A jab against liver cancer
The majority of those with liver cancer have chronic hepatitis or cirrhosis, and understandably, older patients with longstanding liver disease are more likely to develop the cancer.
LIVER cancer, also called hepatocellular carcinoma ((HCC), is the fifth most frequently diagnosed cancer in adult men worldwide and is the second leading cause of cancer-related deaths in the world.
It is also the seventh most commonly diagnosed cancer in adult women and the sixth leading cause of cancer deaths. In most cases, it is an aggressive tumour that occurs in the setting of underlying chronic liver disease.
In Malaysia, liver cancer is the fifth most common cancer affecting men. The majority of our liver cancer patients have hepatitis B, and Malaysians must be made aware that this is one cancer that can be prevented through vaccination against hepatitis B.
Another important cause is hepatitis C, which is responsible for an increasing number of cases in the United States.
Globally, almost 80% of liver cancer cases are due to underlying chronic hepatitis B and C virus infection.
Worldwide, between 250,000 and one million people die each year from liver cancer. Regions that show a high incidence of liver cancer (more than 15 cases per 100,000 population per year) include sub-Saharan Africa, China, Hong Kong and Taiwan. Men are more likely than women to develop the disease.
The majority of those with liver cancer have chronic hepatitis or cirrhosis, and understandably, older patients with longstanding liver disease are more likely to develop the cancer. It is important to note that about 20-56% of those with liver cancer have previously undiagnosed cirrhosis.
In fact, 80% of our patients with liver cancer come too late for definitive treatment, not knowing that they have been harbouring the disease for some time. Those with compensated cirrhosis have an annual risk of 1-8% chance of developing liver cancer, depending on the cause of the cirrhosis. Those with chronic hepatitis have an annual risk of about 1%.
Patients with cirrhosis due to hepatitis B or C have the highest risk of developing HCC. There is growing evidence that non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor for HCC via cirrhosis, although the exact pathogenesis is still uncertain.
Doctors usually screen hepatitis B and C patients for HCC every six months, or three months if cirrhotic, by performing abdominal ultrasound examination and checking serum alpha-fetoprotein levels.
The most effective treatment would be surgical resection. However, most patients are not eligible for this form of treatment as the tumour size may be too large or the underlying liver disease may be too advanced.
Other forms of treatment include liver transplantation, radiofrequency ablation (RFA), percutaneous ethanol injection, transarterial chemoembolisation (TACE), cryoablation, radiation therapy, systemic chemotherapy and molecularly-targeted therapies.
The most appropriate treatment for a particular patient will be decided by the hepatobiliary surgeon, together with the patient. Several factors, including tumour extent and the severity of the underlying liver disease, will be considered.
Potentially curative partial hepatectomy (surgical liver resection) is the optimal treatment for HCC in patients with adequate liver functional reserve. Those eligible for this form of treatment would be someone with a solitary HCC nodule confined to the liver, no radiographic evidence of invasion of the hepatic blood supply, no evidence of portal hypertension and a well-preserved liver function.
Long-term relapse-free survival rates average 40% or more and five-year survival rates as high as 90% are possible in carefully selected patients.
Most surgeons restrict resection to patients with tumours that are 5cm or less in diameter, although patients with a solitary HCC without vascular invasion have a similar survival probability regardless of tumour size.
Understandably, patients with smaller tumours tend to have a better outcome.
Some patients may benefit from liver transplantation if their tumours are unresectable and there is extensive degree of underlying liver dysfunction.
Radiofrequency ablation (RFA) involves the local application of radiofrequency thermal energy to the lesion. With increasing temperature within the tissue, cells begin to die, resulting in a region of necrosis surrounding the electrode.
For cirrhotic patients, some clinicians restrict RFA to those with mild or moderate disease.
Percutaneous ethanol injection (PEI) can be considered for patients with small HCCs who are not candidates for resection due to their poor functional hepatic reserve.
Before the advent of RFA, PEI was the most widely accepted minimally-invasive method for treating such patients.
The greater efficacy of RFA has however, made this procedure less popular despite its relatively lower cost, good clinical results and the use of only minimal equipment.
Transarterial chemoembolisation (TACE) is based on the principle that the majority of blood supply to HCCs is derived from the hepatic artery. TACE involves the administration of cytotoxic chemotherapy directly to the tumour and is preferred for the treatment of large unresectable HCCs that are not amenable to other treatments such as resection or RFA.
Some surgeons use it as a “bridging therapy” prior to transplant.
Molecularly-targeted therapy is now an option for patients with inoperable cancer.
In 2007, a multi-centre European randomised SHARP trial demonstrated a modest, though statistically significant, survival benefit for sorafenib (a multi-targeted tyrosine kinase inhibitor) over supportive care alone in patients with advanced HCC.
These data established sorafenib monotherapy as the new reference standard systemic treatment for advanced HCC. The drug is generally well tolerated, although some patients may experience rash and hand-foot skin reactions.
A special programme called the Nexavar Patient Assistance Program (NexPAP), initiated by Bayer HealthCare working in partnership with the Malaysian Liver Foundation (MLF), is available to assist Malaysian patients who have been diagnosed with inoperable HCC and have been prescribed by their doctors to use sorafenib.
The programme aims to assist patients to continue with the drug for as along as medically required, provided they fulfill the eligibility criteria. Those who wish to get more details can contact MLF.
This article is to alert readers that HCC associated with hepatitis B can be prevented, and patients with chronic hepatitis B and C must remain vigilant and religiously adhere to their follow-up visits with their doctors so as not to miss early detection of HCC.
Those with HCC have several treatment options depending on their overall medical condition, the stage and extent of the tumour, and the underlying liver reserve.
Source: The Star
Published: 21 Sep 2014
Category: Features, Technology & Devices
