Metastatic liver disease is the most common cause of death in cancer patients. Complete surgical resection is currently considered the only curative treatment, with only about 25% of patients being amenable to surgery.
Lymph nodes are the most common site for metastatic malignant spread with the liver next in frequency. The vulnerability of the liver for metastatic disease may be related to the fact that it is the largest organ in the body and it filters blood from both the systemic and portal systems. Humoral factors promoting cell growth and blood flow are second only to the lungs.
Most liver metastases are multiple and affect both lobes. Single metastases occur in only a minority of patients. The most common primary sites for hepatic metastases are colorectal, stomach, pancreas, breast, lung and eye. In children, the most common primaries are neuroblastoma, Wilm's tumour and leukaemia. Most tumours that have spread to the liver have metastasised to other sites as well.
- Hepatomegaly and ascites are present in about half of patients with liver metastases. Nodularity may be palpable along the enlarged liver edge. Ascites indicates wide dissemination and a poor prognosis.
- Large metastases may block bile ducts and cause jaundice, malaise, anorexia and loss of weight.
- Abnormal blood results may include anaemia and leukocytosis. Bilirubin, alkaline phosphatase and transaminase levels may be raised but LFTs are not always abnormal.
- A number of tumour markers have been identified, including alpha-fetoprotein (AFP), protein induced by vitamin K absence (PIVKA-II), carcinoembryonic antigen (CEA) and CA19-9 but their diagnostic accuracy needs further evaluation.
- CXRs and abdominal ultrasound may be helpful; plain abdominal X-rays less so.
- Ultrasound (especially when enhanced with Doppler or colour-flow imaging). CT, MRI and positron emission tomography (PET) scanning may all be useful in varying circumstances.
- Angiography is essential if vascular intervention is planned.
- Biopsy is needed for an histological diagnosis. However, biopsy can lead to needle tract metastases and some argue that in Western populations where primary liver tumours are rare, investigation should focus on finding a primary source when investigating malignant liver lesions.Liver biopsy is not advised if the tumour is operable.
Treatment for metastatic liver cancer depends on the location and stage of the cancer and how well liver function is preserved. Treatment options include surgical resection, thermal ablation, systemic chemotherapy, transarterial chemoembolisation and selective internal radiation therapy. Liver transplantation may be appropriate for some patients. For most patients with liver metastases, treatment with curative intent is not possible.
Hepatectomy for stage IV colorectal cancer is considered the standard of care for resectable isolated hepatic disease and acceptable performance status. However, the indications for resection of non-colorectal origin liver metastases are not as clearly defined.[4, 5]
Partial hepatectomy to remove a single deposit may prolong survival. Patients must be carefully selected and be free from extrahepatic metastases.
Recent but limited outcomes data on liver transplantation for unresectable hepatic metastases from colorectal cancer have claimed some survival benefit compared to the previous reports. However, there is a high rate of tumour recurrence within a very short time after liver transplantation.[6, 7]
- Minimally invasive treatments, including freezing, ethanol and lasers, have also been used in the treatment of metastatic hepatic deposits. Radiofrequency ablation is a popular technique.[8, 9]However, more trials are needed to look at its effectiveness.
- Transcatheter arterial chemoembolisation (TACE) can block the blood supply to hepatic tumours, and microcatheters can be used to deliver chemotherapeutic agents.
- The National Institute for Health and Care Excellence (NICE) has advocated the use of laparoscopic liver resection for a solitary liver metastasis, hepatocellular carcinoma (HCC) and for benign liver tumours and cysts.
- Radiofrequency-assisted liver resection is supported by NICE.
- NICE also endorses the use of ex vivo hepatic resection (operation on the liver outside the body followed by re-implantation) in patients who would otherwise die and have tried all other appropriate treatments.
- NICE recommends that selective internal radiation therapy (SIRT) should be considered as a treatment option for non-resectable colorectal metastases in the liver.
- Chemotherapy may also be a treatment option depending on the primary site. However, if there is co-existing extensive extrahepatic disease, prognosis is usually guarded.
- Deposits from colorectal cancer seem to have a better prognosis.
- The prognosis will depend on the extent of liver metastases and other metastatic spread, the nature and stage of the primary cancer and comorbidities.
- People with secondary liver cancer do not usually die as a direct result of the liver metastases but for some other reason - for example, a chest infection or renal impairment.
Further reading and references
; NICE Interventional Procedure Guidance, May 2014
; NICE Interventional Procedure Guidance, February 2013
; NICE Interventional Procedure Guidance, April 2016
; Interventional oncologic approaches to liver metastases. Radiology. 2013 Feb266(2):407-30. doi: 10.1148/radiol.12112544.
; Useless and dangerous - fine needle aspiration of hepatic colorectal metastases. BMJ. 2004 Feb 28328(7438):507-8.
; NICE Interventional Procedure Guidance, May 2014
; Role of surgery in colorectal cancer liver metastases. World J Gastroenterol. 2014 May 2820(20):6113-22. doi: 10.3748/wjg.v20.i20.6113.
; Surgical management of noncolorectal cancer liver metastases. Cancer. 2014 Oct 15120(20):3111-21. doi: 10.1002/cncr.28743. Epub 2014 Jun 26.
; Liver transplantation for hepatic tumors: a systematic review. World J Gastroenterol. 2014 May 1420(18):5345-52. doi: 10.3748/wjg.v20.i18.5345.
; Liver transplantation for malignancies. J Gastrointest Cancer. 2014 Sep45(3):353-62. doi: 10.1007/s12029-014-9590-2.
; NICE Interventional Procedure Guideline, December 2009
; Radiofrequency ablation of liver tumors. Semin Intervent Radiol. 2013 Mar30(1):49-55. doi: 10.1055/s-0033-1333653.
; Radiofrequency ablation of primary and metastatic liver tumors: a critical review of the literature. Am J Surg. 2008 Apr195(4):508-20.
; NICE Interventional Procedure Guidance, July 2005
; NICE Interventional Procedure Guidance, February 2007
; NICE Interventional Procedure Guidance, April 2009
; NICE Interventional Procedure Guidance, July 2011