Hepatocellular carcinoma is the most common type of primary liver cancer. About 42,030 new cases and about 31,780 deaths due to primary liver cancer, including intrahepatic bile duct cancers, are expected in 2019 in the US. About three-fourths of these liver cancers will be hepatocellular carcinoma. Liver cancer is about 3 times more common in men than in women. However, it is more common outside the US, particularly in East Asia and sub-Saharan Africa, where the incidence generally parallels geographic prevalence of chronic hepatitis B virus (HBV) infection.
Hepatocellular carcinoma is usually a complication of cirrhosis.
The presence of HBV increases risk of hepatocellular carcinoma by > 100-fold among HBV carriers. Incorporation of HBV-DNA into the host’s genome may initiate malignant transformation, even in the absence of chronic hepatitis or cirrhosis.
Other disorders that cause hepatocellular carcinoma include cirrhosis due to chronic hepatitis C virus (HCV) infection, hemochromatosis, and alcoholic cirrhosis. Similar to HBV infection, hepatocellular carcinoma can develop in patients with noncirrhotic nonalcoholic steatohepatitis. Patients with cirrhosis due to other conditions are also at increased risk.
Environmental carcinogens may play a role; eg, ingestion of food contaminated with fungal aflatoxins is believed to contribute to the high incidence of hepatocellular carcinoma in subtropical regions.
Most commonly, previously stable patients with cirrhosis present with abdominal pain, weight loss, right upper quadrant mass, and unexplained deterioration. Fever may occur. In a few patients, the first manifestation of hepatocellular carcinoma is bloody ascites, shock, or peritonitis, caused by hemorrhage of the tumor. Occasionally, a hepatic friction rub or bruit develops.
Occasionally, systemic metabolic complications, including hypoglycemia, erythrocytosis, hypercalcemia, and hyperlipidemia, occur. These complications may manifest clinically.
Clinicians suspect hepatocellular carcinoma if
They feel an enlarged liver.
Unexplained decompensation of chronic liver disease develops.
An imaging test detects a mass in the right upper quadrant of the abdomen during an examination done for other reasons, especially if patients have cirrhosis.
However, screening programs enable clinicians to detect many hepatocellular carcinomas before symptoms develop.
Diagnosis is based on AFP measurement and an imaging test. In adults, AFP signifies dedifferentiation of hepatocytes, which most often indicates hepatocellular carcinoma; 40 to 65% of patients with the cancer have high AFP levels (> 400 mcg/L). High levels are otherwise rare, except in teratocarcinoma of the testis, a much less common tumor. Lower values are less specific and can occur with hepatocellular regeneration (eg, in hepatitis). Other blood tests, such as AFP-L3 (an AFP isoform) and des-gamma–carboxyprothrombin, are being studied as markers to be used for early detection of hepatocellular carcinoma.
Depending on local preferences and capabilities, the first imaging test may be contrast-enhanced CT, ultrasonography, or MRI. Contrast imaging must be ordered as a triple-phase protocol because the third, or delayed-contrast phase is essential for a radiographic diagnosis of hepatocellular carcinoma. Hepatic arteriography is occasionally helpful in equivocal cases and can be used to outline the vascular anatomy when ablation or surgery is planned.
Radiographic criteria known as the LI-RADS (liver imaging reporting and data system) are used to diagnosis hepatocellular carcinoma (HCC) with high sensitivity with key radiographic features, including presence of arterial hyperenhancement, pseudocapsule around the lesion, washout of contrast on delayed-phase imaging, and interval growth of the lesion from the prior scan (1).
If imaging shows characteristic findings and AFP is elevated, the diagnosis is clear. However, rarely, liver biopsy, often guided by ultrasonography or CT, is indicated for definitive diagnosis.
If a hepatocellular carcinoma is diagnosed, evaluation usually includes chest CT without contrast, imaging of the portal vein (if not already done) by MRI or CT with contrast to exclude thrombosis, and sometimes bone scanning, if the AFP is particularly elevated.
Various systems can be used to stage hepatocellular carcinoma; none is universally used. One system is the TNM system, based on the following (see table Staging Hepatocellular Carcinoma):
Numbers (0 to 4) are added after T, N, and M to indicate increasing severity.
Staging Hepatocellular Carcinoma*
Other scoring systems include the Okuda and the Barcelona-Clinic Liver Cancer staging systems. In addition to tumor size, local extension, and metastases, these systems incorporate information about the severity of liver disease.
