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Macmillan and Cancerbackup merged in 2008. Together we provide free, high quality information for people affected by cancer through our publications, website and phone service. Find out more|.
Find out how we produce our information|
Although surgery for many cancers will cure the cancer, it's not always possible to know at the time of surgery whether the cancer is definitely cured.
The surgeon removes the tumour and a surrounding area (margin) of normal tissue. Although the scans may look clear, cells could have broken away from the main tumour and spread to another part of the body before the surgery. These early secondary cancers, called micro-metastases, may be too small to see on a scan. It is because of the potential risk of micro-metastases that other treatments, such as chemotherapy| and radiotherapy|, are sometimes given before or after surgery.
Sometimes a surgeon will find during an operation that a cancer can't be completely removed. Scans don't always give the full picture, and surgeons will not always know the extent of the cancer until they operate.
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.