In the UK and many other countries, we often hear about the "big four" cancer types: breast, lung, bowel and prostate cancers. Over here, they make up more than half of all the newly-diagnosed cancers every year. But while much attention (and research money) are rightly focused on these diseases, an important group of people are at risk of being neglected - those with rare cancers.
Rare but still too many
In Europe, researchers define a rare cancer as one affecting fewer than six in every 100,000 people in the population. But while only a handful of people may be affected by a specific type of rare cancer in any country, the numbers add up. More than half a million Europeans - and many more around the world - are diagnosed with a rare cancer every year, making up more than one in five of all cancer cases in total. This includes all cancers affecting children.
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This is a big problem, and solving it is hard. For a start, many rare cancers are difficult to diagnose in a timely way. Most family doctors only see a few cases of common types of cancer in their whole career, so the chances of ever seeing a patient with a rare cancer are very small. We already know there can be problems with some doctors and the public failing to be aware of the symptoms of even the most common cancers, so it's not surprising that it can be difficult to spot very rare ones.
Then there are challenges with treatment. Although they all come under the banner of "rare", each type of cancer needs treating in its own specific way. Even in large cancer centres, doctors may only see a few cases of a rare cancer type every year and - depending where they live - it can be hard for patients to get access to specialist experts and treatments. There may be very little certainty even about what the best treatment is, due to a lack of scientific evidence. As a result, people with rare cancers tend to do worse and have poorer chances of survival, on average, than those with more common types.
The problem with research
When it comes to doing research into rare cancers, there are just as many challenges. It's difficult for scientists to get hold of samples of rare tumours, making it hard to do laboratory studies and genetic analysis. There's also a possible reluctance on the part of the pharmaceutical industry to develop treatments for specific rare cancers as the market is so small - although it's likely that new, targeted drugs that work in more common cancers might also have a benefit in rarer tumours. For example, our researchers led trials showing that the leukaemia drug Glivec (imatinib) could effectively treat people with GIST, a rare type of abdominal cancer.
One of the biggest barriers to progress is the number of patients. There just aren't enough people with each individual type of rare cancer in most countries to carry out meaningful clinical trials to find the most effective treatments in a reasonable timescale. In this case, size really does matter - one large trial with many patients should give much clearer, more reliable evidence than several small ones with fewer participants.
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Without the results of clinical trials, it's difficult for doctors to know which approach is best in a given situation. So researchers need to team up to run international clinical trials, recruiting enough handfuls of patients in enough countries to add up to reliable data.
Yet cross-border collaboration can bring even more problems. There may be differences in the 'red tape' governing clinical trials in various countries, as well as problems with international intellectual property rights, contracts and drug supply. And simply organising and co-ordinating trial centres that may be thousands of miles apart can be a logistical nightmare.
Breaking down the barriers
In an attempt to solve this problem, Cancer Research UK has teamed up with the UK NIHR Cancer Research Network, the US National Cancer Institute, and the European Organisation for Research and Treatment of Cancer (EORTC) to create IRCI - the International Rare Cancers Initiative. One of ICRI's main aims is to make it easier for researchers to set up international clinical trials in rare cancers and recruit larger numbers of patients. More trial participants mean better science, more helpful results, and - ultimately - increased survival from these diseases.
The initiative is focusing on cancers affecting fewer than two people per 100,000 including salivary gland cancer, melanoma of the eye and penile cancer to name just a few. And it's trying to encourage more cleverly-designed clinical trials - for example, with multiple groups of patients rather than the traditional two (pdf) - to help get faster and more meaningful results. The researchers involved in IRCI have also stressed the importance of starting to collect tumour samples from people with rare cancers, to fuel further research into understanding these diseases and developing more effective treatments.
At the moment, things are just getting going and trials are being set up and opened. First out of the starting block is a large-scale trial for Uterine Leiomyosarcoma (uLMS) patients (IRCI 001), led by researchers in the US. Two patients have been recruited so far, with nine trials in other rare cancer types in the pipeline.
The road ahead
Although IRCI is a positive move forward to help patients affected by rare cancers, there are still significant issues to be overcome. Contract negotiations across borders are still difficult, and it can be challenging to get researchers from different countries to agree on the best treatments to try out in a trial, based on their own experiences of treating patients. Recruitment onto the first trial, uLMS, has been slower than expected to start with, but it's hoped that this will pick up once it opens in more countries.
On the plus side, there is great enthusiasm from the researchers themselves, who are keen to work together to do something for this under-recognised but significant group of patients. And they're all trying to work together to solve the problems that still remain. Other organisations are starting to come on board, including groups in China, Japan, Korea, Australia, Canada and Russia.
History tells us that, despite the administrative and logistical headaches, working together across borders can bring major benefits to cancer patients. Today in the UK, more than three-quarters of all children diagnosed with cancer will survive, compared to around a quarter in the 1960s, thanks to collaborative clinical trials within and between countries. It would be fantastic to see similar progress being made in rare cancers as a result of everyone, everywhere working together.
Dr Kat Arney is Science Information Manager at Cancer Research UK - the largest charitable funder of cancer research in the world – and writes for the charity's Science Update Blog. Follow Cancer Research UK on Twitter ( @CR_UK ) and on Facebook.
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.