Primary versus Secondary Liver Cancer: What is the Difference?


All cancers, even liver cancer, originate in the cells of your body.  Cells are the smallest unit of life that can replicate independently.  This is the reason we often refer to them as the “building blocks of life.”

In short, cells divide into new cells in order for you to grow, heal, and repair.  And, they do this when your body tells them to.

Further, cells stop dividing when your body tells them they are no longer needed or cannot be repaired.  The ending result is a dead cell that your body efficiently rids itself of as waste.

Cancer develops when the above-explained cellular process goes wrong.

When your cell continues to divide and multiply, despite the signal from your body to stop, it becomes abnormal.  This repeated process results in a lump of abnormal cells, more commonly called a tumor.


Tumors are classified into two categories:

  1. Benign Tumors – Benign tumors are harmless, and while they can continue to grow, they cannot spread to nearby tissues in your body.
  2. Malignant Tumors – Malignant tumors on the other hand, are cancerous and can grow into nearby tissue.


That being said, malignant tumors can be furthered classified into two separate types:

  1. Primary Cancers
  2. Secondary Cancers

Today we are going to discuss the differences between primary and secondary liver cancer and why knowing the difference is important to your cancer treatment and overall health.


What is Primary Liver Cancer?

Primary cancer is aptly named after its site of origination.  For instance, primary liver cancer is a disease in which abnormal cells begin to form in the tissues of the liver.


If your liver physician determines that these cells are malignant, you will be diagnosed as having primary liver cancer.


There are two types of primary liver cancer:

  1. Hepatocellular carcinoma
  2. Cholangiocarcinoma (otherwise known as bile duct cancer)


Several things increase your risk of getting primary liver cancer:

  • Having hepatitis B or C
  • Cirrhosis of the liver due to hepatitis or alcoholism
  • Fatty liver disease
  • A severe liver injury paired with cirrhosis
  • Hemochromatosis
  • Aflatoxin poisoning

Treating primary liver cancer can be a long and arduous journey.  Your Baltimore liver cancer surgeon will likely discuss several different treatment options with you so that you can have the best overall results.


Some primary liver cancer treatment options include:

  • Chemotherapy
  • Radiation therapy
  • Alcohol injections
  • Surgery (including a liver transplant)

If you are diagnosed with primary liver cancer, it is important you get specialized care right away.  You will need to visit specialists, liver surgeons, and possibly a treatment center in your battle against this scary disease.


What is Secondary Liver Cancer?

Secondary liver cancer is a cancer that started somewhere else in your body and has spread, or metastasized, to your liver.  For example, if you were originally diagnosed with primary colon cancer, and the abnormal cells spread to your liver, you now have secondary liver cancer, or more specifically, colorectal liver metastasis.

Primary cancer cells typically spread to other parts of your body via your bloodstream or lymphatic system.

The lymphatic system is responsible for making and storing cells that fight infection.  Therefore, cancer cells can easily travel the length of your body via the lymphatic system because infection-fighting cells are constantly transporting to all areas of your body.

Once a primary cancer from one part of your body has spread to your liver and becomes secondary liver cancer, the cells of the secondary liver cancer consist of abnormal, cancerous cells from the primary cancer.  Again using our example, this means that colorectal liver metastasis consists of colon cancer cells within the liver itself.

Once a cancerous cell is stuck in a blood vessel or lymph node, a new tumor begins to grow.  This is now the secondary cancer site.


The most common places for secondary cancers to grow include:

  • Lungs
  • Lymph nodes
  • Bones
  • Brain
  • Skin
  • Liver

Every type of cancer has its own cell structure that is identifiable using various tests.  This is why detecting secondary liver cancer is usually easy, despite having originated in other areas of the body.


Treating Secondary Liver Cancer

When your physician determines that you have secondary liver cancer, the cancer must be treated according to the treatment options for the primary cancer, rather than as a cancer of the organ that it has spread to.

For instance, if you have been diagnosed with colorectal liver metastasis (again, primary colon cancer that has spread to your liver), your treatment plan will include options for treating primary colon cancer rather than primary liver cancer.

This is the reason why determining whether a cancer is primary or secondary is so important. 

Treatment options differ for each type of cancer and your health is reliant upon receiving the proper cancer treatment.


What to Do When the Primary Cancer is Unknown

There are some instances when a primary cancer cannot be determined, even when you clearly have a secondary liver cancer diagnosis.  If your Baltimore liver cancer physician truly cannot figure out the primary cancer source, it will be referred to as cancer of unknown primary (CUP).

There are many reasons why a primary cancer cannot be determined:


  • It is too small to be picked up on scans
  • It is hidden by larger, secondary cancers
  • It may have dissolved even though it has metastasized
  • It may have passed from the body (as in the case of bowel cancer)


There are five different types of CUP, all of which exhibit their own specific characteristics:

  • Adenocarcinomas – These develop from gland cells that line or cover certain organs. They are most likely from the lungs, pancreas, bowel, kidneys, liver, stomach, ovaries, womb, and breasts.
  • Poorly differentiated carcinomas – These cells look relatively different from normal cells and are difficult to match as being a specific cancer type.
  • Squamous cell cancers – Developing from flat cells, these cancers are typically found on the surface of the skin or in the lining of the internal surfaces of the body. They usually start in the lungs, skin, head, neck, and cervix.
  • Neuroendocrine carcinomas – These consist of specialized nerve cells that produce hormones.
  • Undifferentiated neoplasms – These cells look completely different from normal cells and are impossible to match with a specific cancer type.

Even though evaluating individual cancer cells should reveal the type of primary cancer it is, sometimes this is not the case.

Abnormal cells can be hard to identify.

Moreover, some of the cells will appear similar to many types of cancer thus making an exact identity difficult.  However, depending on certain traits the cells exhibit, your liver specialist may be able to estimate the location of the primary cancer in order to develop an effective treatment plan.

If you or a loved one find yourselves facing either primary or secondary liver cancer and are in the Baltimore area, contact Dr. Fraiman and his multidisciplinary team of specialists today.  With over two decades of experience in the treating liver disease, Dr. Fraiman has the expertise and knowledge required to treat those with liver cancer effectively.