(tumours that have spread to the liver from other sites)
What are liver metastases?
Liver metastases (secondaries) are lumps in the liver that have spread via the blood stream from the original site (primary) of another cancer (e.g. colon or pancreas). The tumours are different to the liver tissue and contain cells of the original tumour. These tumours have already spread from other sites, so they are more advanced and could have spread to other sites apart from the liver.
What tumours spread to the liver?
Any cancerous tumour has the possibility of spreading to the liver, but it most commonly occurs from the digestive organs (colon, rectum, stomach, pancreas and oesophagus). Neuroendocrine tumours (from hormone producing cells) also commonly spread to the liver. Less commonly renal cancers, breast cancer, blood cancers, sarcoma, melanoma and gynaecological cancers may spread to the liver.
Liver surgery for is most commonly performed for colon and rectal cancer liver metastases. Neuroendocrine liver metastases are also often removed. Tumours which have spread to the liver from other sites are sometimes removed and they are grouped as “non-colorectal non-endocrine liver metastases”. This is performed on a case by case basis as the results from surgery are highly variable.
What are the symptoms?
Often liver metastases are found as part of follow up for other cancers after treatment, but often they are found to be present when the original cancer (primary) is diagnosed
Surely it’s much harder to treat a cancer that has already spread via the blood?
An analogy for the treatment of cancer that has spread is like a grass lawn with a weed.
“If you notice a single weed in the garden you pull it out (this is surgery to a primary cancer) and make sure there are no other weeds (cancer staging). It may be worth applying weedkiller (chemotherapy) to stop further weeds, but this may cause damage to the healthy grass as well.”
“The weed comes back the following year at multiple sites, as the weed must have germinated prior to being pulled, or the weeds were so small they couldn’t be seen last year. Now you have a bigger problem, weedkiller alone can’t kill the larger weeds, unless you apply so much as to kill the whole lawn. In this situation, only a thorough search for all weeds, pulling them out with the roots intact and then applying weedkiller will be successful”
What tests are performed for liver metastases?
A thorough search for all sites of spread is performed and this is called ‘cancer staging’. This may include:
- Blood tests called tumour markers
- CT scan of the chest and abdomen and the primary site of cancer
- MRI scan of the liver
- PET scan of the whole body
How are liver metastases treated?
Liver metastases are treated by groups of doctors who participate in specialist multi-disciplinary teams. Liver surgery forms the basis of treatment, when all the metastases can be removed. Surgery is often combined with chemotherapy to reduce the risk of them coming back.
Other treatments include radiotherapy (whole liver, stereotactic or radiation spheres) ablation (microwave, radio wave or Nanoknife®) and blocking the blood supply to tumours (embolization).
What is the prognosis of liver metastases?
With the combination of surgery and chemotherapy survival from colorectal liver metastasis can be 50% (at 5 years). This is influenced by many factors including the size and number of metastases, whether they were present when the primary was found, whether lymph nodes were involved and whether there was spread outside the liver.
Liver resection for neuroendocrine tumours, if feasible, can be associated with long term survival and symptoms relief.
For other liver metastases (NCNELM) long term survival can be achieved in a small highly selected group of patients.