Causes of cancer in teenagers and young adults

We don't know what causes most cancers, especially the types of cancer that teenagers and young adults get. When you are a teenager or in your 20s, cancer is something that can just happen without a reason.

Scientists are finding out more about cancer all the time. Understanding the causes of these cancer is an important area of research. In understanding the causes of cancer, we may be able to improve diagnosis, treatment, and ultimately outcomes.

One thing we definitely know is that cancer is not a disease you can catch from someone else - it is not infectious.

Remember that for most cancers:

  • We don't know the cause, and
  • It isn't anything you've done that has caused it.

Risk factors

Risk factors are things that can increase the chances of developing some cancers. Some of them you don't have control over - like genetics, and getting older. Some you do - like smoking, what you eat, drinking alcohol and sunbathing.  

Examples of risk factors:

  • Smoking can damage the DNA in our cells and can eventually lead to cancer.
  • Having too much sun exposure, getting sunburnt and using sunbeds can damage skin cells. This can increase the chances of getting skin cancers like melanoma. 
  • Very rarely, cancer can be caused by a faulty gene that’s passed on through a family (inherited). But this doesn't often happen with the types of cancer young people usually get.

Our information about specific types of cancer has more information about what we know about causes for that type of cancer.