Essay
By Dr. Angela M. Dumbuya, DNP/Oncology Nurse Practitioner
John B. Amos Cancer Center, Columbus, Georgia, USA.
Introduction
The liver serves many important functions. These include breaking down and storing many nutrients, secretion of bile juices that are stored in the gallbladder and later transported into the intestines, and filtering and breaking down toxic wastes in the blood. All of these functions can be compromised by liver cancer. The most common type of liver cancer is hepatocellular carcinoma (HCC) which begins in the liver cells or hepatocytes cells.
Worldwide it is the fifth most diagnosed cancer in men (554,000 annually) and the ninth most diagnosed cancer in women (228,000 annually). It is the second leading cause of cancer deaths in men (478,000 per year) and the sixth leading cause of cancer deaths in women (218,000 per year). Eighty-five percent of liver cancer occurs in the developing countries. The highest incidences are in East and Southeast Asia, and Central and West Africa. Eighty percent of cases of HCC are caused by hepatitis B&C viral infections. Sierra Leone ranks 11th worldwide with 18.2 per 100,000 cases a year of liver cancer. (GLOBOCAN 2008).
Risk Factors for Liver Cancer
So what causes liver cancer? What causes liver cancer is still a mystery, and why certain individuals get liver cancer while others don’t is also very difficult to explain. What we do know is that certain individuals with known liver cancer risk factors are more likely than others to develop HCC. A risk factor is anything that affects one’s chances of getting a disease. Globally long term chronic infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) is the most common risk factor for developing liver cancer.
HCC can develop after many years of hepatitis viral infections. Chronic infection with both HBV and HCV can lead to cirrhosis of the liver. (ACS 2013). Chronic alcohol abuse causes further damage to the liver resulting in the growth of scar tissue. The parasite schistosomiasis, which is found in Asia, Africa, and South America, can also cause cirrhosis of the liver. Drinking water which has been contaminated by arsenic found in some wells can increase the risk factors for liver cancer. These wells are typically found in East Asia and some parts of the United States.
Hemochromatosis (iron overload) has also been linked to this deadly disease. Iron overload is often derived from cast iron cooking pots which are widely used in sub-Saharan Africa. Cast iron pots are an excellent source of iron for people with low levels of iron. The key is to know one’s iron (ferritin) levels in the blood. Certain medications such as anabolic steroids can also cause cirrhosis of the liver.
Aflatoxin B1 is a harmful substance found in molds and can contaminate staple African and Asian foods like rice, ground nuts, and corn, wheat, and soy beans. This fungus is found in hot and humid environment. With adequate climate control methods especially in storage facilities, the presence of Aflatoxin in foodstuffs can be eliminated or ameliorated.
Obesity also increases the risk of liver cancer. People with type II diabetes also have an increased risk of liver cancer especially when combined with HBV and HCV infection.
Signs and Symptoms of Liver Cancer
Most of the signs and symptoms of liver cancer present themselves late when the disease is no longer curable. However, a few signs may show up early and these include unintentional weight loss, lack of appetite, feeling very full after eating a small meal, pain on the right side of the abdomen, swelling or fluid buildup in the abdomen, itching and yellowing of the skin, eyes and nails, enlarged veins in the abdomen, nausea, vomiting, fatigue, and tea-color urine.
Annual checkups with primary care providers are very helpful ways of detecting liver cancer and prolonging life.
Screening, Diagnosing, and Treating Liver Cancer
Most liver cancers are diagnosed late because the characteristics of the disease are oftentimes absent or manifest themselves late. Late diagnosis makes the disease incurable. When patient characteristics are factored in, most people with liver cancer, on average, live between six to twenty months from the time they are diagnosed with the disease. Therefore, for people with risk factors (cirrhosis, HBV, HCV) the American Association for the Study of Liver Disease and the European Society for Gastrointestinal Endoscopy have recommended imaging patients every six to twelve months. They also recommend taking a medical history and doing a physical exam to determine whether enlargement of the liver or spleen has taken place.
