Soft tissue sarcomas

What is a soft tissue sarcoma?

Soft tissue sarcomas are rare malignant tumors. Less than one percent of newly diagnosed cancers in Switzerland each year are sarcomas.

Malignant tumors that develop in surface tissues such as your skin, mucous membrane or glandular tissue are called carcinomas. When malignant tumors form in connective, fatty, cartilage, muscle and bone tissue or in the blood vessels, medicine calls them sarcomas (Greek sarcos = flesh and oma = tumor).

Tumors in the soft tissues are often benign tumors; malignant tumors, known as soft tissue sarcomas, are rare. The various tumors are named after their place of origin. A benign soft tissue tumor in your fatty tissue, for example, is called a lipoma, while a malignant liposarcoma is called a liposarcoma. A benign tumor in your connective tissue is fibroma, a malignant tumor is fibrosarcoma. In adulthood, they most frequently grow in the connective and fatty tissue or in the smooth muscles. The most common soft tissue cancer in children is rhabdomyosarcoma, which forms in muscle fibers.

Soft tissue sarcomas most frequently occur on the arms or legs. Less frequently, they form in the abdomen, chest or head and neck area.

Soft tissue sarcoma: causes and risk factors

Why sarcomas form in the soft tissue has not yet been sufficiently researched. However, there are known factors that increase your risk of illness:

Carcinogenic substances: Frequent contact with toxic chemicals increases the risk of cancer. These include:

• Arsenic
• Pesticides (pesticides)
• Weed killers (herbicides)
• Fungicides (fungicides)
• Asbestos
• Dioxin
• Polyvinyl chloride (PVC)

Radiotherapy: If you received radiotherapy in childhood for another cancer, your risk of developing soft tissue sarcoma at the site is increased.

Gene mutations: Certain genetic mutations are possible triggers for malignant soft tissue tumors, as well as genetic diseases such as Gardner’s syndrome, Recklinghausen’s disease or Li-Fraumeni syndrome.

Viral infections: Some infections with viruses (e.g. HIV) or disorders (e.g. diseases of the immune system) promote soft tissue cancer.

Chronic inflammation or irritation in the tissue increases the risk of tumors.

You can develop soft tissue sarcoma at any age. However, the majority of those affected are over 50 years old. Men fall ill more often than women.

Symptoms: Rapidly growing swelling of the tissue

A soft tissue sarcoma initially causes hardly any symptoms. You will usually notice a painless swelling at first and believe that it is a harmless bruise. However, the swelling grows quickly within weeks and months. If the lump forms under the skin, you can feel it. If it becomes larger, it can cause a feeling of tension or pain. In addition to pain, movement restrictions also occur in some cases.

If the sarcoma grows inside the body, it is usually only discovered when it causes pain, for example because it presses on nerves or periosteum or grows into surrounding organs.

If the soft tissue sarcoma grows in the gastrointestinal tract (gastrointestinal stromal tumors = GIST), it can cause a feeling of fullness in the stomach or pain in the stomach or intestines. If the tumor grows larger, those affected suffer from a feeling of fullness, nausea, stomach and intestinal bleeding.

General symptoms can also develop as the disease progresses:

• You lose weight unintentionally.
• You feel tired and exhausted.
• You have a slight fever (up to around 38 degrees).
• Their performance decreases.
• They are exceptionally pale.

Soft tissue sarcomas can spread. Daughter tumors often develop in the lungs, less frequently in the bones, lymph nodes or other organs such as the liver.

Soft tissue sarcoma: Diagnosis with us

If we suspect that you are suffering from a soft tissue tumor, we will first take a medical history and ask you in detail about your symptoms.

Indications of a malignant soft tissue tumor include

• The tumor has grown within a few weeks or months.
• It cannot be moved under the skin.
• You will feel pain at this point.
• You break out in a sweat at night.
• You have lost weight unintentionally.

If it turns out that you are suffering from a swelling that occurred without a previous injury and quickly increased in size, we will schedule further examinations.

Imaging procedures allow us to take a look inside your body.

X-ray

An X-ray gives us an initial orientation. In the picture you can see the first so-called soft tissue shadows. The procedure is also suitable for localizing metastases in the lungs, for example.

Magnetic resonance imaging (MRI)

MRI is considered the most reliable imaging examination for soft tissue sarcomas of the arms and legs. Based on the images, we can determine the position and size of the sarcoma. The procedure also makes it possible to observe the course of the disease and healing process during and after treatment.

Computer tomography (CT)

The CT images show the organs in the abdomen or chest, the brain or the lymph nodes in cross-section. Using CT, we can determine the location and extent of soft tissue sarcomas in the abdomen, chest, arms or legs.

Ultrasound (sonography)

Sonography shows changes in the tissue. In contrast to most benign soft tissue tumors, malignant soft tissue tumors are very well supplied with blood, which we can detect using modern ultrasound equipment.

Positron emission tomography (PET/CT or PET/MR)

Positron emission tomography (tracer: FDG) can be used to visualize metastases in lymph nodes and organs in addition to the primary tumor.

Biopsy

To determine the type and aggressiveness of the soft tissue tumor, we usually also take a tissue sample. It is important in order to be able to plan the subsequent therapy.

Soft tissue sarcoma: prevention, early detection, prognosis

There are no effective measures to prevent soft tissue sarcoma. Take care to avoid carcinogenic substances such as asbestos or dioxin.

Early detection is also hardly possible. You can only make sure that you have existing tumors checked regularly and inform us of any changes in size.

Course and prognosis

The course and prognosis of a soft tissue sarcoma depend on how large the tumor was at the start of treatment and where it is located. Another decisive factor is whether the sarcoma has already formed metastases and where they are located. If we succeed in removing the tumor completely, the course and prognosis are usually good.

However, since soft tissue tumors can form again (recurrences), regular follow-up checks are important. If you suffer from a benign form of soft tissue tumor, the disease usually progresses well and does not limit your life expectancy.

Self-help groups

Soft tissue sarcoma: treatment with chemotherapy, radiotherapy and surgery

If you suffer from a malignant soft tissue tumor, your treatment should be carried out in specialized centers. The choice of treatment method depends on the type of sarcoma and how advanced your disease is.

The treatment is based on the three pillars of cancer therapy:

• Surgery
• Chemotherapy
• Radiotherapy

Surgery is the most important method of treating a soft tissue sarcoma. Chemotherapy or radiotherapy can accompany the operation. If the three treatment options are combined, this can be done simultaneously or one after the other.