Endometrial Cancer Stages

After a woman is diagnosed with endometrial cancer, doctors will try to figure out if it has spread and, if so, how far. This process is called staging. The stage of a cancer describes the amount of cancer in the body. It helps determine how serious the cancer is and how best to treat it. The stage is one of the most important factors in deciding how to treat the cancer and determining how successful the treatment might be.

Endometrial cancer stages range from stage I (1) through IV (4). As a rule, the lower the number, the less the cancer has spread. A higher number, such as stage IV, means cancer has spread to other parts of the body. And within a stage, an earlier letter means a lower stage. Although each person’s cancer is unique, cancers with similar stages tend to have a similar outlook and are often treated in much the same way.

How is the stage determined?

The 2 systems used for staging endometrial cancer, the FIGO (International Federation of Gynecology and Obstetrics) system and the American Joint Committee on Cancer TNM staging system are basically the same.

They both stage (classify) this cancer based on 3 factors:

• The extent (size) of the tumor (T): How far has the cancer grown into the uterus? Has the cancer reached nearby structures or organs?
• The spread to nearby lymph nodes (N): Has the cancer spread to the para-aortic lymph nodes? These are the lymph nodes in the pelvis or around the aorta (the main artery that runs from the heart down the back of the abdomen and pelvis).
• The spread (metastasis) to distant sites (M): Has the cancer spread to distant lymph nodes or distant organs in other parts of the body?

Numbers or letters after T, N, and M provide more details about each of these factors. Higher numbers mean the cancer is more advanced. Once a person’s T, N, and M categories have been determined, this information is combined in a process called stage grouping to assign an overall stage.

The staging system in the table below uses the pathologic stage. It's found by examining tissue removed during an operation. This is also known as surgical staging. Sometimes, if surgery isn't possible right away, the cancer will be given a clinical stage instead. This is based on the results of a physical exam, biopsy, and imaging tests done before surgery. For more details, see Cancer Staging.

The system described below is the most recent AJCC system. It went into effect January 2018.

Endometrial cancer staging can be complex, so ask your doctor to explain it to you in a way you understand.

Stage	Stage grouping	FIGO Stage	Stage description*
I	T1 N0 M0	I	The cancer is growing inside the uterus. It may also be growing into the glands of the cervix, but not into the supporting connective tissue of the cervix (T1). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
IA	T1a N0 M0	IA	The cancer is in the endometrium (inner lining of the uterus) and may have grown less than halfway through the underlying muscle layer of the uterus (the myometrium) (T1a). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
IB	T1b N0 M0	IB	The cancer has grown from the endometrium into the myometrium. It has grown more than halfway through the myometrium, but has not spread beyond the body of the uterus (T1b). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
II	T2 N0 M0	II	The cancer has spread from the body of the uterus and is growing into the supporting connective tissue of the cervix (called the cervical stroma). But it has not spread outside the uterus (T2). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
III	T3 N0 M0	III	The cancer has spread outside the uterus, but has not spread to the inner lining of the rectum or urinary bladder (T3). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
IIIA	T3a N0 M0	IIIA	The cancer has spread to the outer surface of the uterus (called the serosa) and/or to the fallopian tubes or ovaries (the adnexa) (T3a). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
IIIB	T3b N0 M0	IIIB	The cancer has spread to the vagina or to the tissues around the uterus (the parametrium) (T3b). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
IIIC1	T1-T3 N1, N1mi or N1a M0	IIIC1	The cancer is growing in the body of the uterus. It may have spread to some nearby tissues, but is not growing into the inside of the bladder or rectum (T1 to T3). It has also spread to pelvic lymph nodes (N1, N1mi, or N1a), but not to lymph nodes around the aorta or distant sites (M0).
IIIC2	T1-T3 N2, N2mi or N2a M0	IIIC2	The cancer is growing in the body of the uterus. It may have spread to some nearby tissues, but is not growing into the inside of the bladder or rectum (T1 to T3). It has also spread to lymph nodes around the aorta (para-aortic lymph nodes) (N2, N2mi, or N2a), but not to distant sites (M0).
IVA	T4 Any N M0		The cancer has spread to the inner lining of the rectum or urinary bladder (called the mucosa) (T4). It may or may not have spread to nearby lymph nodes (Any N), but has not spread to distant sites (M0).
IVB	Any T Any N M1	IVB	The cancer has spread to inguinal (groin) lymph nodes, the upper abdomen, the omentum, or to organs away from the uterus, such as the lungs, liver, or bones (M1). The cancer can be any size (Any T) and it might or might not have spread to other lymph nodes (Any N).

*The following additional categories are not listed on the table above:

• TX: Main tumor cannot be assessed due to lack of information.
• T0: No evidence of a primary tumor.
• NX: Regional lymph nodes cannot be assessed due to lack of information.