Blood tests may also be done to check for liver cancer. One of the most significant blood tests is the Alpha-fetoprotein (AFP). AFP is a protein and high amounts of it are found in the blood of fetuses but dissipate shortly after the baby is born. When AFP is found in the blood of adults, inevitably it suggests the presence of liver cancer. Other blood tests may be done to determine how well the liver is working. The presence of the HBV surface antigen (HbsAg) in the blood is an indicator of chronic infection. A blood test for Aflatoxin B1 may also be done.
Other diagnostic and screening tests for liver cancer include an ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). These scans check for any mass and blood flow to the liver. Ultimately, liver cancer is diagnosed by taking a piece of tumor from the liver (biopsy) and testing it under a microscope for the presence of cancer cells.
The goal of liver cancer therapy is to remove the cancer. Surgery is the primary cure if the cancer is small and has not spread to other areas of the body. Parts of the liver (partial hepatectomy) are removed during this procedure and the remaining liver will then regenerate. Liver transplant is also an option for people whose cancerous tumors are small and are contained in the liver. Radiofrequency ablation or the killing of cancer cells with excessive heat generated by a probe that is inserted through the skin into the liver is also an option. Embolization is the process whereby blood flow to the hepatic artery is blocked to starve the cancer cells of nutrients. Liver cancer is also treated with radiation therapy, chemotherapy, and targeted therapy.
Control programs for Liver Cancer
Worldwide, the most significant risk factor for liver cancer is chronic infection with hepatitis B&C viruses. These viruses are usually spread from person to person through blood, semen, or other body fluids. This can happen through unprotected sexual contact with an infected person, and sharing needles, syringes, or other drug-injection equipment. Hepatitis B&C can also be passed on from an infected mother to her baby at birth. According to World Cancer 2014, the areas of the world where liver cancer is prevalent also experience high rates of HBV and HCV infections among the populations and high exposure rates to Aflatoxins.
Early HBV vaccine trials in the 1980s concluded that about 75 percent of chronic infections could be prevented if people are vaccinated. The cure for HCV is very expensive and may not be available in many low income countries. As a result steps should be taken to prevent infection from the virus through public education about sexually transmitted diseases (STDs), unprotected sex, and sharing of contaminated needles by drug users. Healthcare workers also need to be educated about effectively sterilizing medical equipment especially in the fields of dentistry and surgery. Blood transfusion has been a source of HBV and HCV infection more so in areas were blood banks do not effectively monitor their collection processes. All donated blood should be effectively tested for blood-borne infections, viruses, and bacteria. Liver cancer control programs also have to target the reduction of Aflatoxins in agricultural communities where liver cancer is on the rise. Storage of harvested crops in a controlled environment can reduce the presence of Aflatoxin. (Turner P. C., Sylla A 2005). Government agencies in Africa must provide regulatory services to screen for Aflatoxins and to prevent crop contamination.
Public service awareness campaigns against excessive alcohol use would help educate the public about link between alcohol and liver damage. Smoking cessation programs would also be beneficial in reducing the rates of all types of cancers. Obese people have a higher potential of developing fatty liver disease and type II diabetes. Those at risk should be encouraged to participate in weight loss programs and consume a healthy diet high in vegetables, whole grain, and fruits. Often obesity in most African countries is seen as a sign of wealth; we must work hard to change this myth. Obesity is the source of many of the world’s health problems. Public health programs should incorporate the use vaccines to help prevent HBV infection; such vaccines have been available since the 1980s.
Conclusion
This essay has discussed hepatitis infection, cirrhosis of the liver, and Aflatoxins as the three most important risk factors for liver cancer. These risk factors can be prevented or ameliorated through public education, government policies, sound public health programs, and community involvement. The incidence of liver cancer in African is very high and continues to rise because of the high prevalence of hepatitis B&C infections.
It is no coincidence that liver cancer is low in countries where hepatitis infection is low and government policies are in place to screen and prevent contamination with Aflatoxins. These countries have put in place public health programs that include reporting requirements, treatment of STDs, vaccination, and treatment for hepatitis. These programs have been tried and tested and they worked. Countries where liver cancer is prevalent and on the rise should adopt and put these programs in place.
Comments