In spite of all the drawbacks/criticism of AFP blood test for liver cancer, it is still the most discriminatory lab test for the detection of liver cancer, especially in people or communities prone to Heptocellular carcinoma.
It is often difficult to detect and diagnose liver cancer early or at entry point as its signs and symptoms are vague and non specific. When these appear the cancer had already reached its zenith or last stage of degeneration. Small hard tumors located in liver are hard to feel as most of liver is covered by right rib cage. By the time the tumoris felt by the patient or on physical examination by doctor the tumor is already large. Neither there are any world wide accepted screening tests nor the efficacy of these tests is reliable .For details on this subject, see my factoid ,”Can Populations Be Screened for Detection of Cancer”? Those People who are vulnerable to cancer; have generally past history of cirrhosis of liver. Cirrhosis is fatty liver. It may lead to necrosis of liver than fibrosis and ultimately cancer. Liver cancer screening especially in families who have paste history of liver cancer or any other cancer should have screening of liver. Doctors generally recommend screening tests for liver every six months. Alpha feto protein blood tests along with other scanning tests should be undertaken.
One thing should be kept in mind that two kinds of changes occur in human organs .The functional changes are confidently managed by doctors and are reversible. But when these changes give way to structural changes in organs than possibility of cure is lessened and almost diminished. Anorexia, decrease in hunger, heaviness in liver, discomfort in liver after eating languor and malaise, these are functional changes of liver. If attended or addressed early these can be fully reversed in a short span of time. If these structural changes continue to grow unnoticed for long time or are ignored willfully: than these are replaced by pains. The small structural lesions ultimately lead to the development of liver cancer in the patient. So the pathology of liver must be under constant scan and vigil of the patients.
Tumor marker AFP
Though the application of tumor marker for screening cancer is of doubtful nature and can not be relied on blindly yet it provides some significant clues for the detection of cancer in patients. There is an old saying,” something is better than nothing. “The blood tests for alpha feto protein lead us to liver cancer though we can not neither rely nor follow these screening tests blindly. In Africa where heptocellular carcinoma has taken the epidemic form this test is proving very helpful tool to doctor’s community for screening patients with liver cancer. It may prove also important tool to patients who are HBsAg positive. What is alpha feto protein? Alpha-Feto protein is a normal fetal serum protein synthesized by the liver; it is a major component of blood and fetal plasma.
• Germ cell tumor in boys Teratoma
• Dysgerminoma of ovaries in girls
Drawbacks of this tumor marker
• AFP is also raised in blood of normal pregnant ladies
• AFP blood tests may also be employed for people who are at high risk of liver cancer
• Only 50% liver cancer cell manufactures this protein. In some cancers it is totally normal in the blood of patients.
• When the AFP level is raised above 500 ng often the tumor is so large that it had already metastasized to other organs.
• APP level may also be elevated in some diseases other than cancer
• In spite of the drawbacks and anomalies of this test, this test can save the life of many patients if along with this test the attending physician conducts some more reliable tests
Even after ruling out other possibilities and factors for raised levels of AFP; if the AFP protein is high in blood tests of a patient than ultrasound may be undertaken. Ultrasound is a screening test that uses sound waves and their echoes to produce a picture of internal organs or masses (tumors). It is very efficient technique to detect cancers. A small instrument called a transducer emits sound waves and picks up the echoes as they bounce off the organs. The echoes are converted by a computer into a black-and-white imagery. The doctor by analyzing these images can detect the presence of tumor in the liver. This test can show masses (tumors) growing in the liver, which can then be tested for cancer, by biopsy.
Prevention is better than cure. Patients afflicted with liver cirrhosis must undertake these screening tests as early as possible to prevent further damage to their liver cells. One scientist has highlighted the importance of AFP test for cancer patients by saying,” the single most discriminating laboratory test indicative of malignant disease now available” the elevated level of AFP more than 500 ng/ml certainly indicates liver carcinoma; If the AFP findings in normal adults, children and infants are more than 20ng/ml than further evaluation is must to rule out the underlying pathology/cancer. The normal range of AFP in adult blood is 0-4ng/ml.