How is testicular cancer staged?
The TNM staging system
A staging system is a standard way for your cancer care team to sum up the extent of your cancer. Testicular cancer is staged using the TNM system created by the American Joint Committee on Cancer (AJCC). It’s based on 4 key pieces of information:- T refers to how much the main (primary) tumor has spread to tissues next to the testicle.
- N describes how much the cancer has spread to regional (nearby) lymph nodes.
- M indicates whether the cancer has metastasized (spread to distant lymph nodes or other organs of the body).
- S indicates the serum (blood) levels of tumor markers that are made by some testicular cancers.
There are also two different types of staging in testicular cancer: clinical staging and pathological staging. In clinical staging, the stage is based on a physical examination or x-rays, CT scans, and other imaging tests. In pathological staging, the stage is based on evaluating tissue under a microscope after it has been removed during surgery. For example, clinical stage II testicular cancer means that the retroperitoneal lymph nodes are enlarged when viewed with a CT or MRI scan. Whereas, pathological stage II testicular cancer means that cancer has been found when tissue removed from the retroperitoneal lymph nodes is examined under a microscope. Pathological staging is more accurate than clinical staging, but it is not always necessary.
Here are more details on each part of the TNM system for testicular cancer:
• Primary tumor (T)
Using the TNM system, the "T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Some stages are also divided into smaller groups that help describe the tumor in even more detail. For testicular cancer, the T stage can only be determined when tissue removed during surgery is examined under a microscope. This means that the T stage is only determined after the testicle is removed, and the T stage is always a pathological stage and never a clinical stage. The “p” before the T stage indicates that it is a pathological stage. Specific tumor stage information is below.
↠ TX: The primary tumor cannot be assessed
↠ T0: There is no evidence of primary tumor
↠ Tis: Carcinoma in situ (non-invasive cancer cells)
↠ T1: The tumor has not spread beyond the testicle and epididymis (the tubes next to the testicles where sperm mature). The cancer has not reached nearby blood vessels or lymph vessels. The cancer might have grown through the inner layer surrounding the testicle (tunica albuginea), but it has not reached the outer layer covering the testicle (tunica vaginalis).
↠ T2: Similar to T1 except that the cancer has spread to blood or lymph vessels near the tumor, or the tunica vaginalis
↠ T3: The tumor is growing into the spermatic cord (which contains blood vessels, lymph vessels, nerves, and the vas deferens)
↠ T4: The tumor is growing into the skin surrounding the testicles (scrotum)
• Regional lymph nodes (N)
The “N” in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph is a fluid that flows from the different tissues and organs of the body and eventually drains into the blood stream. It passes through specialized tubes called lymphatic vessels and is filtered along the way by the lymph nodes. Cancer cells often buildup and grow in lymph nodes before they spread to other parts of the body. The first place the lymphatic fluid from the testicles drains is the retroperitoneal lymph nodes located in the retroperitoneum. These are called the regional lymph nodes for testicular cancer. Lymph nodes in the pelvis, chest, or other parts of the body are called distant lymph nodes.
In men with testicular cancer, lymph nodes usually are not biopsied or removed. Instead, the “N” stage is most often estimated by using CT scans. Lymph node stage (N stage) that is based on CT scans is the clinical stage and N stage based on a biopsy or removal of the lymph nodes is the pathological stage. When a stage has been determined pathologically, the letter “p” is added as the first letter of the stage (for example pN1).
↠ NX: Regional (nearby) lymph nodes cannot be assessed
↠ N0: No spread to regional lymph nodes is seen on imaging tests
↠ N1: There is spread to at least one lymph node, but no lymph node is larger than 2 cm (about ¾ inch) across
↠ N2: There is spread to at least one lymph node that is larger than 2 cm but is not bigger than 5 cm (2 inches) across
↠ N3: There is spread to at least one lymph node that is larger than 5 cm across
If the lymph nodes were taken out during surgery, there is a slightly different classification:
↠ pNX: Regional (nearby) lymph nodes cannot be assessed
↠ pN0: There is no spread to regional lymph nodes
↠ pN1: There is spread to 1 to 5 lymph nodes, with no lymph node larger than 2 cm (about ¾ inch) across
↠ pN2: There is spread to at least one lymph node that is bigger than 2 cm but not larger than 5 cm across; OR spread to more than 5 lymph nodes that aren’t bigger than 5 cm; OR the cancer is growing out the side of a lymph node
↠ pN3: There is spread to at least one lymph node that is bigger than 5 cm across
• Distant metastasis (M)
The "M" in the TNM system indicates whether the cancer has spread to other parts of the body. When testicular cancer spreads, it most commonly spreads to the lung and the lymph nodes of the chest, pelvis, and the base of the neck. More advanced stages may have spread to the liver and bones. Testicular cancer rarely spreads to the brain unless the primary tumor is a choriocarcinoma.