An increasing number of hepatocellular carcinomas are being detected through screening programs. Screening patients with cirrhosis is reasonable, although this measure is controversial and has not been shown to reduce mortality. One common screening method is ultrasonography every 6 or 12 months. However, in obese patients, because sensitivity of ultrasonography is limited in them, alternating ultrasonography with MRI or CT should be considered for screening. Many experts advise screening patients with long-standing hepatitis B even when cirrhosis is absent. Patients with nonalcoholic steatohepatitis (NASH) are now recognized to account for 50% of cases of noncirrhotic HCC (2). However, despite this recognition, screening is not yet recommended for such patients.
Mitchell DG, Bruix J, Sherman M, et al: LI-RADS (liver imaging reporting and data system): Summary, discussion, and consensus of the LI-RADS Management Working Group and future directions. Hepatology 61(3):1056-1065. 2015. doi: 10.1002/hep.27304.
Galle PR, Forner A, Llovet JM, et al: EASL clinical practice guidelines: Management of hepatocellular carcinoma. J Hepatol 69:182-236, 2018.
Treatment of hepatocellular carcinoma depends on its stage (1) and the underlying severity of liver disease.
For single tumors < 5 cm or ≤ 3 tumors that are all ≤ 3 cm and that are limited to the liver, without microvascular invasion, and if AFP is < 500 mcg/L, liver transplantation appears to result in as good a prognosis as liver transplantation done for noncancerous disorders. Liver transplantation can be curative. These Milan criteria are used to identify patients with hepatocellular carcinoma who are good candidates for liver transplantation (2). The American Association for the Study of Liver Diseases (AASLD) 2018 guidelines also use the Milan criteria for selection of patients for liver transplantation (3).
In selected patients with singular tumors < 5 cm and no portal hypertension, surgical resection is potentially curative, with 5-year survival rates of 60 to 80%.
Ablative treatments (eg, hepatic arterial chemoembolization, yttrium-90 microsphere embolization [selective internal radiation therapy, or SIRT], drug-eluting bead transarterial embolization, radiofrequency ablation) provide palliation and slow tumor growth; they are used when patients are awaiting liver transplantation. For small tumors < 2 cm, radiofrequency ablation (RFA) is potentially curative.
If the tumor is large (> 5 cm), is multifocal, has invaded the portal vein, or is metastatic (ie, stage III or higher), prognosis is poor (eg, 5-year survival rates of about 5% or less). Radiation therapy is usually ineffective. Sorafenib only modestly improves outcomes, with a median survival of 10.7 months as compared to 7.9 months with placebo (4). Several new chemotherapy agents prolong survival longer or cause fewer side effects than sorafenib; these include levatinib, regorafenib, and immunotherapy such as nivolumab. Progression-free survival was higher with levatinib than with sorafenib and is an alternate first-line therapy. The other new agents are second-line options (5).
Bruix J, Reig M, Sherman M: Evidence-based diagnosis, staging, and treatment of patients with hepatocellular carcinoma. Gastroenterology 50(4):835-853, 2016. doi: 10.1053/j.gastro.2015.12.041.
Mazzaferro V, Regalia E, Dorci R, et al: Liver transplantation for the treatment of small hepatocellular carcinomas in patients with cirrhosis. N Engl J Med 334 (11): 693-700, 1996. doi: 10.1056/NEJM199603143341104.
Marrero JA, Kulik LM, Sirlin CB, et al: Diagnosis, staging, and management of hepatocellular carcinoma: 2018 practice guidance by the AASLD. Hepatology 68 (2):723-750, 2018. doi: 10.1002/hep.29913.
Llovet JM, Ricci S, Mazzaferro V, et al: Sorafenib in advanced hepatocellular carcinoma. N Engl J Med 359:378–390, 2018. doiI: 10.1056/NEJMoa0708857.
European Association for the Study of the Liver:EASL clinical practice guidelines: Management of hepatocellular carcinoma. J Hepatol 69:182-236, 2018.
Hepatocellular carcinoma is usually a complication of cirrhosis and is most common in parts of the world where hepatitis B is prevalent.
Consider the diagnosis if physical examination or an imaging test detects an enlarged liver or if chronic liver disease worsens unexpectedly.
Diagnose hepatocellular carcinoma based on the AFP level and liver imaging results, and stage it using chest CT without contrast, portal vein imaging, and sometimes bone scanning.
Consider liver transplantation if tumors are within the Milan criteria.
Prevention involves use of the hepatitis B vaccine and management of disorders that can cause cirrhosis.