Rhabdomyosarcoma in Children(RMS) – Symptoms, Causes, and Treatment by Dr. Stalin Ramprakash

Rhabdomyosarcoma is very commonly found in

• Orbital areas like the eye and around the eyes.
• Extremities like arms and legs. (Extremities are the farthest parts of the body).
• Genitourinary systems like the urethra, and urinary bladder.
• Reproductive systems like the testes, vagina, uterus, and very rarely ovaries.
• Other areas like the head, neck, and trunk.

Some locations are considered favorable sites (as they respond to treatment better) and other sites are unfavourable sites. For example, eye socket (orbit), paratesticular, vaginal and uterine (genitourinary but non-bladder and non-prostrate), head and neck but not arising close to meninges (the layer that covers the brain) are considered favorable sites and all the others are considered unfavorable sites.

Types of Rhabdomyosarcoma in Children

There are several types of childhood Rhabdomyosarcoma. The division is based on the occurrence of a tumor on that body part as well as their characteristic appearance under the microscope.

The most commonly occurring rhabdomyosarcomas in children are of two types, they are

1. Embryonal Rhabdomyosarcoma

This mainly occurs in genital organs, urinary organs, and head and neck parts of the body. It is the most common type of rhabdomyosarcoma seen in children and has an intermediate prognosis.

2. Alveolar Rhabdomyosarcoma

Alveolar Rhabdomyosarcoma occurs in the arms, legs, chest, and abdominal areas. It is more commonly seen in teen-aged children than in younger children. This type is generally associated with a poor prognosis.

3. Other Types

The other rarer types of Rhabdomyosarcomas such as

• Sclerosing and Spindle cell Rhabdomyosarcoma (relatively poor prognosis)
• Diffuse anaplastic Rhabdomyosarcoma

Both of these are rare in children. These commonly affect adults and adolescents and are also associated with relatively poor prognosis.

Another rarer type which characteristically occurs in infants is called Botroid and spindle cell type. It is generally associated with favorable prognosis. Alveolar type is considered an unfavorable type and all other histological subtypes such as embryonal, spindle cell and botryoid types are considered favorable types for treatment purposes.

Based on the speed at which the tumor cells are growing it is classified as a low grade or high-grade tumor. There are two grades in childhood Rhabdomyosarcoma:

• When the tumor cells look similar to normal cells and grow slowly, they are low grade and less likely to spread to the other parts of the body.
• The high-grade tumor cells look very abnormal and grow faster and are more likely to spread to other parts of the body. For example, embryonal and alveolar types are always high grade.

[Read : Aplastic Anaemia in Children]

Staging of Childhood Rhabdomyosarcoma

Staging is a process by which doctors assess the extent and spread of cancer to plan treatment and prognosticate.

There are four stages in childhood Rhabdomyosarcoma.

Stage 1: Localized and completely resected

Stage 2: Total gross resection with evidence of regional spread (microscopic residue may be present)

Stage 3: Incomplete resection (gross residue left behind)

Stage 4: Tumor has spread to distant parts of the body

With all the above information, the treating doctors will allocate any given patient into different treatment groups. The factors that doctors consider in assigning the treatment groups include

• Site of origin (favorable site Vs unfavorable site)
• Type of tumor by histopathological examination (favorable site Vs unfavorable Histopathological type)
• Age of the patient (10 years Vs more than 10 years), size of the tumor (less than 5 cm Vs > 5 cm) and staging of the tumor.

After assigning the treatment group your pediatric oncologist will discuss with you the treatment plan. Treatment will increase proportionally to the risk group. High-risk group patients receive more aggressive treatment and vice versa.

The success rate of treatment varies widely from 90% cure rate in low-risk localized diseases to under 30% for widespread high-risk diseases.

What Causes Rhabdomyosarcoma in Children?

There is no such known cause that can lead to cancer in children. The reason for the occurrence of any cancer remains idiopathic in the majority of the patients.

Some congenital defects and genetic inheritance may count as a reason for childhood rhabdomyosarcoma. Some among them are

1. Beckwith-Wiedemann Syndrome

This is a genetically inherited disorder where the children suffer from overgrowth and a tendency for low blood sugar. It can be one of the risk factors for encountering rhabdomyosarcoma in childhood.

2. Li-Fraumeni Syndrome

Another genetically inherited disorder where the children fall at high risk of contracting rare and multiple types of cancers. This can be because of the mutation in a particular gene called TP53.

3. Neurofibromatosis

Neurofibromatosis is a type of genetic disorder that is again of two types. Children with type 1 neurofibromatosis are at the risk of developing solid tumors on nerve tissues. Often associated with bladder or Prostate Rhabdomyosarcoma.