↠ M0: There is no distant metastasis (no spread to lymph nodes outside the area of the tumor or other organs, such as the lungs)
↠ M1: Distant metastasis is present
- M1a: The tumor has metastasized to distant lymph nodes or to the lung
- M1b: The tumor has metastasized to other organs, such as the liver, brain, or bone
Serum tumor markers also help to stage testicular cancer. As noted in the Diagnosis section, blood tests for tumor markers will be done before and after surgical removal of the testicle(s). Tumor markers usually decrease after the surgery. Generally, the levels need to be tested until they stop decreasing or begin to rise to determine the correct S stage. For patients who will receive chemotherapy, the tumor marker levels on the first day of chemotherapy are used to determine the patient’s risk group.
↠ SX: Tumor marker levels are not available, or the tests have not been done.
↠ S0: Tumor marker levels are normal.
↠ S1: At least one tumor marker level is above normal. This means that LDH is less than 1.5 times the upper limit of the normal range, beta-hCG is less than 5,000 mIu/mL, and AFP is less than 1,000 ng/mL.
↠ S2: At least one tumor marker level is substantially above normal. This means that LDH is 1.5 to 10 times the upper limit of the normal range, beta-hCG is 5,000 to 50,000 mIu/mL, or AFP is 1,000 to 10,000 ng/mL, and none of the tumor markers is elevated high enough to qualify as S3 (see below).
↠ S3: One or more tumor marker level is very highly elevated. This means that LDH is more than 10 times the upper limit of the normal range, beta-hCG is more than 50,000 mIu/mL, or AFP is more than 10,000 ng/mL.
Testicular Cancer Stage Grouping
Doctors assign the stage of the testis cancer by combining the T, N, and M classifications and the S level information.• Stage 0 (Carcinoma in Situ): In stage 0, abnormal cells are found in the tiny tubules where the sperm cells begin to develop. These abnormal cells may become cancer and spread into nearby normal tissue. All tumor marker levels are normal. Stage 0 is also called carcinoma in situ.
• Stage I: Cancer is at any T level, and there is no evidence of spread to either lymph nodes or other organs. Serum tumor marker levels have not been done or are not available (any T, N0, M0, SX).
• Stage IA: Cancer is in the testicle and may have grown into the rete testis and the epididymis, but it has not grown into the lymphatic or blood vessels in the testis or spread to lymph nodes or distant sites. The tumor in the testis may have grown into the inner membrane surrounding the testis, called the tunica albuginea, but not the outer membrane, called the tunica vaginalis. Serum markers are normal (pT1, N0, M0, S0).
• Stage IB: The testicular tumor has grown into the tunica vaginalis, the blood or lymphatic vessels within the testicle, the spermatic cord, or the scrotum. The cancer has not spread to lymph nodes or distant sites. Serum markers are normal (pT2, pT3, or pT4, and N0, M0, S0).
• Stage IS: Cancer is of any T stage and has not spread to lymph nodes or distant sites. Serum markers remain above normal levels after the cancerous testicle has been removed (any T, N0, M0, and S1-3). Stage IS non-seminoma testicular cancer is treated the same as stage III testicular cancer.
• Stage II: The cancer has spread to any number of regional lymph nodes but not to lymph nodes in other parts of the body or distant organs. Serum markers are unavailable (any T, N1-3, M0, SX).
• Stage IIA: Cancer has spread to retroperitoneal lymph nodes, either clinical or pathological stage N1, but none is larger than 2 cm and, if a lymph node dissection has been done, no more than five lymph nodes contain cancer. In addition, serum tumor markers are at normal levels or slightly high, and there are no signs of cancer having spread anywhere other than the retroperitoneum (any T, N1, M0, S0 or S1).
• Stage IIB: Cancer has spread to lymph nodes in the retroperitoneum, at least one of which is bigger than 2 cm but not bigger than 5 cm; or, if a lymph node dissection has been done, cancer has spread to at least one lymph node (or lymph node mass) between 2 cm and 5 cm or to more than five lymph nodes, none more than 5 cm. Serum markers are at normal levels or slightly high, and there is no evidence of cancer having spread anywhere other than the retroperitoneum (any T, N2, M0, S0 or S1).
• Stage IIC: Cancer has spread to at least one lymph node (or lymph node mass) that is larger than 5 cm. Serum markers are at normal levels or slightly high and there is no evidence of cancer having spread anywhere other than the retroperitoneum (any T, N3, M0, S0 or S1).
• Stage III: Cancer has spread to distant lymph nodes or to any organ, and serum tumor marker levels are unknown (any T, N0-3, M1, SX).
• Stage IIIA: Cancer has spread to distant lymph nodes or the lungs. Serum markers are at normal levels or slightly high (any T, N0-3, M1a, S0 or S1).
• Stage IIIB: Cancer has spread to any lymph nodes and/or the lungs but not to any other organs. Serum markers are at substantially and persistently high levels (any T, N1-3, M0, S2; or any T, N0-3, M1a, S2).
• Stage IIIC: Either or both of the following:
- Serum marker levels are highly high, and the cancer has spread to at least one lymph node or organ (any T, N1-3, M0, S3; or any T, N0-3, M1a, S3).
- The cancer has spread to an organ other than the lungs (any T, any N, M1b, any S).
Recurrent: Recurrent cancer means that the cancer has come back (recurred) after treatment. Testicular cancer can recur in the testicle (if it was not removed during surgery) or in another part of the body. If there is a recurrence, the testicular cancer may need to be staged again (called re-staging).