There are more than 50 different types of soft tissue sarcomas (Figure 1). The number of new cases is 3.4 per 100,000 people per year and the number of deaths is 1.3 per 100,000 people per year. The relative survival after 5 years for all soft tissue sarcomas is 65%.
Soft tissue sarcomas are rare cancers, which represent between 1 to 2% of all cancers. These are malignant tumors developed within connective tissue or supporting cells.
They are named after the type of normal tissue cells that cancer cells look like when observed under a microscope. More than 50% of soft tissue sarcomas originate in limbs. They develop more often in lower limbs than in upper limbs, especially in the thigh.
Biopsy is essential before any treatment to ensure proper patient management according to the type of tumor. Several histological, immunohistochemical and molecular analyzes are then carried out in accordance with the two major complementary classifications in force, Sarcoma of Soft Tissues coming from the World Health Organization (WHO) and the National Federation of Centers for the Fight Against Cancer (FNCLCC).
The origin of soft tissue sarcomas is still relatively unknown, the majority of them are said to be idiopathic that is to say that no cause can be found. However, we know that it exists some predisposing factors responsible for the occurrence of these tumors, such as rare genetic diseases (retinoblastoma, Werner syndrome), exposure to ionizing radiation or viruses such as herpes or HIV.