At Cancer Research UK, we regularly get asked why we spend different amounts on different types of cancer.
Most commonly, people want to know why we spend more on breast cancer than on prostate cancer, despite the fact that there are similar numbers of cases of each per year.
These queries often contain the accusation, implied or explicit, that there is some prejudice against men, or male cancers, amongst the cancer research community.
This is absolutely not the case. Although there has been a deficit in prostate cancer funding in the past, there’s been a substantial effort to remedy this, and with the creation of organisations like the Prostate Cancer Charter for Action, we’re now seeing some focused, concerted action on this front.
But nevertheless, there’s still a discrepancy in the research spend. And ultimately, this has much more to do with the science and biology of prostate cancer than the politics of research funding.
The simple fact is, we know much, much less about prostate cancer than we do about any other cancer in the ‘big four’ (i.e. lung, breast, bowel and prostate cancer, which account for nearly 45 per cent of all cancers diagnosed in the UK).
“But surely,” you ask, “if you don’t know much about prostate cancer then you should spend more money on finding out?”
Sadly, its not quite that simple.
The causes of cancer
As we know now, cancer occurs when ‘things in the environment’ interact with our genes. Some people get dealt a ‘bad genetic hand’ – they inherit genes from their parents that make them more susceptible to the effects of these environmental factors.
So understanding the causes of cancer means working out two things: the genes involved, and the identity of these mysterious ‘things in the environment’. As Ed wrote about last week, gene-environment interactions are the key to understanding cancer.
Breast cancer & hormones
In the case of breast cancer, we’re pretty advanced in our understanding. We know that the ‘environmental factors’ are, essentially, variations in woman’s hormone levels caused by pregnancy, menopause, the Pill, HRT etc.
And we know about many of the genes involved, what they do, and how they can go wrong.
So its relatively easy to carry out research on breast cancer. We know a lot about it, so scientists can ask lots of sensible questions and carry out lots of research into different aspects of the disease.
Bowel cancer & diet
Bowel cancer, as you might expect, is linked to diet. What you eat has an effect on how your bowel cells grow and divide. The disease appears less common among people who eat a lot of fibre, and more common among people who eat a lot of red and processed meat. Alcohol too seems to be linked to higher rates. And exercise helps, possibly by working any nasties out of your system quickly.
Genetically speaking, however, we’re still feeling our way. We know a fair bit about a few of the genes involved, and how gut cells can develop into polyps, and then into cancer cells. But there’s still a long way to go.
Lung cancer & smoking
With lung cancer it’s even more simple. Smoking is so horrifically damaging to your DNA that you don’t even need ‘bad genes’ – nine-out-of ten lung cancers are caused by smoking. Interestingly, as smoking rates fall, we’re starting to find out more about the genetics of the disease, but that’s a story for another day. Given the starkness and strength of this one single environmental risk factor, its unsurprising that millions have been spent on anti-smoking strategies.
Prostate cancer & …?
But with prostate cancer, we’re much less advanced in our understanding.
We know there’s definitely an environmental effect, because rates are rising in the West and vary from country to country. There are suggestions that bodyweight, for example, can affect the risk of aggressive forms of the disease.
And we know there’s a genetic component because it can run in families, because different ethnicities have different rates of the disease, and because different men get different ‘types’ of prostate cancer.
But beyond that, we don’t know an awful lot for sure. And as a result, we still don’t really know the best way to treat men with prostate cancer, or who best to offer PSA screening. And ultimately, its difficult to push forward with the sort of research effort we see in breast cancer, when we know so little.
The way forward
But things are changing. Last week saw the publication of three papers in Nature Genetics that look set to kick-start prostate cancer research. The papers reported the discovery of a whole host of new genetic markers for the disease. One the papers reported the first results from a huge 13-year £multi-million gene-hunting study led by Cancer Research UK-funded scientists Ros Eeles and Doug Easton. The other two papers reported similar results from groups in Iceland and the US.
Taken together, these papers represent a huge step forward. Now we can, for example, start looking at the lifestyles of men who have several of these markers – that ‘bad hand’ we mentioned earlier – see which of them get cancer and which don’t. This should in turn allow us to pinpoint the environmental factors that affect cancer risk.
These findings also allow us to look at which markers are linked to aggressive cancers. We can think about offering screening to men whose markers tell us they’re at high risk. We have a starting point to develop new drugs. We can even, potentially, find out which men to exclude from testing, saving men from unnecessary worry, and saving vital healthcare resources.
In short, we’ve found some key pieces of the jigsaw puzzle, and now some of the other bits should start falling into place.
These findings won’t – yet – have any direct consequence for men who currently have prostate cancer. But as a result of these discoveries, hopefully the future will be a brighter place for prostate cancer research and, ultimately, for men diagnosed with the disease.
Chris June 24, 2009
It sounds as though we are only getting out of the starters blocks in the race to find a cure for prostate cancer. While I take the point that as we know less then there is less spending on research that can be done, why is it so far behind breast cancer understanding in the first place?
I think your comment “there has been a deficit in prostate cancer funding in the past” sums it up. Which to me IS prejudice considering the number of men affected by it.
Henry Scowcroft July 25, 2008
That’s a really good point, Aoife – and I suppose you could draw the conclusion from the post that research into lung cancer biology isn’t a priority for us – which is emphatically not the case! We’ve actually increased our spending on lung cancer massively over the past few years, since the NCRI called for more lung cancer funding.
There’s info on our lung cancer research portfolio on our main website, if you want to know more…
Aoife Regan July 25, 2008
Hello Henry great article – very informative. I have one slight quibble though. You say that we know much less about prostate cancer than we do about the other big four. It is true that we know much less about the cause of PC, but when you look at the basic biology, natural history, genetic disposition, early detection and diagnosis and treatment etc it could be argued that we know more about PC than we do about lung cancer. Only about 1/7 life-long smokers get lung cancer, but we can’t yet identify those at greatest risk. 10-20% of lung cancer cases are in non-smokers, accounting for between 3.5 and 7k deaths every year, we can only guess at what causes this cancer. Due to the inaccessibility of the lungs for tissue sampling we have only very patchy information on the natural history of the disease. Surgery is the only treatment that can offer a cure and this only for the most early stage patients. Unlike prostate cancer, available treatments offer survival advantages in months not years and the spend on prostate cancer research is almost double that of lung cancer. Whilst vitally important and with respect there is more to tackling lung cancer than tobacco control