Rhabdomyosarcoma refers to one of the varieties of sarcoma - cancer of soft tissues, bones or connective tissue. The tumor most often appears in the muscles that attach to the bones. Rhabdomyosarcomas are malignant neoplasms originating in the skeletal muscle. They begin in any one part of the body or in several places at once.
Microscopically, rhabdomyosarcoma in adults has the appearance of elongated or rounded cells of a bizarre shape. More this tumor is characteristic of childhood.
Types of rhabdomyosarcoma
Rhabdomyosarcomas according to their internal structure are divided into types:
1. Embryonic rhabdomyosarcoma consists of round and spindle-shaped cells, the study of the cytoplasm of which shows a transverse or longitudinal striation. This type of rhabdomyosarcoma is most common. Embryonic rhabdomyosarcoma appears in children and adolescents. It is located in the neck or head, on the genitals, in the nasopharynx. The tumor is sensitive to radiation therapy, but prone to rapid relapse.
2. Alveolar rhabdomyosarcoma incorporates a group of cells of a round and oval shape, which are surrounded by partitions of connective tissue. This type of tumor is characterized by the appearance on the legs or arms, stomach, chest, anal area or genitals. Often it can be found in adolescents and adults on the limbs. The forecast is unfavorable.
3. The composition of pleomorphic rhabdomyosarcoma - polymorphic spindle-shaped, ribbon-like, stellate cells, tumors from which can appear on the legs or arms of people. As a rule, rhabdomyosarcoma growth occurs quickly and does not cause pain and impaired function. There is only an expansion of the veins. They often grow through the skin and become covered with ulcers, forming exophytic, bleeding tumors.
Risk factors
No environmental factors were found that increase the likelihood of this tumor. This distinguishes rhabdomyosarcoma from most cancers.
Due to the fact that the causes of the development of the tumor are not exactly known, no advice can be given to avoid its formation. However, it should be borne in mind that with adequate treatment of rhabdomyosarcoma, patients sometimes manage to fully recover.
Risk factors for the appearance of embryonic rhabdomyosarcoma are genetically caused diseases:
1. Li-Fraumeni syndrome, which is a rare disease in which a sign is inherited when enough damage to the gene from one parent, so that tumors of various types occur with high frequency. By inheritance in this pathology, the specificity of tissue reactions to a tumor is transmitted, when the likelihood of developing malignant tumors at a young age (up to 30 years) increases sharply.
2. Neurofibromatosis of the first type is the most common hereditary disease, causing a predisposition to the appearance of malignant neoplasms.
3. Beckwith-Wiedemann syndrome is a pathology characterized by macrosomia, macroglossia, and omphalocele. It also manifests itself in children with defects of the anterior abdominal wall , hernias, neonatal hypoglycemia, and divergence of the rectus muscles.
4. Costello's syndrome is a rare disease characterized by congenital anomalies: stunting, gross facial features, skin changes.
5. Noonan syndrome is a genetic disease characterized by stunting and abnormalities in somatic development. It can develop in the whole family or in its individual members.
Infants who were large and tall at birth have a greater risk of embryonic rhabdomyosarcoma than others. As a rule, the causes of embryonic rhabdomyosarcoma are unknown. A sign of the disease is the appearance of a tumor, becoming more and more.
Symptoms
The symptomatology of the disease is determined by the form of cancer. An urgent medical consultation is required if the listed signs of oncology are observed in children:
- swelling or swelling, increasing in size or not passing, sometimes painful;
- bulging eyes;
- Strong headache;
- difficulties with bowel movements and urination;
- the appearance of blood in the urine;
- hemorrhage in the rectum, throat, nose.
Diagnostics
To date, no methods have been developed for determining rhabdomyosarcoma until the appearance of its first obvious symptoms.
The earliest signs of oncology are local swelling or tightening, which does not cause problems or pain at first. This symptom is characteristic of rhabdomyosarcoma of the arms, legs, and trunk.
If the tumor is located in the peritoneum or pelvic area, abdominal pain, vomiting, or constipation may occur. This is embryonic rhabdomyosarcoma of the retroperitoneal space. Less commonly, developing in the biliary tract, rhabdomyosarcoma causes jaundice.
If there is a suspicion of this neoplasm, it is necessary to conduct a biopsy, which will clarify what kind of rhabdomyosarcoma has arisen.
In most cases, rhabdomyosarcoma occurs in areas where it is easily detected, for example, in the nasal cavity or outside the eyeball. If the eye bulges out, or nasal discharge appears, you should immediately consult a doctor with a suspected tumor in order to diagnose it at an early stage of its development. In the case when rhabdomyosarcoma appears on the surface of the body, it is easily detected without a deep examination. This is the so-called embryonic soft tissue rhabdomyosarcoma.
In 30% of patients, embryonic rhabdomyosarcoma is found at an early stage when it can be completely removed. But in the vast majority of patients, a detailed examination reveals small metastases, the treatment of which requires chemotherapy.
Embryonic rhabdomyosarcomas located in the testis area are most often formed in young children and are detected by the child's parents when washing. If tumors occur in the urinary tract, they cause difficulty urinating or spotting - symptoms that cannot be ignored.
Tumor stages
1. The first stage. The tumor can be of any size, but it has not yet spread to the nodes of the lymphatic system and is located in one of the prognostically favorable areas of the body:
- eyes or periocular region;
- neck and head (excluding tissue in the area of the brain and spinal cord);
- biliary tract and gall bladder;
- in the uterus or testicles.
Places that are not listed are considered unfavorable areas.
