Stages of rhabdomyosarcoma

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Staging describes or classifies a cancer based on how much cancer there is in the body and where it is when first diagnosed. This is often called the extent of cancer. Information from tests is used to find out the size of the tumour, which parts of the organ have cancer, whether the cancer has spread from where it first started and where the cancer has spread.

The healthcare team uses the stage to plan treatment and estimate the outcome (your child's prognosis). The stage also depends on where the tumour started and whether it's favourable or unfavourable. For rhabdomyosarcoma (RMS), the healthcare team also looks at other things like the clinical group and the risk group.

The staging system for RMS has 4 stages. Often the stages 1 to 4 are written as the Roman numerals I, II, III and IV. Generally, the higher the stage number, the larger the cancer is or the more the cancer has spread. Talk to your child's doctor if you have questions about staging.

When describing the stage, doctors may use the words local or distant. Local means that the cancer is only in the area where it started or close to it, including in nearby lymph nodes, and has not spread to other parts of the body. Distant means the cancer is in a part of the body farther from the area where the cancer started.

Find out more about staging cancer.

Where the tumour started

Where the tumour started is also called the site of the primary tumour. Doctors describe it as favourable or unfavourable. Favourable sites, or areas, usually have a better prognosis. Unfavourable areas usually have a poorer prognosis. Other things also influence the prognosis.

Favourable sites include the:

  • area around the eye (called the orbit)
  • eyelid
  • head and neck areas but not areas near the meninges (also called non-parameningeal sites)
  • gallbladder and bile ducts
  • ovaries, fallopian tubes, uterus, cervix, vagina, area next to the testicles (paratesticular), penis, ureters and urethra

Unfavourable sites include all other sites, such as the:

  • bladder
  • kidney
  • prostate
  • muscles in an arm or leg
  • area around the skull (cranium)
  • head and neck areas close to the meninges (parameningeal), including the nasal passages, paranasal sinuses, middle ear and back of the upper throat
  • muscles in the central part of the body (trunk)
  • back of the abdomen (retroperitoneum)

Stage 1

The cancer is in a favourable area. It has not spread to a part of the body farther from where it started.

Stage 2

The cancer is in an unfavourable area. The tumour is 5 cm or smaller. It has not spread to nearby lymph nodes or other parts of the body.

Stage 3

The cancer is in an unfavourable area. The tumour is 5 cm or smaller. It may have grown into surrounding areas. The cancer has spread to nearby lymph nodes.

Or

The cancer is in an unfavourable area. The tumour is larger than 5 cm. It may have grown into surrounding areas. The cancer may have spread to nearby lymph nodes.

Stage 4

The cancer is in any area and can be any size. It has spread to other parts of the body (called distant metastasis), such as to the lungs, liver or bone marrow. This is also called metastatic RMS.

Recurrent RMS

Recurrent RMS means that the cancer has come back after it has been treated. If it comes back in the same place that the cancer first started, it's called local recurrence. If it comes back in tissues or lymph nodes close to where it first started, it's called regional recurrence. It can also recur in another part of the body. This is called distant metastasis or distant recurrence.

Clinical groups

Clinical groups are assigned after surgery. They are based on whether the cancer has spread and how much of the cancer was removed during surgery. Each group is given a number from 1 to 4.

Group 1

The tumour is local. It was completely removed with surgery.

Group 2

The tumour is local. It was removed with surgery, but cancer cells were found at the area (called the margin) between the cancer and the surrounding healthy local tissue that was removed with the tumour or nearby lymph nodes or both.

Group 3

The tumour wasn't completely removed with surgery. The cancer may have spread to nearby lymph nodes but not to distant organs.

Group 4

The cancer has spread to other parts of the body, such as the lungs, liver, bones, bone marrow, distant muscles or distant lymph nodes.

Risk groups

Risk groups help the doctor estimate the outcome and plan the best treatment for children diagnosed with RMS. These risk groups are assigned by the Soft Tissue Sarcoma Committee of the Children's Oncology Group.

Risk group

Type of rhabdomyosarcoma

Stage

Clinical group

low

embryonal

1

1, 2 or 3 (orbit only)

2 1 or 2

intermediate

embryonal

1

3 (non-orbit)

2, 3 3
3 1, 2
4 4 (age younger than 10 years)

alveolar

1, 2 or 3

1, 2 or 3

high

embryonal

4

4 (age 10 years or older)

alveolar 4 4

Expert review and references

  • Paul Nathan, MD, MSc, FRCPC
  • Normand Laperriere, MD, FRCPC
  • PDQ® Pediatric Treatment Editorial Board . Childhood Rhabdomyosarcoma Treatment (PDQ®) – Patient Version . Bethesda, MD : National Cancer Institute ; 2019 : https://www.cancer.gov/.
  • PDQ® Pediatric Treatment Editorial Board . Childhood Rhabdomyosarcoma Treatment (PDQ®) – Health Professional Version . Bethesda, MD : National Cancer Institute ; 2020 : https://www.cancer.gov/.
  • Cripe TP . Medscape Reference: Pediatric Rhabdomyosarcoma. WebMD LLC; 2018: https://www.medscape.com/.
  • American Society of Clinical Oncology (ASCO). Cancer.net: Rhabdomyosarcoma - Childhood: Stages and Groups. 2018: https://www.cancer.net/.
  • Wexler LH, Skapek SX, Helman LJ. Rhabdomyosarcoma. Pizzo PA, Poplack DG, eds.. Principles and Practice of Pediatric Oncology. 7th ed. Philadelphia, PA: Wolters Kluwer; 2016: 31:798–827.
  • American Cancer Society. Rhabdomyosarcoma Early Dectection, Diagnosis, and Staging. 2018: https://www.cancer.org/.