within the organ where it started.

PHE’s cancer screening programmes, our Be Clear on Cancer awareness campaigns and NHS England’s work on faster access to diagnostic tests are all aimed at detecting cancer earlier before it has spread.

By looking at survival and adjusting for the stage at diagnosis we can begin to understand how well we are doing with these interventions, see those cancer types where we are winning and those that need more work.

Behind every piece of data is a patient

Our teams in PHE’s National Cancer Registration and Analysis Service know that behind every piece of data we collect is a patient, their carers and family.

We collect data on all cancer cases, and our registration staff make sure that it is accurate; they also work to get detailed staging data on as many cases as possible.

Last year we had staging data on nearly 235,000 cancers – that is more than 85% of all cases in the top 10 most common cancers.  Our duty is to make sure we have the most accurate, complete data anywhere in the world.

Speed is (nearly) everything

We also want a measure that can tell us as quickly as possible where things are getting better or where we might still have a problem.

Today’s statistics are based on data from all the patients diagnosed in England to the end of 2015.  To calculate one-year survival we then need to wait a year; the earliest we can produce our figures on all patients from 2015 is at the start of 2017.

By working together ONS and PHE have managed to release these statistics up to eight months earlier than previously and we are confident that in future we will be even quicker so we can begin to see as soon as possible whether we are making progress.

What do the figures tell us?

For adults, one-year survival is highest in malignant melanoma in men (97%) and women (99%) and is lowest in pancreatic cancer in men (23%) and women (25%).

Five-year survival is highest in cancer of the testis (96%) and malignant melanoma in women (94%) and is lowest in mesothelioma (a cancer of the lining of the lungs) for men (6%) and women (3%).

The one-year survival in patients diagnosed with early-stage disease (stage 1) is greater for breast cancer in women, melanoma in both men and women and for prostate cancer.

In fact, survival in these cancers, when they are found early, is now so good that there is no noticeable reduction in survival in those who have had cancer compared to general population.

Unfortunately, this is still not the case for all early stage cancers: early stage lung cancer has the lowest one-year survival at 86% in men and 90% in women.

For patients diagnosed when the cancer has spread to other parts of the body (stage 4), one-year survival is lowest for lung cancer (17% men, 22% women) and highest for breast cancer in women (66%) and prostate (88%) cancer.

Childhood cancer survival has also improved since 1990.  Children under 15 diagnosed with cancer in 1990 had a five-year survival of 67%; our prediction is that for children diagnosed in 2016 it will be 85%, with similar increases in one- and ten-year survival.

What next?

So, England has some of the best cancer data in the world.  What we need to know now, is how do we compare with the most recent and up-to-date, accurately staged, cancer data from other countries?

To find out we are working with the International Cancer Benchmarking Partnership and PHE has joined the Union of International Cancer Control so that we can learn from others and share our own work with the rest of the world.

But whatever the international comparative data shows there is no question that we cannot be complacent.

We must do more to diagnose cancer earlier, increase the participation for our cancer screening programs and make sure that anyone who has possible symptoms of cancer goes to see their doctor promptly.

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