Understanding Cancer-Related Tests: Liver Function Test (LFT)

The liver is an important organ that is responsible for processing blood and medications, including cancer treatments, from the body. Together, all the following tests give information about how well the liver is working. Because some cancers and treatments can cause damage to the liver, your oncology team may monitor these tests frequently during and after your treatment. 

Liver Function Tests (LFTs) are part of the Complete Metabolic Panel. However, these tests can also be ordered independently by your physician. 

 AST (aspartate aminotransferase) and ALT (alanine aminotransferase) 

  • AST is an enzyme that helps break down molecules found in proteins. 

    • A high level may indicate damage to the liver, liver disease, or damage to muscles.   

  • ALT is an enzyme that creates energy for the liver from proteins. 

    • When the liver is not working properly, the liver may send ALT into the bloodstream and show increased levels on testing. 

  • Elevated liver enzymes may or may not cause symptoms. If symptoms are present these may include:  

    • Jaundice, or yellowing of the skin or whites of eyes 

    • Dark urine 

    • Itchy skin 

    • Stomach pain 

    • Nausea  

    • Vomiting 

    • Fatigue 

    • Loss of appetite 

    • Light colored stools 

 ALP (alkaline phosphatase) 

  • ALP is an enzyme found in the liver, bones, kidneys, and intestines that also helps to break down proteins. 

  • Elevations in ALP may indicate a variety of conditions that can be caused by cancer or side effects of cancer treatment, including the following:  

    • Liver damage or disease, disease in the bones – such as a bone metastasis – and other bone disorders, thyroid, or parathyroid conditions

  • If your ALP is unexpectedly high, your team may order additional tests to better understand what organ is producing the extra ALP.  

  • Low ALP may include the following causes:  

    • Low levels of certain nutrients including zinc and magnesium; malnutrition; or hypothyroidism

  • It is important to note that abnormal ALP levels do not always mean that there is a medical problem or side effect that needs to be treated. Things like age, pregnancy, medications, testing errors, and other non-cancer related disease may cause abnormal levels. 

  • Abnormal levels of ALP may or may not cause symptoms. The symptoms may vary greatly depending on the problem or condition associated with the elevated ALP.  


  • Bilirubin is a yellow material created during the normal process that breaks down red blood cells. Because it passes through the liver before it is excreted by the body, measuring it helps us understand how the liver is working. 

  • A low level is normal. A high level may be caused by an issue with your liver or gallbladder. This level can affect how your medicines are processed by your body. 

  • Elevated bilirubin in the blood may cause jaundice.  

  • Depending on what is causing the extra bilirubin to be in the blood, you may also experience: 

    • Fatigue, fever, loss of appetite, or pain in the upper part of your abdomen 

 Total Protein 

  • Total protein measures the amount of albumin and globulin in your blood. 

  • Abnormal results can indicate liver and/or kidney disease as well as malnutrition/malabsorption.

  • High total protein will rarely cause symptoms. 

  • Signs of low total protein can include: 

    • Infection, fatigue, brittle hair/nails, or mood changes


  • Albumin is a type of protein that is made by your liver. Albumin helps keep the fluid in your blood/blood vessels and prevents build up in organs like your stomach and lungs. 

  • Abnormal results can indicate liver or kidney disease.

  • Signs of low albumin can include: 

    • Swelling in extremities or abdomen, difficulty breathing, fatigue, jaundice, excessive urination, or low muscle tone 

  • Signs of high albumin can include: 

    • Fatigue, bruising, weight loss, swelling, or stool color changes

When to Contact Your Doctor, Health Care Provider, or Iris Oncology Nurse

  • You are experiencing fever (temperature ≥100.4) 

  • You have unusual bleeding, bruising, or red spots under your skin 

  • You are experiencing dizziness or shortness of breath 

  • You have concerns about any symptoms that you are experiencing 


Alkaline phosphatase (ALP): What it is, causes & treatment. Cleveland Clinic. (2021). Retrieved January 19, 2022.

Mayo Clinic Staff. (2020, February 21). Liver disease. Mayo Clinic. Retrieved January 19, 2022.

OncoLink Team. (2020). Comprehensive metabolic panel. OncoLink. Retrieved January 19, 2022. 

Yin, L. K., & Tong, K. S. (2009, August 31). Elevated alt and AST in an asymptomatic person: What the primary care doctor should do? Malaysian family physician: the official journal of the Academy of Family Physicians of Malaysia. Retrieved January 19, 2022.