2. The second stage. The tumor is located in one of the unfavorable zones (zones that are not on the list of favorable ones). The tumor size does not exceed 5 cm, and there was no spread to the lymph nodes.
3. The third stage. The tumor is located in an unfavorable area, and one of the conditions is met:
- the size of the tumor is less than 5 cm, and it spread to the nearest lymph nodes;
- the size of the tumor exceeds 5 cm, and there is a risk that it will spread to the nearest lymph nodes.
4. The fourth stage. The size of the tumor can be any, and it spread to the nearest lymph nodes. Cancer has spread to distant areas of the body.
Risk groups
The risk group assigned to the patient determines the likelihood of rhabdomyosarcoma recurrence. Any child receiving treatment for embryonic rhabdomyosarcoma must necessarily receive additional chemotherapy to reduce the likelihood of tumor recurrence. The type of antitumor drug, the dosage and the number of sessions - all this is determined by the risk group the child belongs to - low, intermediate or high.
Treatment options
Patients with embryonic rhabdomyosarcoma can be treated in different ways.
Treatment of malignant tumors implies separate methods that are considered traditional. Other techniques are in clinical trials. Clinical trials have been resorted to to improve existing treatment methods or to increase the amount of data on the latest treatments for patients with rhabdomyosarcoma. If, as a result of clinical trials, it turns out that the new treatment methods are superior to traditional, then the new treatment method goes into the category of traditional.
Since malignant neoplasms tend to appear in different areas of the body, a large number of types of treatment are used. The treatment of rhabdomyosarcoma in children is supervised by a pediatric oncologist.
Among the treatment methods there are those that can cause side effects, even when a lot of time has passed since the treatment.
Surgery
The surgical method, or tumor removal, is widely used in the treatment of rhabdomyosarcoma. This operation is called "wide local excision." This intervention involves the removal of a tumor and part of adjacent tissues along with the lymph nodes, which also affects rhabdomyosarcoma. Treatment sometimes consists of several operations. The following factors influence the decision about the purpose of an operation and its type:
- place of initial tumor localization;
- what functions of the child’s body are affected by the tumor;
- the reaction of the tumor to radiation therapy or chemotherapy, which can be used as a matter of priority.
In most children, removal of the entire tumor volume by surgery is not possible.
Soft tissue embryonic rhabdomyosarcoma tends to form in various places of the body, each of which requires its own operation. Surgical intervention is indicated in the case of rhabdomyosarcoma of the genitals or eyes, if a biopsy confirms the diagnosis. Before surgery, chemotherapy or radiation therapy can be prescribed to reduce large tumors, which cannot be operated on to simplify the task of removing cancer.
Even if the doctor manages to remove the entire tumor, patients should be subjected to chemotherapy at the end of the operation to suppress the surviving cancer cells. Along with chemotherapy, radiation therapy is also used. Treatment aimed at reducing the risk of relapse is called adjuvant therapy.
Radiation therapy
With this type of treatment, x-ray or other types of radiation are used. Radiation therapy is aimed at killing tumor cells or stopping its growth. Two methods of radiation therapy have found their application in medicine - external and internal.
The external uses a radiation source outside the human body to irradiate the tumor area. Internal radiation therapy, or brachytherapy, irradiates a tumor with the placement of radioactive substances in the immediate vicinity of it inside the human body. It is used to treat cancer of the bladder, head, neck, prostate, vulva.
The type of radiation therapy and dose are determined by the age of the child and the type of tumor, its initial localization, as well as the presence of tumor residues and the degree of tumor coverage of the nearest lymph nodes after surgery.
Chemotherapy
This is a type of tumor treatment that uses medical agents to stop the growth of cancer cells. Chemotherapy helps kill these cells or avoid dividing them. When conducting a course of systemic chemotherapy, drugs are taken orally or administered intravenously or intramuscularly. Entering the bloodstream, drugs act on tumor cells throughout the body. With regional chemotherapy, drugs are injected directly into the organs and cavities of the body, as well as into the cerebrospinal fluid. Combination chemotherapy is often used, which is a treatment in which more than one anticancer drug is used. The method of chemotherapy is selected depending on the type and stage of development of the neoplasm.
Chemotherapy is indicated for every child who is being treated for rhabdomyosarcoma. It allows you to minimize the likelihood of relapse. The choice of medicine, its dose and the number of procedures are determined by the risk group of rhabdomyosarcoma.
New treatments
New treatments for rhabdomyosarcoma undergoing tests:
- Large doses of chemotherapy in combination with stem cell transplantation. The method allows you to organize the replacement of hematopoietic cells that are destroyed during cancer treatment. Immature blood cells before treatment are removed from the bone marrow or blood of the patient and preserved. At the end of chemotherapy, conserved stem cells are re-preserved and returned to the patient by infusion. Thus, blood cells are restored.
- Immunotherapy. With this type of treatment, the patient’s immune system is used to fight cancer. The drugs used are used to increase or restore the body's natural defense against cancer. This type of tumor treatment is called biotherapy.
- Targeted therapy. This type of therapy is directed against metastases. Targeted therapy is based on the use of special antibodies that bind to a cancer cell. These antibodies are similar to traditional antibodies of the human body. However, they are high-tech drugs. Thanks to targeted therapy in the treatment of "chemistry" you can find and attack only cancer cells without harming healthy cells. In rhabdomyosarcoma, angiogenesis inhibitors are used as targeted therapy. These drugs interfere with the formation of blood vessels in neoplasms. This leads to the fact that the tumor is starving and stops growing. Angiogenesis inhibitors and monoclonal antibodies are types of agents undergoing clinical trials to combat embryonic rhabdomyosarcoma.