4. Noonan Syndrome

Children with Noonan Syndrome are at risk of developing Rhabdomyosarcoma because of genetic alterations and are prone for certain birth defects.

5. Dicer1 Syndrome

Dicer1 is a gene which is mutated in this rare inherited genetic condition. . The mutations in this gene lead children to fall at risk of contracting cancers and benign tumors that develop in various parts of the body including soft tissues.

6. Costello Syndrome

Costello syndrome is an inherited gene disorder. This can lead to congenital organ disorders in children thus shoving them at the risk of contracting several types of cancers, including Rhabdomyosarcoma, and often associated with short stature, developmental delay, heart problems and unusual facial appearances.

Having one of these genetic disorders doesn’t mean that your child will get cancer. It is important to understand that these are just the risk factors. Reassure your children regarding the prognosis, which can ease the journey of the diagnosis and treatment.

Signs and Symptoms of Rhabdomyosarcoma in Children

The symptoms of Rhabdomyosarcoma will depend on the location and if it has an effect on the nearby organs and structures. The symptoms of Rhabdomyosarcoma include

• Inability to pass urine or abdominal pain due to blockage to the urinary pathway.
• Blood in the urine.
• Difficulty in urinating and bowel movements.
• An unusual swelling or lump that grows rapidly or doesn’t regress.
• Crossed eyelids.
• Swelling around the eye area.

It is important to take help from your healthcare provider if you notice any of the above unusual symptoms in your child.

Having any one of the above symptoms sometimes may not necessarily be cancer. But it is vital not to ignore it and take it to the notice of a doctor. Early detection of Rhabdomyosarcoma has an excellent prognosis, and the child is more likely to get permanent remission from the disease.

How is Rhabdomyosarcoma Diagnosed in Children?

Rhabdomyosarcoma is diagnosed in a step-by-step process. Once you take your child to the doctor with any of the above symptoms, the doctor may suggest certain tests including.

1. Physical Examination

The doctor will examine your child physically for any obvious symptoms. They may also ask for the child’s medical history and enquire about any genetic disorders that run in the family.

2. X-Ray

Taking images of the body by using X-Rays. This test can help in getting detailed pictures of that particular body part.

3. CT Scan

Computed Tomography is a test that again uses X rays but in a more sophisticated manner. It assists in getting images of the areas of the body in a more detailed manner and you can visualize different organs in cross section. It provides information about abnormal growths through digital imaging. Sometimes it may be carried out by inserting a dye to get clearer pictures of the organs and tissues.

4. MRI

Magnetic Resonance Imaging or an MRI is done to find clear images of the areas inside the body. It can help the doctors to find abnormal growths or tumors inside that particular area of the body. It is also called nuclear magnetic resonance imaging.

5. PET Scan

Positron Emission Tomography or PET CT scan is a type of imaging test which helps in identifying cancer cells. Doctors insert a small amount of radioactive glucose into your child’s vein. Cancer cells tend to consume more glucose than normal cells. Using this procedure, an imaging screen displays the tumor cells brightly and is especially useful to study the extent of cancer and figure out where it has spread.

6. Bone Scan

It is one of the imaging tests which help in identifying cancer cells inside the bones. The imaging device produces pictures of the bones with the help of a radioactive material called radiopharmaceuticals inside your child’s body. These images are known as scintigrams.

7. Lumbar Puncture

Lumbar puncture is carried out for cancers that are metastatic and may have the probability of spreading to the spinal cord and brain especially if the tumor is close to the meninges. Doctors will take out the fluid by inserting a needle inside the spinal cord. Pathologists will check the collected fluid for the presence of cancer cells.

8. Bone Marrow Aspiration or Biopsy

Bone marrow biopsy provides information about whether the cancer cells have spread to the bone marrow. Doctors will insert a needle into the bone marrow to collect a certain amount of thick marrow fluid that is needed for testing.

[Read : Bone Marrow Transplant For Children]

9. Biopsy of the Tumor or Excision of the Mass

If there is an indication of Rhabdomyosarcoma in your child, doctors may suggest further tests like core needle biopsy, excision of the tumor and resection of sentinel lymph nodes to check for cancer cells. The Sentinel lymph node is the first lymph node that receives cancer cells from the initial tumor.

Pathologists work on certain procedures to find if there are any cancer cells in the tissue collected through biopsy.

How is Rhabdomyosarcoma Treated?

