Types and grades of stomach cancer

The type of stomach cancer you have depends on what type of cell it started in. The most common type of stomach cancer is called adenocarcinoma. 

The grade means how abnormal the cells look under a microscope.

Knowing the type and grade helps your doctor decide which treatment you need.

Types of stomach cancer

Adenocarcinoma 

Adenocarcinomas are cancers that develop in gland cells. These cells make mucus and stomach juices.

This is the most common type of stomach cancer in the UK.

Linitis plastica is a rare type of adenocarcinoma.  It spreads to the muscles of the stomach wall. This thickens the stomach wall and affects digestion.

Rare types of stomach cancer

The information in our stomach cancer section is about the staging and treatment of adenocarcinoma.

Treatment and staging for rare types of stomach cancer depends on what type of cell the cancer starts in. 

Squamous cell cancer

These cancers develop in squamous cells. These are the flat cells covering the lining of the stomach. Squamous cell cancer is treated in the same way as adenocarcinoma.

Non-Hodgkin lymphoma

Non-Hodgkin lymphoma is a cancer of the lymphatic system. The treatment is different to other stomach cancers. 

Gastrointestinal stromal tumour (GIST)

This is a rare type of sarcoma found in the digestive system, most often in the wall of the stomach.

Neuroendocrine tumours

Stomach neuroendocrine tumours (NETs) are rare stomach tumours. They start in the neuroendocrine cells of the stomach. You might hear some stomach NETs called carcinoid tumours.

Grades of stomach cancer

The grade means how abnormal the cells look under a microscope. Knowing the grade gives your doctor an idea of how the cancer might behave and what treatment you need.

The grades of cancer cells are from 1 to 3:

• grade 1 (low grade) look like normal stomach cells
• grade 2 look a bit like normal cells
• grade 3 (high grade) look very abnormal and not like normal cells

Differentiation

As normal cells grow and mature, they become specialised for their role and place in the body. This is called differentiation. 

This means that your grade of cancer may be described as:

• well differentiated
• moderately differentiated
• poorly differentiated

Cancer cells can look very like normal cells. When they are you might hear your doctor describe them as well differentiated or low grade. These cancers are more likely to grow slowly.

If the cancer cells look underdeveloped and nothing like a normal cell, they are known as poorly differentiated or high grade. These cancers tend to grow and spread more quickly than low grade cancers.