A metastasis starts when cancer cells break away from the original (primary) tumour, travel through the blood or lymph system, and form a new tumour in other organs or tissues of the body. Liver metastases is the spread of cancer cells from the place where they first formed to the liver.
Liver metastases from bowel cancer
The colon is the part of your digestive system where waste material is formed. The rectum is the end of the colon which attaches to the anus. Together, the colon and rectum form the large intestine, also called the large bowel.
Bowel cancer is the fourth biggest cancer killer in the world, following lung, liver and stomach cancers respectively.
The frequency of colorectal cancer varies around the world. It is common in the Western world and is rare in Asia and Africa. In countries where the population has adopted western diets, the incidence of colorectal cancer is increasing.
Cancer cells of the colon and rectum can invade and damage adjacent tissues and organs (local spread). Cancer cells can also break away and spread to other parts of the body such as the liver and lungs.
Blood from the bowel flows directly to the liver. This means the liver is a common place for bowel cancer to spread to.
Colorectal cancer typically spreads to the liver before it spreads to other sites. Cancer has already spread to the liver in about 25% of people who are diagnosed with colorectal cancer. Liver metastases are also likely to develop over time in another 25-30% of people with colorectal cancer.
However, metastases from bowel cancer are often present already in the liver before spreading to other sites. Thus, treatment directed at the liver can be very valuable and make a huge difference for many patients even though in most situations a cure cannot be achieved.
Symptoms of liver metastases from bowel cancer
Often liver metastases from bowel cancer, like in primary liver cancer do not cause any symptoms for a long period of time. If symptoms do occur, they may include:
- Pain over the top right of the abdominal area
- Unexplained weight loss
- Weakness or tiredness
- A hard lump under the ribs on the right side of the body, which could be the tumour or a sign that the liver has gotten bigger
- Lack of appetite at a late stage, yellowing of the eyes and skin (jaundice) and abdominal swelling (ascites)
Liver metastases from other types of cancers
Many other cancers can spread to the liver such as breast cancer, neuroendocrine tumours, pancreatic cancer, etc.
Ferlay J et al. Global Cancer Observatory: Cancer Today. Lyon, France: International Agency for Research on Cancer; 2018. Available from: https://gco.iarc.fr/today, accessed on 01 December 2018.
Clark ME et al. J Gastrointest Oncol 2014; 5: 374–87.