Sarcoma

What is Sarcoma?

Sarcoma is a type of malignant tumor that originates from connective tissue cells. Unlike most cancers that arise from epithelial cells (known as carcinomas), sarcomas primarily affect the musculoskeletal system and soft tissues. These tumors can occur in almost any part of the body but are most commonly found in the limbs, trunk, retroperitoneal area, as well as the head and neck. Sarcomas are characterized by rapid growth, early metastasis, and high aggressiveness, which necessitates prompt treatment. Early detection and appropriate therapy play a critical role in determining the prognosis.

Classification

Sarcomas comprise a diverse group of malignant tumors that vary in histological structure, localization, and clinical behavior. Several classification systems are used in medical practice, but the primary division is based on the type of tissue from which the tumor originates.

Типы сарком

By origin, sarcomas fall into two main categories:

• Soft tissue sarcomas – tumors arising from fat, muscle, fibrous, vascular, and other soft tissues;

• Bone sarcomas – malignant tumors of bone tissue.

Sarcomas are also classified by grade (low, intermediate, and high), morphological subtype (more than 70 identified types), and clinical characteristics. This diversity necessitates an individualized approach to diagnosis and treatment for each patient.

Soft Tissue Sarcomas

This group includes the following subtypes:

• Liposarcoma – originates from fat tissue;

• Leiomyosarcoma – from smooth muscle;

• Rhabdomyosarcoma – from striated muscle;

• Angiosarcoma – from blood vessels;

• Fibrosarcoma – from connective tissue;

• Synovial sarcoma – often develops near joints.

Soft tissue sarcomas can occur almost anywhere in the body and are more common in adults.

Bone Sarcomas

Among the most common malignant bone tumors are:

• Osteosarcoma – the most frequent type, especially in adolescents;

• Ewing sarcoma – an aggressive tumor typically affecting children and teenagers;

• Chondrosarcoma – arises from cartilage tissue, more often diagnosed in middle-aged and older adults.

Each type has specific features in terms of growth, metastasis, and response to treatment, which are critical for planning therapy.

Epidemiology and Statistics

Sarcoma is considered a rare type of cancer. According to international and domestic statistics, it accounts for less than 1% of all malignant tumors in adults, but about 15% in children and adolescents, making it a significant issue in pediatric oncology.

In Russia, approximately 2,000 to 2,500 new cases of various types of sarcoma are diagnosed annually. The incidence is about 2–5 cases per 100,000 people per year. Soft tissue sarcomas are more common than bone sarcomas, especially in adults. The tumor is most frequently diagnosed in individuals aged 10 to 40 but can develop at any age. Osteosarcoma and Ewing sarcoma are more prevalent in children and teens, while liposarcoma, angiosarcoma, and leiomyosarcoma are more common in adults.

Men and women are affected at similar rates, though some subtypes (such as rhabdomyosarcoma) are more frequently diagnosed in males. Thanks to advances in diagnostics and treatment, including in Russia, the overall survival rate for patients with sarcoma is gradually improving, particularly with early detection and comprehensive care.

Causes and Risk Factors

Despite progress in oncology, the exact causes of sarcoma remain largely unknown. In most cases, tumors develop spontaneously, without identifiable risk factors. However, researchers have identified several conditions that may increase the risk.

Predisposing Factors:

• Hereditary genetic syndromes. Certain rare inherited disorders significantly raise the risk of sarcoma (e.g., Li-Fraumeni syndrome (TP53 mutation), Rothmund-Thomson syndrome, neurofibromatosis type 1, familial retinoblastoma).

• Ionizing radiation. Exposure to radiation (including during treatment for other cancers) can lead to radiation-induced sarcomas years later.

• Chemical carcinogens. Contact with harmful substances (herbicides, dioxins, arsenic, asbestos) can provoke tissue changes and tumor growth.

• Immunosuppression. People with weakened immune systems (e.g., post-transplant patients or those with HIV) are at higher risk of developing various sarcomas.

• Injuries and chronic inflammation. While trauma is not considered a direct cause, long-term inflammation or old injuries may contribute to malignant transformation of cells.

• Age and gender. Some sarcomas are more common in children and teens, while others primarily affect adults.

Tumor development typically results from a complex interaction of internal (genetic) and external factors. It’s important to remember that the presence of risk factors does not guarantee the development of sarcoma, but it calls for increased vigilance and regular medical follow-up.

Symptoms

The clinical presentation of sarcoma varies depending on tumor location, size, type, and stage. In early stages, the disease is often asymptomatic, complicating timely diagnosis. As the tumor grows, certain signs may appear and should not be ignored.

Common Symptoms:

Regardless of location, sarcoma may present with the following nonspecific symptoms:

• A firm, painless mass or swelling in soft tissues;

• Gradual increase in tumor size;

• Pain in the affected area (more common in bone sarcomas);

• Limited mobility of a limb or joint;

• Fatigue, weakness, weight loss;

• Fever (less common).

