What is soft tissue sarcoma?

Cancers originating from connective tissues are referred to as sarcomas. Soft tissue sarcoma is a very rare type of tumor with over fifty subtypes. Normally, one encounters one malignant bone tumor per one million people. In contrast, sarcomas, which are malignant tumors of soft tissues, are observed four to five times more frequently compared to malignant bone tumors. They make up 4% of adult tumors and 7-10% in children.

Soft tissue tumors can be either benign or malignant. According to research conducted by the Rizzoli Orthopedic Institute, 43.6% of all soft tissue tumors are malignant, while 56.4% are benign tumors.

How many types of soft tissue sarcoma are there?

There are over fifty subtypes of soft tissue sarcomas. Those originating from muscle are called rhabdomyosarcoma, from connective tissue fibrosarcoma, from fat tissue liposarcoma, and from nerve tissue neurosarcoma.

The frequency of occurrence of these sarcomas is linked to age groups. For instance, rhabdomyosarcomas and synovial sarcomas are common in the pediatric and adolescent age groups, while other sarcomas are encountered in adults.

What are the causes of soft tissue sarcoma?

The exact cause of soft tissue sarcomas is not fully understood. In some cases, a genetic predisposition can be observed when looking at certain groups of patients. Soft tissue sarcomas are associated with some genetic conditions, such as neurofibromatosis, where benign neurofibromas can develop on nerve tissue, and sometimes neurofibrosarcomas can occur.

Lipomatosis is another condition with a familial predisposition. In this condition, lipomas form in the body, and these lipomas can potentially develop into liposarcomas.

In each type of soft tissue sarcoma, a DNA mutation is typically observed, known as an oncogene. These mutations can contribute to the development of a sarcoma.

Who gets soft tissue sarcoma?

Soft tissue sarcoma can occur in both men and women at nearly the same rates. Soft tissue sarcomas can develop at almost any age, affecting children, adolescents, and adults equally.

What are the risk factors of soft tissue sarcoma?

While certain risk factors are associated with some cancer types, there is no known specific risk factor for soft tissue sarcomas. Smoking and chemicals have also been implicated in soft tissue cancers. Additionally, the role of diet and trauma is emphasized. For example, some patients may recall experiencing trauma in the area where soft tissue sarcoma later develops. It is believed that physical traumas such as severe blows or accidents can contribute to the development of soft tissue cancer.

Soft tissue sarcomas can occur not only in the extremities but also in the internal organs of the abdomen because connective tissues exist there as well. Chemicals like vinyl chloride, agricultural pesticides, and arsenic are known to cause sarcomas in the liver.

Radiation exposure is also said to play a role in the development of soft tissue sarcoma. For instance, a patient with a bone tumor who receives radiation therapy in that area may develop a malignant soft tissue tumor in the same region 5-10 years later.

What are the symptoms of soft tissue sarcoma?

The symptoms of soft tissue sarcoma manifest as swelling, pain, and functional impairment depending on where the sarcoma has developed, its size, and its proximity to blood vessels or nerves.

The anatomical location where soft tissue sarcoma develops is crucial and can affect its early or late detection. For instance, when soft tissue sarcoma develops in a region like the arm or leg, there may be a visible swelling that makes it easier to detect.

On the other hand, a soft tissue sarcoma that develops behind the knee may not be visible, but it can lead to restricted movement. Patients may find it difficult to bend their knee and move comfortably in such cases. In the case of a sarcoma developing around the hip, limping may be observed while walking.

In summary, the symptoms can be summarized as follows:

1. Swelling

2. Pain

3. Loss of function in the area where the tumor has developed

How is soft tissue sarcoma diagnosed?

Similar to some other cancers, soft tissue sarcoma does not have a very specific laboratory test. For instance, in prostate cancer, PSA levels serve as a test that can trigger suspicion, but in the case of soft tissue sarcoma, there is no available blood test that clearly indicates the disease.

Patient history, physical examination, and imaging techniques become crucial in the diagnosis of soft tissue sarcoma. Among imaging tests, X-rays do not provide significant contributions in the case of this disease. While an ultrasound may not lead to a definite diagnosis, it can raise suspicion about the disease. The most effective imaging methods include MRI (Magnetic Resonance Imaging), computed tomography (CT) angiography, MR angiography, and PET-CT. However, the definitive diagnosis is made through a biopsy. A fine needle biopsy is used to obtain a sample from the site of the tumor without causing trauma, and this sample determines whether the soft tissue sarcoma is benign or malignant. In cases where soft tissue sarcoma develops in proximity to internal organs, the diagnosis is made through an interventional radiology-guided biopsy conducted under the guidance of a CT scan.

How is soft tissue sarcoma treated?

In orthopedic oncology, a multidisciplinary approach is always employed for diagnosis and treatment. Throughout the diagnostic process, as well as in planning and monitoring treatment and post-treatment care, collaboration with other medical departments is essential. Radiology, interventional radiology, radiation oncology, medical oncology, and at times, psychiatry departments work together.

The primary treatment for soft tissue sarcoma is surgery. In some cases, depending on the localization, size, and pathological structure of the tumor, neoadjuvant therapy, meaning chemotherapy and/or radiation therapy before surgery, may be applied. After this treatment, surgical intervention is planned.

Following surgery, some patients may also receive chemotherapy and radiation therapy. If a wide surgical margin cannot be achieved or if there is suspicion of tumor presence at the surgical margin, localized radiation therapy is used. In definitive surgical treatment, the aim is to remove the tumor tissue while leaving a 1 or 2 cm healthy tissue margin around it.

The malignancy grade of the tumor, whether it is low or high grade, determines the form of treatment. Additionally, factors such as local tumor presence, regional, or distant spread are crucial criteria both in treatment planning and predicting the lifespan.

In surgery, limb-sparing surgery is preferred. Amputations are not performed as they were in the past. However, in very rare cases where certain blood vessels and nerves cannot be saved or repaired, amputation may be necessary.

FREQUENTLY ASKED QUESTIONS ABOUT SOFT TISSUE SARCOMA