• Question: Why does cancer come back after remission?

    Asked by anon-328802 on 9 Jun 2022.
    • Photo: Karin Purshouse

      Karin Purshouse answered on 9 Jun 2022:

      Cancer can come back after unfortunately, and we sometimes give patients treatment like chemotherapy or radiotherapy after they have had a cancer removed to reduce the risk of it coming back (we call this ‘adjuvant therapy’). That’s because sometimes there are cancer cells that no scan or operation can see (And therefore we can’t remove by an operation), and sometimes these cells can go to other organs in the body in a way that can’t be seen on a scan or cause symptoms until they have grown. I hope that answers your question?

    • Photo: Rachel Harris

      Rachel Harris answered on 10 Jun 2022:

      When there are so few cancer cells that we can’t detect them, we say the patient is in “remission”. Unfortunately there’s no scan or test yet that would be precise enough to detect extremely low levels of cancer cells, so this is why we usually say they’re “in remission” and not “cured”. If those few cells are viable, they can start to grow again once the treatment is removed, which is why it’s important for patients in remission to go back and get checked.

    • Photo: Chelsea Gerada

      Chelsea Gerada answered on 13 Jun 2022:

      You can imagine cancer cells in a tumour being like a jar of marbles. Different therapies might get rid of a particular colour of marble e.g. chemo gets rid of red marbles but you are still left with yellow, green and blue marbles. Because there is so much diversity within one tumour it is difficult to eliminate all the cells. Even if a small percentage of cells remain after therapy they can eventually grow to reform the cancer.

    • Photo: Maria Peiris Pages

      Maria Peiris Pages answered on 13 Jun 2022:

      That is a great question Rowan! Unfortunately sometimes a few cells (not enough to be detected by regular detection methods) can survive treatment or remain after surgery. These cells can then eventually re-start growing another tumour. There is also the metastasis problem. It can happen that you cure the primary tumour but there are at that point some cells that have traveled somewhere else in the body (metastatic cells). These can stay quiet for a while (quiescent or dormant) but sometimes they wake up and grow tumours as well (metastases)

Comments