Less common and rare cancers
We don’t just focus on the ‘big four’ of cancer – prostate, colon, breast and lung. We also investigate new treatment options for less common and rare cancers.
What is ‘less common’ and how rare is ‘rare’?
A cancer is rare if fewer than 6 in 100,000 people are diagnosed annually, and a less common cancer is defined as one occurring between 6 and 12 times annually per 100,000 people. In Europe, 1 in 5 people diagnosed with cancer have a rare type.

Every cancer deserves the same attention
Often, the cancers occurring most often get the most attention – and the most research money. The pharmaceutical industry invests more resources in the most common cancer types due to the larger return on investment. In addition, treatment options for rare cancers are often more limited and less effective than those for common cancers. This is partly because there is less clinical research and fewer clinical trials for rare cancers, as it is harder to enroll enough people for a study. The ACF believes that less common and rare cancers deserve as much attention as more common types.
Less common means additional challenges
Any diagnosis is difficult, but rare cancers can be especially challenging for patients, their caregivers, and even clinicians. Rare cancers are more difficult to diagnose than common cancers, and are thus more likely to be diagnosed at later stages, making them harder to treat. Lack of clinical expertise might lead to incorrect diagnoses, delaying access to the appropriate treatment. Results are limited, making it more challenging for patients and their relatives to find the right information and support.
For many rare cancers, research to identify causes or develop strategies for prevention or early detection is also extremely difficult.
A rare cancer might...
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be a subtype of a more common cancer;
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start in different types of cells than common cancers do;
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be in an unusual part of the body for that type of cancer;
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affect a child or young adult (almost all cancers in children and young adults are considered rare).

Rare cancers in children
Rare cancers occur most often in children and young adults. 71% of cancer types diagnosed in children under 20 years old are rare cancers. Although the 5-year survival rate is higher for children than for adults with rare cancers, all patients with rare cancers have poorer survival than those with common cancers. Because therapies for these children are limited, we strive to offer them additional treatment options by investing in paediatric clinical trials.
Our trials in this focus area
- Solid tumours
- Paediatric cancer
- Paediatric cancer
- Brain cancer
- Solid tumours
- Bone cancer
Onze focus
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Drug repurposing
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Minder vaak voorkomende en zeldzame kankers
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Combinatietherapieën
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Herval voorkomen
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