The liver is a relatively common site for the development of primary cancers (hepatocellular carcinoma or HCC), and for the secondary spread of cancers from another site (often from colorectal cancers or other cancers in the body.)
Primary liver tumors:
The majority of primary liver tumours are hepatocellular carcinomas (HCC), with a smaller subset of other types of cancers such as cholangiocarcinomas (cancer arising from the bile ducts.)
Incidence of HCC is highest in Asia and sub-Saharan Africa with as many as 120 cases per 100,000. Although anyone can develop HCC certain risk factors are associated with its development such as: liver cirrhosis (the effect of longstanding liver disease leading to replacement of liver tissue by scar tissue and regenerative nodules); alcohol use; hepatitis B and C infection; anabolic steroid use; genetic haemochromatosis and aflatoxin exposure (a toxin from a certain species of fungus.).
Secondary liver tumors
The liver is a common site for spread from other sites in the body, largely due to its dual blood supply from the hepatic artery and the portal vein. In the majority, liver metastases (cancer deposits spread from elsewhere) are multiple and affect both lobes. Liver metastases are only solitary in approximately 10%.
The clinical presentation of hepatocellular carcinomas tends to be of slow onset and includes symptoms such as fever of unknown origin, abdominal pain, malaise, weight loss and liver enlargement. Jaundice (yellow discoloration of the skin and eyes) is unusual.
Occasionally the clinical presentation of hepatocellular carcinoma can be acute and includes bleeding or hepatic rupture.
Liver function tests can be normal. Alpha-fetoprotein (AFP) levels may be elevated because this protein is commonly produced by HCC; however, this is an insensitive marker because AFP levels may be normal in more than one third of patients.
Symptoms of metastatic liver disease may be few, and the extent of liver involvement on images may be surprising, often with little clinical or laboratory evidence suggestive of abnormal liver function.The only physical sign may be enlargement of the liver, however about 30% of patients with liver metastases (cancer deposits) have a normal-sized liver. With large liver metastases or with tumours that are critically close to the bile ducts, signs of obstructive jaundice may be present and results of liver function tests may be abnormal. Patients may have weight loss with malaise and abdominal enlargement due to liver enlargement, ascites (fluid within the abdominal cavity), or both.
They are commonly diagnosed using ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) scans that are reported by a radiologist. These will provide information about the number, size and characteristics of lesions in the liver.
If there is a question about whether these are malignant (cancerous) lesions then a biopsy may be required which involves the sampling of tissue via the introduction of a fine needle into the liver under ultrasound or CT guidance, under local anaesthetic or intravenous sedation.
There are three main IR treatment options:-.
Chemoembolization (TACE) and (DEB):
Chemoembolization is a method used to deliver chemotherapy medication directly to liver tumors — either primary tumors that originated in the liver, or metastases that migrated to the liver from cancers at other sites. Even in cases where chemoembolization is not curative, this approach may relieve a patient’s symptoms and extend survival.
Doctors begin the procedure by inserting a catheter into a blood vessel in the patient’s groin and advancing it into the specific artery supplying the liver. The doctor then injects a dye and visualizes the tumor and blood vessels on an x-ray to determine the condition of the portal vein (a major blood vessel in the liver) and assess blood supply to the tumor.
The physician then injects an emulsion of anticancer drugs and radiopaque oil through a catheter selectively placed into the artery feeding the tumor. This mixture keeps a high concentration of medication in contact with the tumor for a period of time longer than that associated with traditional systemic chemotherapy. After the treatment is administered, the catheter is withdrawn, and the patient can usually return home after an overnight stay in the hospital.
Chemoembolization offers several advantages over traditional systemic chemotherapy: Prolonging the time the medication stays in contact with the tumor — up to as much as a month — increases the treatment’s effectiveness. Moreover, because the medication is delivered only to the tumor — rather than administered throughout the patient’s bloodstream — healthy tissues are spared from side effects, allowing doctors to administer dosages that are up to 200 times greater than those used in conventional chemotherapy. The substances that are part of the injected mixture not only hold the medication in place, but also block the blood supply to the tumor — depriving it of oxygen and nutrients and thereby halting its growth.
Radioembolization, is a technique, similar to chemoembolization, which allows delivery of localized treatment to primary or metastatic liver tumors. Whereas chemotherapy medication is the treatment delivered into the arteries supplying the tumors during chemoembolization, during Radioembolization the medication injected into these arteries consists of tiny beads coated with a radioactive material, Yttrium-90. These beads become lodged in the tumors. The radiation from these beads gradually decreases over the next 2 week, all while continuously destroying the cancerous cells. The tumor killing radiation from these beads travels only 1/16” through tissue so it does not travel outside of the patient’s body. This targeted approach to radiation delivery, allows much higher treatment radiation doses to be directly and safely delivered to the tumor than conventional radiation. This enables pin point delivery of radiation protecting the surrounding normal tissues.
Doctors are also using interventional radiology techniques to apply heating, freezing, or substances such as acetic acid or ethanol directly into tumors as a means of killing cancer cells. This type of treatment, called tumor ablation, is a relatively new technique that is showing promising results for treating cancer.
- Rapid relief from symptoms.
- The imaging techniques allow accurate diagnosis and treatment using cutting-edge equipment. Diagnosis is reconfirmed during procedure.
- Minimally invasive procedures are performed through a small hole in the skin, minimising the patient’s discomfort and recovery time. There won’t be any scar.
- Most procedures can be performed on an outpatient basis or require only a short hospital stay. As interventional procedures tend to require only local anaesthesia, hospital stays are very short, with patients frequently going home the day the procedure is performed.
- Patients who undergo IR procedures experience less pain during and after the procedure than patients undergoing surgical procedures. Post-procedural care is provided, along with follow-up imaging to confirm if the treatment has been successful.
- Minimal damage to surrounding vital anatomical structures with no significant structural weakness.
- No or negligible blood loss. No requirement of blood transfusion.
- Return to work and other normal activities usually within the first few days after the procedure.
- Low risk compared to surgery. The techniques can be used in very sick patients who are unfit for surgery.
- Overall procedure is less expensive than surgery or other alternatives.