Cancer and cell types

It is important for doctors to know what type of cancer a person has. The type of cancer is usually based on two things:

  • the area of the body where the cancer first started
  • the type of cell where it first developed.

The most common areas for cancer to develop are the:

  • breast
  • prostate
  • lung
  • colon and rectum (large bowel)
  • skin.

Some common cells in the body are:

  • Epithelial cells – Cancers that develop in this type of cell are called carcinomas.
  • Cells of the blood and lymphatic system – Cancers that develop in this type of cell are called blood cancers.
  • Connective tissue cells – Cancers that develop in this type of cell are called sarcomas.

Cancer can sometimes develop in other types of cell, but this is rare.

Types of cancer

Tests and scans are used to help doctors find out what type of cancer you may have. It is important for them to know this because different cancer types can behave and respond to treatment differently.

It is possible to diagnose many cancers early. Different treatments are now available for people who are diagnosed with cancer. Even if it is not possible to cure the cancer, treatment can sometimes help control it for months or years.

Cancers are described by:

  • site – the area of the body where the cancer first started (the primary site)
  • cell type – the type of cell the cancer started from.


Cancer types by site

Most cancer types are described by where the cancer starts in the body (the primary site). The most common sites for cancer to develop in include the:

  • breast
  • prostate
  • lung
  • colon and rectum (large bowel)
  • skin.


Cancer and cell types

Cancer can be described by the type of cell it started from. The cell that a cancer starts from can affect how the cancer behaves and responds to treatment.

Cells

The body is made up of millions of cells. These cells make up all our tissues and organs. There are different types of cells, which have different roles in the body. Some cells are very common and are in almost all the organs in the body. Other cells are only found in one part of the body, such as brain cells.

Here are some common cells in the body:

  • Epithelial cells – These cells cover the outside of the body as skin. They also form the tissues that line the inside of our bodies and cover our organs.
  • Cells of the blood and lymphatic system – These cells are in our blood, the bone marrow (where blood cells are made) and in the lymphatic system (which fights infection).
  • Connective tissue cells – These cells are in the supportive and connective tissues in the body. These include the muscles, bones, joints and fatty tissue.

Cancers that start in each of these cell types have different names.

Carcinomas

Cancers that start in epithelial cells (see above) are called carcinomas. They are the most common type of cancer in adults. Most lung, breast, prostate and bowel cancers are carcinomas.

There are different types of epithelial cells:

  • Squamous cells – These cells are found in the skin. They also cover the surface of many parts of the body. These include the mouth, gullet (oesophagus) and the airways.
  • Glandular (adeno) cells – These cells form the lining of all the glands in the body. These include those in the breast, lung, bowel, stomach, ovaries and prostate.
  • Urothelial (transitional) cells – These cells line the bladder and parts of the urinary system.
  • Basal cells – These cells are found in the skin.

Carcinomas may start in any of these cell types.

Blood cancers

Cancers that start in the blood or bone marrow (where blood cells are made) are called leukaemias.

Plasma cells are a type of white blood cell found in the bone marrow. Cancer that starts in a plasma cell is called myeloma.

Cancers that start in the lymphatic system (which helps the body fight infection) are called lymphomas.

Sarcomas

Cancers that start in connective tissue cells are called sarcomas.

Sarcomas are rare. They can be split into two main types:

  • bone sarcomas – these start in the bones
  • soft tissue sarcomas – these affect the tissues which support and protect the body’s organs, such as the muscles or fatty tissue.

Cancers that start in other types of cells

Cancer can develop in other types of cells. These cancers include:

Back to Understanding thyroid cancer

Signs and symptoms

A painless lump in the neck is the most common symptom of thyroid cancer, but there are others to watch out for.

What is cancer?

Cancer is a disease of our cells. Sometimes cells go wrong and become abnormal. They keep dividing to make more abnormal cells which form a lump or tumour.

The thyroid gland

The thyroid gland releases important hormones that keep your body functioning at the correct speed.

Why do cancers come back?

Sometimes, tiny cancer cells are left behind after cancer treatment. These can divide to form a new tumour.