November 9, 2021 – Primary liver cancer or hepatocellular carcinoma (HCC) is the most common form of liver cancer accounting for more than 90% of all cases. HCC represents a major global health challenge as its incidence continues to rise worldwide; by 2025 more than 1 million individuals will be affected by HCC annually.
Asia and Sub-Saharan Africa remain the most affected areas in the world mostly because of the association between HCC and hepatitis B viral infection which is endemic in these regions of the world. Here lies the major problem with HCC, namely the fact it is truly two diseases at once; the underlying liver dysfunction or cirrhosis caused by hepatitis B or C viral infection, alcohol or other toxic insults, and the cancer itself, making the treatment of liver cancer especially challenging.
Although the causes of HCC, such as hepatitis B or C, have been substantially decreased by vaccination for hepatitis B and antiviral drugs that can eradicate hepatitis C viral loads and cure patients of hepatitis C, their benefits will take time because of the long latency period 20 to 30 years from the onset of liver damage to the occurrence of HCC. To make matters worse, the emergence of non-alcoholic fatty liver disease associated with obesity, metabolic syndrome, or diabetes has begun to overtake the other risk factors as a major cause of HCC in the West, which will likely account for a continued high incidence of HCC.
Progress has been made to establish a diagnosis of HCC at an earlier stage of the disease thanks to routine screening programs that have been implemented for patients with known cirrhosis and are therefore at high risk for HCC. Imaging with ultrasound is preferred because it is readily available and relatively inexpensive. For patients at high risk of HCC, the guidelines recommend ultrasound imaging every 6 months with or without serum alpha-fetoprotein (AFP) measurements. Once a diagnosis is established, patients are typically staged using the Barcelona Clinic Liver Cancer staging system which accounts for the patient’s cancer characteristics including tumor size and presence of vascular invasion but adds other features that are unique to HCC such as the underlying liver disease and performance status of the patient.
The best option for a cure is transplantation since both the underlying cirrhosis and HCC are removed at once. Unfortunately, few patients are eligible for such curative therapies. On the other hand, because HCC has a tendency to remain confined to the liver until late in the process, locoregional therapies have been playing a major role in the management of patients with HCC by providing effective treatments in the form of ablation or intraarterial embolotherapy using chemotherapy or radiation delivered precisely under image guidance to the tumor, sparing the healthy liver tissue.
Imaging of HCC is best performed with contrast-enhanced MRI or 4-phase CT scanning. Imaging guidelines using both CT and MRI for HCC have been created to help establish a definitive diagnosis of HCC. Once a treatment has been initiated, treatment response is best assessed using modified RECIST which is based on contrast-enhancement rather than tumor size decrease alone. Indeed, to remain true to the unique aspects of this cancer, HCC tumors may not necessarily decrease in size after a successful treatment. Rather it is the lack of contrast enhancement post-treatment that is the most reliable sign of a favorable response, hence the use of modified criteria to determine whether a patient has responded to therapy. Advancements in screening, surveillance, diagnosis and treatment are helping, especially with the advent of immuno-oncology drugs that have emerged as viable treatment options even for patients with advanced HCC. But much progress is still needed for one of the most lethal cancers in the world.
At Imaging Endpoints, we deploy all available detection and evaluation methodologies, as well as emerging technologies, in the provision of HCC imaging services for clinical trials, always striving to do our part in Connecting Imaging to the CureTM. For more information, please email us at the firstname.lastname@example.org to learn more and arrange time to speak to one of our experts.