What are sarcomas and carcinomas?

Carcinomas and sarcomas are two of the main types of cancer.

Carcinomas are cancers that develop in epithelial cells, which cover the internal organs and outer surfaces of your body. Sarcomas are cancers that develop in mesenchymal cells, which make up both your bones and soft tissues, such as muscles, tendons, and blood vessels.

Cancer happens when cells start to divide uncontrollably and spread to other tissues. This creates masses called tumors. Most cases of cancer involve either a carcinoma or a sarcoma. There are three other main types of cancer:

  • Lymphomas. These affect cells in your lymph nodes.
  • Myelomas. These affect plasma cells in your bone marrow.
  • Leukemias. These affect bone marrow cells.

The main difference between carcinomas and sarcomas is where they originate.


Carcinomas, which originate in epithelial cells, tend to affect your skin or mucous membranes. The five most common types of carcinoma include:

  • Adenocarcinoma. This type of carcinoma affects organs that produce fluids or mucous, such as the breasts or prostate.
  • Basal cell carcinoma. This type affects the cells that form the foundation of your outer-most layer of skin. This is the most common type of skin cancer.
  • Squamous cell carcinoma. This type affects the cells above the basal cells in your skin and is the second most common type of skin cancer.
  • Transitional cell carcinoma. This type affects transitional cells in your urinary tract, including your bladder, kidneys, and ureter.


Sarcomas are tumors that develop from soft tissue cells called mesenchymal cells. Mesenchymal cells help form and support many vital organs and tissues, such as:

  • bones
  • blood vessels
  • cartilage
  • nerves
  • muscles
  • fat
  • joints
  • tendons
  • ligaments

While rare, there are over 75 types of sarcomas. They can occur anywhere, but are most common in the abdomen, arms, or legs.

The most common types of sarcoma include:

  • Undifferentiated pleomorphic sarcoma. This type of sarcoma involves soft tissue and bone cells at the same time.
  • Leiomyosarcoma. This type of sarcoma involves smooth muscle cells that line your blood vessels, gastrointestinal tract, and uterus.
  • Osteosarcoma. This type of sarcoma involves bone cells.
  • Liposarcoma. This type of sarcoma involves fat cells.

Carcinomas and sarcomas also differ in how common they are. While carcinomas are more common, sarcomas are rarer.


About 90 percent of all cancers cases involve a type of carcinoma.

Carcinomas affect people of all ages, genders, and ethnicities. There are different risk factors for different carcinomas. Some of these risk factors include:

  • smoking
  • excessive alcohol consumption
  • long-term exposure to ultraviolet light from the sun or tanning beds
  • long-term exposure to heavily polluted air
  • obesity
  • inactivity or lack of physical fitness
  • being fair skinned


According to Cancer Research UK, sarcomas account for less than 1 percent of cancers diagnosed each year.

Like carcinomas, sarcomas can affect anyone. However, certain medical conditions, environmental influences, and lifestyle habits can increase your risk of developing a type of sarcoma.

Medical risk factors for sarcomas include:

Environmental and lifestyle risk factors for sarcoma include:

  • exposure to harmful or toxic chemicals, especially arsenic, thorium dioxide, and vinyl chloride
  • exposure to radiation during cancer therapy
  • exposure to repeated radiation from continual or frequent diagnostic imaging scans, like X-rays

In addition, some types of sarcomas are more common in certain age groups.

Types of sarcomas that are more common in infants, children, and young adults include:

Types of sarcomas that are more common in adults include:

  • adult fibrosarcoma
  • fibromyxoid sarcoma, low-grade
  • liposarcomas
  • myxofibrosarcomas, low-grade

It’s very hard to say whether carcinomas or sarcomas are more dangerous. Survival rates for any type of cancer depend on a variety of factors, including:

  • size of the tumor
  • location of the tumor
  • growth rate of the tumor or cancerous cells
  • whether the cancer has spread to other tissues or organs
  • how many times the cancer has returned after treatment
  • overall health
  • age
  • additional medical conditions
  • gender
  • ethnicity

Your doctor can give you a better idea of your prognosis based on these factors.

Carcinomas and sarcomas are two of the main types of cancer. While they sound similar, they affect different parts of the body. Carcinomas are the most common type of cancer, while sarcomas are relatively rare.