• Question: If you find where the cancer is located, couldn't we just localise the chemotherapy to where it is?

    Asked by griffmeg11 to Clare, Mariana, Pedro, Robert, Susanne on 12 Nov 2012.
    • Photo: Susanne Muekusch

      Susanne Muekusch answered on 12 Nov 2012:

      Hi griffmeg11,
      wow, you are asking good questions today!

      If the tumor was just in one place, it could be removed surgically and the patient would be healed. Unfortunately, cancer tends to spread. This means there are cancer cells that originate from for example colon cancer, but formed small secondary tumors (called metastasis) somwhere else in the body. And that’s where the chemotherapy comes in. It is necessary to administer it to the whole body so it can kill the metasis, too.

      The idea of localised therapy does exist and there are clinical trials for brain cancer to administer drugs directly to the tumor. But I think cemotherapy for brain cancer is still administered via the blood stream, although brain cancers do not metastaise but stay in the brain. I am not entirely sure here- I can look it up, if you are interested? But I would think that the blood is still the best way to reach all the cells- because blood goes everywhere, into every little corner. If you apply something locally, it just might not get very far. The clinical trial I was talking about earlier is based on a substance that is not very stable and would probably never make it to the brain if injected into the blood stream.

    • Photo: Robert Insall

      Robert Insall answered on 12 Nov 2012:

      Susanne gave a good answer.
      Another reason is you can’t give local chemotherapy to some organs. The liver, for example, is so full of blood vessels coming in and out that it isn’t possible to cut into it (you’d never stop bleeding) or put chemotherapy in locally (it washes out). That doesn’t stop people trying – there’s a story in the news recently about restricting the blood flow out of the liver so doctors can treat a liver tumour **fairly** locally.
      Google “liver chemotherapy” and look in the “news” section if you want to see!

    • Photo: Clare Taylor

      Clare Taylor answered on 13 Nov 2012:

      That would be a great idea, but it is difficult to reach some tumours because of where they are located and it is not always possible to deliver the therapy directly to the target. Some therapies have been developed for breast cancer which are more specific than standard chemotherapy, but these are still given to the patient via blood and sometimes that can have an effect on the success of the therapy getting to the right place. This is one of the reasons we are trying to use bacteria in my lab to deliver potential therapies to tumour cells. We know that bacteria like Salmonella prefer tumour tissue to healthy tissue and we are trying to exploit this, first of all to get the therapy to the right place, but then to try and make the therapy only active inside the tumour. There’s lots we need to understand first so it’ll be a while before we can do it for real.

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