Grades and Stages of Neuroendocrine Tumors (NETs)

Medically Reviewed by Jennifer Robinson, MD on June 20, 2024
5 min read

When you and your doctor make a plan to treat your neuroendocrine tumor (NET), a key part of the strategy is figuring out whether your NET is advanced or just starting. To do that, you'll need to understand two important words: stage and grade.

The stage tells whether your disease has spread from its original spot, and where in your body it's moved to.

The grade describes how it looks under a microscope compared to normal cells. That's important because it can show whether it's likely to spread slowly or quickly.

There are many different types of NETs, and doctors have come up with a separate system of staging for each one.

The stages for this type are the same as the ones for pancreatic cancer. It's based on where your tumor is located.

Stage 0. It's only in the top layers of the duct cells of the pancreas -- a gland in your belly -- and not any deeper.

Stage I. It's just in the pancreas -- not in the lymph nodes or other sites. 

Stage II. It's now growing outside of the pancreas, but not in major blood vessels or nerves. 

Stage III. It's moved outside of the pancreas and into the major blood vessels and nerves.

Stage IV.  Your cancer has spread to other parts of your body.

Four categories simplify the staging system and help with decisions about whether surgery can be done to remove the pancreatic NET. You may hear your doctor use these words to describe them:

Resectable. This means you may be able to get an operation to take out the tumor, since it's mainly or entirely in your pancreas.

Borderline resectable. You may need chemotherapy or radiation to shrink the tumor before your doctor can remove it with surgery.

Locally advanced. Your cancer has moved into veins or organs near your pancreas, but hasn't spread to organs in other parts of your body. Doctors can't remove the tumor in an operation.

Metastatic. Your cancer has spread to organs like your liver or stomach, and surgery isn't an option to remove it.

They show up in your lungs or an area called the GI tract, which includes your stomach, intestines, colon, and rectum.

If you have GI carcinoid tumors, your doctor may discuss three stages:

Localized. Your cancer hasn't spread outside the place where it started, such as your stomach, intestine, or colon.

Regional spread. The tumors have moved to the lymph nodes, small glands found around the body. It may also have spread to other nearby tissues, such as fat or muscle.

Distant spread. The cancer has spread to other parts of your body, like the liver, bones, or lungs.

Lung carcinoid tumors are staged in the same way as non-small cell lung cancer, and it's based on where the cancer has spread.

Stage 0. The tumor is only in the top layers of cells lining the airways.

Stage I. It's only in your lungs. It hasn't spread into the lymph nodes. 

Stage II. The cancer is in the lung and is typically a few centimeters (cm) in size, but smaller than about 3 inches.. It may or may not have spread to the lymph nodes on the same side of the chest where the tumor started. 

Stage III. It's in the lung and lymph nodes in the middle of the chest. The tumor might also have spread in the chest, including the heart, chest wall, and collar bones.

Stage IV. The cancer may have spread to both lungs, the fluid around the lungs, and other organs.

Merkel cell carcinoma is a type of skin cancer. It has five main stages, which include information about how large your tumor has grown:

Stage 0. It's only in the outermost layer of the skin.

Stage I. The main tumor is no more than 2 cm across in its widest place. It hasn't spread to the lymph nodes or any other part of your body.

Stage IIA and IIB. Your tumor is bigger than 2 cm. It hasn't spread to lymph nodes, but may have spread to muscle, bone, or cartilage. 

Stage IIC. It's grown into the muscle, bone, or cartilage, but not lymph nodes.

Stage III. Your tumor has spread to lymph nodes and may also be in tissue that's near the original spot.

Stage IV. The cancer has moved to other parts of your body, such as the liver, lungs, bones, or brain.

Three stages are used for this tumor of the adrenal glands, which are located at the top of your kidneys:

Localized. Your tumor is in one or both adrenal glands.

Regional. The cancer has spread to nearby lymph nodes or other tissues close to where the tumor started.

Metastatic. The disease has spread to other parts of your body, such as the liver, lungs, or bone.

Your doctor will do a biopsy, a procedure to remove a piece of your tumor. Then, a specialist will look at its cells under a microscope and give the tumor a grade based on how it looks compared to healthy cells:

A low-grade tumor looks a lot like normal cells. Your doctor may call them "well-differentiated." They often grow and spread slowly.

If you have a high-grade tumor, the cells won't look normal and may grow quickly. Your doctor might refer to them as "poorly differentiated."

After your doctor has figured out these things, you'll discuss ideas for treatment. Which one you get depends on whether your disease has spread, and what organs it affects.

Ask questions so you can understand your diagnosis. And make sure you know all the treatment options for your cancer stage and grade, so you can feel good about the choice you and your doctor make. It's OK to ask for a second opinion from another doctor.

Whether your condition is in an early stage or advanced -- keep in mind that there's more to treatment than drugs and surgery. You've also got to tend to your emotions and make sure you don't have too much pain.

Palliative care can help with this. It's something you get in addition to your regular treatment. The goal is to prevent or manage the symptoms and side effects of your disease -- and give you the support you need for any worries and anxious feelings that crop up.

A team of doctors and nurses work together to improve your quality of life. They might suggest medicine or relaxation techniques, for example, to ease your pain and help lower stress or anxiety.