If a person is suspected to have Soft Tissue Sarcoma based on signs and symptoms, certain investigations are required to confirm the diagnosis of the disease and in determining the stage of disease, which in turn helps in selecting an appropriate treatment plan.
Sarcoma Committee of the Children’s Oncology Group prescribed system is mostly used for assigning a stage, clinical group, and risk group to Rhabdomyosarcoma.
What is the TNM Staging of Rhabdomyosarcoma?
TNM system is used for assigning a stage to RMS. “T” stands for “Tumor Size” and invasiveness, “N” for “Lymph Nodes”, and “M” for “Metastasis”. Numbers and/or letters after T (1, 1a, 1b, 2, 2a, and 2b), N (0 and 1), and M (0 and 1) provide more details about each of these factors.
Additionally, the sites of RMS are grouped into favorable (F) and unfavorable (UF) based on the prognosis of disease at different sites. Favorable sites include Orbit (eyeball); head and neck area except the para-meningeal area (nasal passages and nearby sinuses, middle ear, and the uppermost part of the pharynx); genitourinary tract except the kidney, bladder, and prostate; and the biliary duct. All other sites are considered as unfavorable.
T1 – Confined to the anatomic site of origin
a – </= 5 cm in maximum diameter
b – > 5 cm in maximum diameter
T2 – Extension and/or fixity to surrounding structures
a – </= 5 cm in maximum diameter
b – > 5 cm in maximum diameter
N0 – No spread of the tumor to regional lymph nodes
N1 – Regional lymph nodes involved by tumor
M0 – No spread of the tumor to distant sites
M1 – Tumor spread to non-regional nodes or distant sites
What are the 4 Stages of Rhabdomyosarcoma?
Once T, N, and M categories and the site of a tumor are determined through different diagnostic techniques, this information is combined to assign an overall stage (from 0 to IV) to the disease.
F; Any T, Any N, M0
The primary tumor is present at a favorable site, which may be of any size. It may or may not have invaded into a nearby tissue and/or spread to nearby lymph nodes, but has not spread to distant body parts.
UF; T1a-2a N0 M0
The primary tumor is present at an unfavorable site, which is </=5 cm in size. It may or may not have invaded into a nearby tissue, but has not spread to nearby lymph nodes. No spread to distant body parts.
UF; T1a-2a N1 M0
The primary tumor is present at an unfavorable site, which is </=5 cm in size. It may or may not have invaded into a nearby tissue, but has spread to nearby lymph nodes. No spread to distant body parts.
UF; T1b-2b N0 M0
The primary tumor is present at an unfavorable site, which is >5 cm in size. It may or may not have invaded into a nearby tissue and/or spread to nearby lymph nodes. No spread to distant body parts.
Any site; Any T Any N M1
The primary tumor is present at a favorable or an unfavorable site. It may be of any size. It may or may not have invaded into a nearby tissue and/or spread to nearby lymph nodes. It has spread to distant body parts, like the lungs, liver, bones, or bone marrow.
What is Clinical Stage Grouping of Rhabdomyosarcoma?
Based on the extent of the disease and the extent of primary surgical/biopsy excision, RMS is assigned a clinical group as described in the following table:
A localized tumor that has been completely removed by surgery/biopsy with negative/clear margins and no sign of lymph node involvement (no cancer left behind).
A localized tumor that has been completely removed by surgery/biopsy with a microscopic positive margin and/or sign of lymph node involvement (minor cancer left behind).
A localized tumor that was not completely removed by surgery/biopsy with a positive margin. Sign of lymph node involvement may be present but no sign of disease spread to distant body parts.
The diagnosis has revealed the spread of disease to distant body parts or presence of cancer cells in the cerebral spinal fluid, pleural, or peritoneal fluids.
How is Risk Stratification of Rhabdomyosarcoma done?
Based on the overall stage, clinical group, and type of RMS (embryonal or alveolar), a risk group is assigned to the disease. Risk group helps in selecting appropriate treatment for the disease.
Embryonal RMS; TNM stage 1; and Clinical groups I, II, or III, OR
Embryonal RMS; TNM stage 2 or 3; and Clinical groups I or II
Embryonal RMS; TNM stage 2 or 3; and Clinical group III OR
Alveolar RMS; TNM stage 1, 2, or 3; and Clinical groups I, II, or III
Embryonal/Alveolar RMS; TNM stage 4; and Clinical group IV
What is the Survival according to Stage of Rhabdomyosarcoma?
Survival rates give you an idea of percentage of people that are alive 5 years after being diagnosed with rhabdomyosarcoma. It does not tell how long they live, but helps in better understanding of the treatment response. Also, what needs to be understood is that these survival rates are an average of the patients with same type and stage of cancer, that are compared to general population without the disease.
It is calculated based on whether the disease is Low Risk, Intermediate Risk or High Risk.
- 5 year survival 70-90%
- It may vary with tumor location, stage and other factors. Most of the patients are usually cured.
- 5 year survival 50-70%
- It varies with tumor location, stage and age. Children 1 to 9 years of age usually do better than younger or older ones.
- 5 year survival 20-30%
- It varies with tumor location, age of patient and type of tumor. Children 1-9 years of age, with limited spread and/or embryonal variant usually do better.
What is the Stagewise Treatment of Rhabdomyosarcoma?
Pleomorphic RMSs are usually treated with a treatment approach similar to that for other STSs. For the treatment of embryonal and alveolar RMS, patients should refer to institutions with experience in treating RMS.
All children and adults with RMS are treated with a multimodality treatment approach. Chemotherapy, surgery and/or radiotherapy is usually the part of the multimodality treatment approach. The surgery may be performed before chemotherapy, if possible, without any significant functional disability or other major cosmetic issues.
Otherwise, chemotherapy and/or radiotherapy are employed as first-line treatment. In case of the sufficient shrinkage in the tumor to render it resectable, surgery may be employed to remove all cancerous tissue. All these treatments may be employed separately or in combination when the tumor continues to grow or comes back after the initial treatment.
This may help in improving the overall quality of life by providing relief from the symptoms caused by the RMS. They are generally given as supportive care for advanced stage cancer. These include but are not limited to using drugs to reduce pain and other symptoms such as vomiting, fatigue or external-beam radiation therapy for bleeding or pain, etc.