Metastases is a word that is commonly associated with cancer patients. It simply means that the cancer has spread to nearby or distant organs.
Cancers have a unique ability to spread from a primary site, and the liver is one of the most common organs where cancer tends to spread to early on. Once the cancer has spread to the liver, it is known as liver metastases.
Getting a diagnosis of liver metastases can be daunting. The following sections briefly outline the key early symptoms to look out for, the contributing factors, different routes of liver metastases, as well as the treatment options available for liver metastases.
Cancer can spread from a primary site, and the liver is the most common organ that cancer spreads to. Liver metastases account for almost 25% of metastasised cancers.1 The cancers that most commonly spread to the liver are colorectal cancers followed by breast cancers, lung cancers and pancreatic cancers.
Causes of liver metastases
The body is comprised of a network of vessels that connect each and every organ together. Cancer cells often break away and travel through these vessels from a primary cancer site to the liver. For example, cancer cells from colorectal cancer are commonly spread through blood vessels (which carry oxygen and nutrients via the blood) and can cause liver metastases. However, some cancers, such as breast cancer, have the ability to spread through the lymphatic vessels (which carry excess fluid).2 Liver metastases are caused by primary cancers that spread to the liver. The cancers that are prone to cause liver metastasis are:
- Colorectal cancers
- Breast cancers
- Lung cancers
- Stomach cancers
- Pancreatic cancers
- Ovarian cancers
Signs and symptoms of liver metastases
Common signs and symptoms are:
- Abdominal discomfort
- Pain on the right side of the abdomen
- Unintentional weight loss and loss of appetite
- Full and distended abdomen
- Lethargy and feeling nauseous
- Uncontrollable hiccups
- Yellowish skin and eyes
- Generalised itchiness on the whole body
Management and treatment for liver metastases
Treatment and management of liver metastases largely depend on the origin of the cancer. Primary liver cancers have a different protocol of management. In the case of liver metastases, also known as secondary liver cancers, the primary cancer is usually a target for therapy as well.
Treatment options can be medical and surgical depending on the extent of the metastasis.
Surgically, hepatic resection, which means surgically removing the affected part of the liver, is considered to be the first line of management. Given that liver cells have the unique ability to regenerate, this option is often preferred if the patient is fit for surgery.
Medically, certain treatment options are also available, depending on the primary tumour. They can be:
- Chemotherapy regimens: Certain chemotherapeutic agents such as oxaliplatin and irinotecan which target the cancerous liver cells or tumours are often used2
- Monoclonal Antibodies: These are very precisely targeted therapies, which directly act on the cellular mechanism that causes the cancer. Tyrosine Kinase Inhibitors (TKIs), a class of monoclonal antibodies, are used generally in liver metastases where the primary cancer is of gastrointestinal origin2
- Ablation and cryotherapy techniques: Both radio frequency and microwave ablation techniques focus on using waves or frequencies which can increase the temperature in the cancer cells within the liver. This in turn kills the cancer cells in the liver. Like heat, freezing techniques, such as cryotherapy, are also used to treat liver metastases
- Radio-embolisation: Radioactive material such as Yttrium-90 can be used to kill cancer cells via delivery to the cancer site in the liver
Medical and surgical treatment may have to be used together to ensure the prevention of further spread and effective elimination. This largely depends on the type of primary site tumour and the extent of spread.
Diagnosis of liver metastases
Diagnosing liver metastases is generally done by imaging techniques. Cancer patients who attend regular follow-ups often undergo imaging tests. These include:
- CT scan
- MRI scan
- PET scan
- PET-CT scan
Patients who develop symptoms of liver metastases also undergo these imaging techniques. Certain blood test markers, such as abnormal liver enzymes, can also warrant imaging techniques to be scheduled by the doctor.
Unlike primary liver cancers, where certain dietary habits such as increased alcohol intake, or viruses such as hepatitis, play a role in the development of cancer, liver metastases occur exclusively as a consequence of the primary cancer, such as colorectal cancer or breast cancer, spreading to the liver from the primary site.
- Possible complications of liver metastases include:
- Organ failure: Particularly in extensive spread, liver failure is the most common complication of liver metastases
- Poor health, decreased appetite, and bile duct blockage which results in the inability to metabolise fat
- Swollen abdomen and, in the later stages, swollen limbs, commonly known as oedema
Can liver metastases be prevented?
Liver metastases can be prevented. By virtue of early detection of the primary cancer and initiation of treatment, complications such as liver metastases can be largely avoided. It is important to remember that liver metastases can occur even after successful primary cancer treatment. Hence, regular follow-ups to the clinic are necessary.
How common are liver metastases?
Liver metastases make up 25% of metastasised cancers and the liver is, therefore, the most common site for cancer to spread to.1
When should I see a doctor?
Any cancer patient who has been diagnosed or is receiving treatment, as well as those that have completed their treatment successfully, should be mindful of the symptoms listed above, particularly discomfort in their abdomen and loss of appetite. Patients should seek medical advice immediately if they notice any unintentional weight loss, pain, or loss of appetite.
One of the most unique characteristics of cancers is their ability to spread to other organs, which is called metastasis. The liver is one of the most common sites for this spread. A diagnosis of liver metastasis can be daunting. However, metastisis can be avoided by early treatment and regular follow-ups. Considering the availability of the emerging treatments, even after being diagnosed with liver metastases, symptoms can be managed medically as well as surgically. Cancer patients should educate themselves on the early signs of liver metastases, attend their regular follow-up appointments (even after the successful treatment of the primary cancer), and in the case of a diagnosis, discuss available options with their oncologist.
- Abbruzzese JL, Abbruzzese MC, Lenzi R, Hess KR, Raber MN. Analysis of a diagnostic strategy for patients with suspected tumors of unknown origin. J Clin Oncol. 1995 Aug;13(8):2094-103. Available from: https://pubmed.ncbi.nlm.nih.gov/7636553/
- Tokisawa H, Aruga T, Kumaki Y, Iwamoto N, Yonekura R, Ishiba T, Honda Y, Suzuki M. Metastasis of breast cancer to liver through direct lymphatic drainage: a case report. Journal of International Medical Research. 2021 Dec;49(12):03000605211064793. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8721733/