22/11/2011 05:00 GMT | Updated 21/01/2012 05:12 GMT

The Great Cancer Survival Lottery

New cancer statistics often make the headlines. Politicians use them consistently to either berate or praise the NHS. We compare ourselves against our European neighbours with them, and we seem to have an unending appetite for crunching numbers to contextualise this disease that so many people fear.

But what do all these stats actually tell the patients who are going through cancer?

Today Macmillan has released more cancer survival statistics - but this time we've calculated the median survival time for the top 20 cancers over the last 40 years.

This is hugely important because for the first time we can better discuss that crucial question every patient wants to know when they are told they have cancer - how long have I got to live?

There is no straightforward answer to this for an individual patient, but median survival must shape how the issue is discussed.

Cancer survival is usually presented by counting the number of people to reach certain milestones; one, five or 10 years after diagnosis.

But this doesn't always show big, proportional increases in the number of people reaching a particular milestone. It can still mean there has been little actual improvement in the average survival time. Median survival time is the time since diagnosis when relative survival is at 50% and we interpret this as the time when half of the patients have survived (or half have died).

So first the good news. People diagnosed with breast, colon, cervix, Hodgkin's, larynx, melanoma, testes or uterus cancer have a prognosis of 10 years or more. That is fabulous progress.

Colon cancer in particular has seen the biggest improvement with median survival increasing from around seven months to 10 years. For these patients, cancer may be more akin to a long-term chronic illness, rather than something they will die of.

But for people who are diagnosed with brain, pancreatic or lung cancer, the median survival time has barely changed since 1970. Shockingly, these cancers continue to have a prognosis of mere months. Lung and brain cancer median survival times have scarcely risen, from 11 to 20 weeks; and from 13 to 28 weeks respectively. Pancreatic cancer has the lowest median survival time and has seen practically no progress. Survival has increased by just three weeks (from nine to 12 weeks).

So why is there such a huge gap in prognosis between these cancers? We know there has been great work on breast cancer treatments and this has had a clear impact on breast cancer survival.

Research into breast cancer accounted for 20% of site-specific research funding in 2010, more than the combined spend on some of the cancers with the lowest median survival times - stomach, oesophagus, pancreas, brain and lung - which made up 13% of site-specific research funding in 2010.

It is clear that much, much more money needs to be put into surgery and treatment options for the cancers with the poorest prognosis.

Macmillan's research also has a huge impact on how the medical profession should be treating cancer patients. For a doctor sitting opposite a patient, it has real implications for the conversation they have with their patients and the information they give them.

So, for example, a breast or colon cancer patient is in reality often living with a long-term chronic disease and should be given information on the long-term effects of their treatment. A doctor talking to a lung or brain cancer patient, however, needs to give more information on supportive care, palliative care and life extending care.

While it is fantastic news that more cancer patients are living longer overall, our research also shows that they are not necessarily living well. Cancer treatment is the toughest fight many will ever face and patients are often left with long-term health and emotional problems long after their treatment has ended.

They are left struggling to cope with the effects of their treatment, effects such as heart disease, early menopause or chronic fatigue. The NHS really needs to recognise cancer's long-term impact on people's lives, to plan better services and to develop more personalised care.

Our research does help us address better the question every cancer patient wants to know about how long they have left to live. But it also throws up other questions such as why do some cancers have a prognosis of years, even decades but others are still hovering at a few months or even weeks? What is being done to address this and are the right research priorities getting the right funding?

At least as urgent is ensuring the NHS across the UK starts to recognise cancer's long-term impact on people's lives and to plan better long term services that really fit the modern needs of cancer patients.

For more details Macmillan's research briefing paper Living After Diagnosis - Median Cancer Survival Times is available here.