• Question: what is the main sorce of cancer

    Asked by capybaras340 to Aina, AlexAgrotis, Alex, Ambre, Anabel, Deepak, Emmanuelle, Ettie, James, Kaitlin, Kate, Vilarino, Marianne, Matthew, MattyB, Nina, Patrick, Rachel, Rebecca, Ross, Ryan, Shobhana, Shonna, Thiloka, David on 11 Jun 2019. This question was also asked by bxbygrace07.
    • Photo: Rebecca Moon

      Rebecca Moon answered on 11 Jun 2019:

      Cancer occurs when there are changes to a cell’s DNA which allow it to replicate in an uncontrolled manner. There are many different types of cancer, which have different risk factors. The best known of these are smoking, which has been linked to more than just lung cancer, and obesity. Exposure to significant amounts of radiation is also a risk factor as radiation damages DNA. This is why people who work with radiation, for example, radiographers, have to be very careful about how much radiation they get exposed to. Some people carry genes which make them more likely to get cancer and they require extra screening to help pick up cancers earlier when they are more easily treated.

    • Photo: Nina Rzechorzek

      Nina Rzechorzek answered on 11 Jun 2019:

      Good question – one of the biggest risk factors is unfortunately something we can’t currently stop – and that’s ageing. This is why more recent estimates suggest that 1 in 2 of us will get some form of cancer during our lifetime, because we are living longer. We are seeing exactly the same trend in non-human animals (i.e. my patients are living longer, so I am seeing more age-related diseases including cancer and canine cognitive dysfunction – which is similar to dementia in humans). There are many lifestyle choices we can make to ‘age better’ or in a more healthy way, but none of these things will completely remove the risk of getting cancer (just lower it). As Rebecca has pointed out, cancer occurs when there are mutations in a cell’s DNA – these mutations occur naturally and by chance over time. Early in life, the cell’s DNA repair machinery is pretty good at correcting these errors, but eventually the efficiency of repair is reduced. Some things such as smoking and radiation cause mutations to happen more frequently and overwhelm the cell’s ability to repair the DNA, which is why these DNA-damaging factors increase the risk of cancer and reduce the age at which it might develop. There is some great information on the Cancer Research UK website about causes of cancer:


    • Photo: Marianne King

      Marianne King answered on 12 Jun 2019:

      I think the main risk factor for cancer is aging, but unfortunately none of us can really do anything about that! In terms of lifestyle choices that we have control over, the main risk factors (according to the Cancer Research UK site) are smoking, low exercise levels, alcohol and being overweight or obese. Risk factors don’t mean that if you do any of these things then you definitely will get cancer, it just means that your chance of getting cancer increases. You can seemingly be the healthiest person in the world and still get cancer. Genetics can play a part as well too.

    • Photo: Kate Timms

      Kate Timms answered on 12 Jun 2019:

      Cancer comes from errors in our DNA called mutations. Often, these mutations occur when a cell is splitting into two new cells. Our DNA is so long and complex, that errors occur when a cell is making a copy of it’s DNA. There are mechanisms in place to stop this, but they don’t always work.
      You can also get mutations from other things like radiation (e.g. from the sun) or from toxins knows as carcinogens (e.g. like the ones in cigarettes).

      When these mutation occurs in in genes which code for proteins involved in things like making more cells, this can cause cancer because the cells can multiply very quickly. Further mutations in genes which make the cells more able to move around can then cause the cancerous cells to migrate to other areas of the body – this is what we call metastasis.

      So really the main source is DNA mutations, but these happen as a result of lots of different things!

    • Photo: Kaitlin Wade

      Kaitlin Wade answered on 12 Jun 2019:

      Others have described the mechanisms by which cancer occurs really well. According to Cancer Research UK and the World Cancer Research Fund UK, smoking is the most dangerous risk factor for cancer alongside obesity.

    • Photo: Matthew Bareford

      Matthew Bareford answered on 14 Jun 2019:

      Cancer is caused by mutations in the DNA of the cells. This is quite often associated with getting older, as you will have replicated much more DNA the older you get, so there is much more chances for things to go wrong. Hence higher chance of cancer.

      In terms of the most common types; in children it is cancer of the blood cells called leukaemia, whereas in adults it is breast cancer in women and prostate cancer in men