Primary liver cancer originates in the liver. The most common form is hepatocellular carcinoma (HCC).([FOOTNOTE=American Cancer Society. Liver Cancer. Updated April 28, 2016. http://www.cancer.org/acs/groups/cid/documents/webcontent/003114-pdf.pdf Accessed December 21, 2016.],[ANCHOR=],[LINK=]) HCC can start as a single tumor in the liver. It then grows and spreads to other parts of the liver. HCC can also start as many small tumors throughout the liver. When HCC is found only in the liver, it’s called “localized.” HCC can spread outside the liver to the lymph nodes or to other organs in the body. If this happens, the cancer has reached a “regional” or “distant” stage.
The most common risk factors for HCC are hepatitis B, hepatitis C, cirrhosis, nonalcoholic fatty liver disease or exposure to aflatoxins. Long-term hepatitis B or C infections are two of the main causes of HCC1.
Secondary (or metastatic) liver cancer originates in another part of the body and spreads to the liver. In most cases, the metastatic liver tumor grows from cells that have spread from cancer in the colon or rectum.
Cancers in the breast, esophagus, stomach, pancreas, lungs, kidney and skin can also spread to the liver.
Secondary liver cancer is more common than primary liver cancer in the United States and Europe1.
Liver cancer is the 6th most common type of cancer worldwide([FOOTNOTE=Ferlay J, Soerjomataram I, Ervik M, et al. Cancer incidence and mortality worldwide: GLOBOCAN 2012 v1. 0, IARC Cancer Base No. 11. International Agency for Research on Cancer: Lyon, France 2013.],[ANCHOR=PubMed],[LINK=https://www.ncbi.nlm.nih.gov/pubmed/25220842])
While many cancers are on the decline, the incidence of liver cancer is growing by an average rate of 6.5% annually([FOOTNOTE=Rahib et al. (2014). Projecting Cancer Incidence and Deaths to 2030: The Unexpected Burden of Thyroid, Liver, and Pancreas Cancers in the United States. Cancer Res 74(11): 2913-2921.],[ANCHOR=],[LINK=])
Primary liver cancer is the second leading cause of cancer-related deaths worldwide([FOOTNOTE=Benson AB, Abrams TA, Ben-Josef E, et al. Hepatobiliary Cancers: Clinical Practice Guidelines in OncologyTM. Journal of the National Comprehensive Cancer Network: JNCCN. 2009;7(4):350-391.],[ANCHOR=],[LINK=]) ,([FOOTNOTE=World Health Organization, Globocan (2012). Liver Cancer: Estimated Incidence, Mortality and Prevalence Worldwide in 2012. International Agency for Research on Cancer. http://globocan.iarc.fr/old/FactSheets/cancers/liver-new.asp#INCIDENCE1],[ANCHOR=],[LINK=])
In Europe, about 10 in every 1000 men and 2 in every 1000 women will be diagnosed with liver cancer, meaning that it’s 5 times more common in men than in women([FOOTNOTE=Liver Cancer. ESMO/ACF Patient Guide Series, based on the ESMO Clinical Practice Guidelines],[ANCHOR=ESMO],[LINK=https://www.esmo.org/content/download/6615/115103/file/EN-Liver-Cancer-Guide-for-Patients.pdf])