A distinctive feature of sarcoma is that pain typically occurs at a late stage, when the tumor is large or compressing surrounding structures.

Symptoms by Type:

Different types of sarcoma may have their own characteristic clinical manifestations:

• Soft tissue sarcomas: often develop silently and remain unnoticed for a long time. As they grow, they may become visible or palpable. In advanced cases, skin ulceration and pain may occur.

• Bone sarcomas: such as osteosarcoma or Ewing sarcoma, often cause intense pain, especially at night or with physical activity. Swelling, gait disturbances, and pathological fractures may also occur.

• Sarcomas of internal organs: such as retroperitoneal or intestinal sarcomas, may lead to bowel obstruction, constipation, abdominal pain, bleeding, and other symptoms depending on the organ involved.

The earlier the pathology is detected, the more effective the treatment. Any suspicious mass or unexplained pain should prompt a medical evaluation.

Diagnosis of Sarcoma

Accurate and timely diagnosis is essential for selecting optimal treatment and improving outcomes. Due to the rarity and diversity of connective tissue tumors, diagnosis requires a multidisciplinary approach involving oncologists, surgeons, pathologists, and radiologists.

Main Diagnostic Steps:

1. Initial examination and history taking. The doctor assesses symptoms, duration, tumor location, trauma history, and potential risk factors. On palpation, firm, immobile masses may be detected.

2. Imaging methods: used to assess tumor size, structure, and spread:

   • MRI – preferred for soft tissue sarcomas;

   • CT scan – informative for bone tumors and metastasis detection;

   • PET-CT – used for staging and monitoring treatment response;

   • X-ray – used early on if bone sarcoma is suspected.

3. Tumor biopsy: a key diagnostic step that determines the tumor's type and grade. It may be performed as a fine-needle aspiration, core needle biopsy, or open biopsy during surgery.

4. Histological and molecular analysis: tissue samples are examined under a microscope, often using immunohistochemistry and, if necessary, molecular diagnostics (e.g., detection of specific genetic mutations).

5. Additional tests: 

   • General and biochemical blood tests;

   • Tumor markers (not always specific);

   • Ultrasound of the abdomen and chest to check for metastases.

Modern Russian healthcare facilities are equipped to perform all diagnostic steps, including high-precision morphological and genetic analysis of tumor tissue.

Treatment Methods

Treatment is based on a multidisciplinary approach, including surgery, chemotherapy, and radiation therapy. The specific strategy depends on the sarcoma type, stage, location, patient age, and overall health. The primary goal is to completely remove the tumor, prevent recurrence and metastasis, and preserve as much function as possible.

The Marus digital platform partners with leading Russian oncology centers to provide access to innovative diagnostic and treatment methods, including targeted therapy and international clinical trials. This ensures that patients receive world-class care.

Surgery

Surgical treatment is the mainstay for most localized sarcomas, especially in early stages. The goal is radical tumor removal with a margin of healthy tissue to reduce recurrence risk.

• For soft tissue sarcomas, wide excision is performed, sometimes followed by reconstruction;

• For bone sarcomas, limb-sparing surgery is often possible, though amputation may be necessary in advanced cases;

• For tumors involving internal organs, affected structures (e.g., part of the intestine or kidney) may need to be removed.

Modern techniques allow combining surgical treatment with reconstructive and plastic surgery to improve both functional and aesthetic outcomes.

Chemotherapy

Chemotherapy is used as an adjunct to surgery (neoadjuvant or adjuvant) or as primary treatment for metastatic sarcomas. It can shrink tumors before surgery or destroy residual cancer cells afterward. In some cases, chemotherapy is part of clinical trials aimed at increasing efficacy and reducing side effects.

Radiation Therapy

Radiation therapy is used:

• Before or after surgery (to shrink the tumor or prevent recurrence);

• As a primary treatment for patients who cannot undergo surgery;

• For inoperable and metastatic sarcomas.

It is particularly effective for soft tissue sarcomas, especially when combined with other treatments. Techniques include traditional external beam radiation as well as advanced methods such as IMRT (intensity-modulated radiation therapy) and proton therapy.

Prognosis and Survival

Prognosis depends on many factors: tumor type, grade, stage at diagnosis, treatment efficacy, and individual patient characteristics. The best outcomes are seen with early detection and complete surgical removal. However, the presence of metastases (especially in the lungs or bones) significantly worsens prognosis.

Thanks to improvements in oncology care in Russia, including the introduction of targeted therapy and international treatment protocols, sarcoma survival rates continue to improve. Leading Russian clinics offer personalized treatment plans, giving hope even in complex cases.

It is important to understand that long-term medical follow-up is essential even after treatment, as sarcoma may recur months or years later.