Here’s another of our pieces for Al Jazeera Online, looking at how to tackle rare cancers through international collaborative clinical trials.
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.
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.