• Question: why is their mo cure for all cancers?

    Asked by sinvul to Alison, Artem, Caroline, John, Gunther on 19 Jun 2012. This question was also asked by khynaat.
    • Photo: John Short

      John Short answered on 19 Jun 2012:


      Each type of cancer is caused by different mutations, so lung cancer is slightly different to bowel cancer etc. However, even within one type of cancer, such as with breast cancer, the type of mutations that cause this vary from person to person, you can even think of breast cancer having different “strains” like with flu. Even viruses such as Hepatitis B in the liver, and human papilloma virus in the cervix of women can cause or lead to cancer. There may be some commmon enough features for a particular drug in the future to target a subset of cancers, but it would not be able to target all of them I think.

      That is why there is no cure for cancers, as cancers vary in terms of how they are caused and the cellular DNA mutations and between people.

    • Photo: Artem Evdokimov

      Artem Evdokimov answered on 19 Jun 2012:


      Cancers are tough to beat because (1) the cells that become cancerous are *your own cells* (as opposed to bacteria, or viruses – which are foreign and therefore extremely different from you!) and (2) the cause and progression of each type of cancer are quite different; in fact two patients with the ‘same’ cancer (say breast or colon one) can have very different cellular modifications responsible for the disease. Cancerous cells (by definition) have certain unifying features – they are typically defective in mechanisms that control their replication, they can survive in places that their normal equivalents do not survive, and they are able to recruit blood vessels to supply them nutrients. Thus, there is a big difference between a little tumor quietly sitting and doing nothing (most of us have those) and a cancerous growth that sends out cells into the blood stream to colonize other organs (metastatic cancer).

      Curing a cancer would involve either killing off *all* modified cells, or somehow converting them back to ‘normal’ kind. We have the technology to kill off cells, and indeed some cancers can be more or less cured (but the patient later requires a transplant of healthy tissue such as bone marrow because the cure involves killing off entire huge swaths of cells), however this sort of technique is risky and can be dangerous if the patient is weakened. Transforming cancer cells back to normal is the subject of some of the forms of gene therapy but as far as i know there are no reported cures from that area yet.

      In general, I hope that by diligent efforts of doctors and scientists worldwide we can eventually defeat this disease but it is going to take a while!

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