There are many treatment options available to cure childhood Rhabdomyosarcoma. Often these treatment options are used in combination to cure the patient of Rhabdomyosarcoma. The majority of the patients will need chemotherapy as systemic treatment plus local control of disease with surgery, radiotherapy or both.

Doctors may consider several factors before moving on to the treatment like the child’s age, medical history, genetic defects, size and location of the tumor, the appearance of the tumor and staining of the biopsy material under microscopy and respectability of the tumor based on imaging. A group of specialist doctors may sit and discuss your child’s probability of responding to the treatment by considering all the above factors. Most commonly administered treatments are

1. Surgery

Children with low-risk Rhabdomyosarcoma may require surgery to remove cancer. Surgical Oncologists can take off such low-risk tumors completely through surgery. Doctors may also suggest surgery for other stages of Rhabdomyosarcomas. However, your child may require combination treatments after the surgery if there is any unresected tumor.

Adjuvant chemotherapy is the procedure where the doctors administer chemo medications to shrink the tumor before the surgery.

2. Radiation Therapy

Doctors will induce certain high-energy radiation into your child’s body to shrink the cells of Rhabdomyosarcoma and kill them. There are two types of radiation therapies.

External radiation therapy is where the doctors follow several procedures to target the cancer cells and kill them. Doctors administer external radiation therapy through a machine that targets a particular body part affected by a tumor. There are certain procedures like proton beam therapy that can also help in avoiding the damage of any nearby healthy tissue.

Oncologists prefer internal radiation therapy to treat the Rhabdomyosarcoma of the vagina, vulva, and other internal organs like the uterus, and urinary bladder. This therapy includes the incision of needles containing radiation in that particular body part with cancer.

3. Chemotherapy

Chemotherapy works successfully in treating childhood Rhabdomyosarcomas. In this treatment, doctors administer medication intravenously, or sometimes orally. The medications used in chemotherapy are effective in killing cancer cells and this type of therapy is known as systemic chemotherapy.

Doctors prefer neoadjuvant chemotherapy to treat aggressive childhood Rhabdomyosarcoma. In this procedure, doctors will administer chemo before the surgery to shrink the tumor. This can help in saving the nearby healthy tissues from damage during the surgery.

4. Clinical Trials

Certain treatments like immunotherapy and targeted therapy are still under study and some patients may want to undergo clinical trials.

5. Immunotherapy

In this kind of treatment, doctors will prepare the child’s immunity to fight against cancer. Immunotherapy is still under clinical trials. Doctors use several procedures in immunotherapy to treat recurrent and metastatic Rhabdomyosarcomas.

6. Targeted Therapy

It is a type of treatment that focuses only on cancer cells and kills them. Healthy cells stay unaffected in this therapy. The treatment is still under study for childhood Rhabdomyosarcoma. In Targeted therapy, certain inhibitors are effective in stopping the rapid cell division of cancer cells. This therapy helps in treating recurrent Rhabdomyosarcoma.

For local control of the disease where wide excision is possible without causing significant damage to the surrounding structures surgeries is preferred. Where non-mutilating surgery is not possible, radiotherapy is preferred. Discuss with your treating doctor the various treatment options and the likelihood of a long-term cure for your child.

When to See a Doctor?

Consult a doctor immediately if you see any of the symptoms that indicate Rhabdomyosarcoma in your child. Having these symptoms does not mean that your child has cancer but taking it to the notice of the doctor can reassure you about your child’s health condition. Take your child to regular screening, if your child has any genetic predisposition to cancer. It is very important to keep in touch with your child’s pediatrician for any unusual symptoms that you notice.

It may not be easy to deal with childhood sarcomas, but with the advancement in treatments and drugs, there is a great chance of prognosis. Take the help of support groups through which you can gain information about children who are going through the same and are in remission for a long time. This can help you gain the strength to reassure your child about the success of the treatment they undergo.

FAQ’s

1. Is Rhabdomyosarcoma Common in Children?

Rhabdomyosarcoma is the most common soft tissue cancer in children. Specialist doctors can treat this type with combination treatments. The prognosis depends on the stage and the child’s medical history.

2. Can Rhabdomyosarcoma be Inherited?

Rhabdomyosarcoma can occur due to certain inherited genetic disorders that predispose children to contract soft tissue cancers.

3. What is the First Line of Treatment For Rhabdomyosarcoma?

The first line of treatment for childhood Rhabdomyosarcoma is surgery. If the resection of the tumor is not complete, and if there is any chance of the tumor present in an unfavorable place, your child may need further treatments like chemo and radiation therapies.

Read Also: Lymphoma in Children by Dr. Stalin Ramprakash