Soft tissue sarcoma is a rare and infrequent tumor that encompasses more than 60 subtypes and is responsible for up to 2% of all cancer deaths. Know its symptoms and treatment to address it in time.
Soft tissue sarcoma (STS) is a rare variety of cancer that comprises a group of more than 60 subtypes. It affects the delicate parts of the body, such as muscles, nerves, tendons, body fat, or blood or lymphatic vessels.
Although they are tumors that can appear anywhere in the body, most of them develop in the extremities since most of the muscles, blood vessels, and nerves are located along the arms and legs. Its origin can be superficial (the skin, the walls of the trunk, or the abdomen) or deeper (the viscera or the body’s organs).
Noticing a painless lump under the skin or significant inflammation in any of these soft tissues of our body (usually located in the arms or legs) can be a warning sign of the appearance of this type of sarcoma. We are going to the doctor immediately, who, when suspecting the disease, will order imaging tests and biopsy, which can help to diagnose it early. In other cases, when the sarcoma has grown and presses on organs, nerves, or muscles, there may be pain or trouble breathing normally.
STS constitute 1% of all malignant tumors and are responsible for 2% of mortality due to cancer. They can be diagnosed at all ages, even in children and adolescents, although it is more common in adults between 40 and 60.
Incidence and Prevalence of Soft Tissue Sarcoma
In Europe, there are only 27,908 new cases of sarcomas per year, of which 84% correspond to soft tissue sarcomas and 14% to bone sarcomas. The incidence of soft tissue sarcoma in Europe stands at 1 in 20,000 people a year. This figure decreases when focusing only on Spain, being 3.1 cases per year per 100,000 inhabitants.
The life expectancy of patients with soft tissue sarcoma varies depending on the stage at which the disease is diagnosed. In the European Union, 5-year overall survival ranges from 15% for patients with metastases to 90% for those with the localized disease without metastasis. However, between 40% and 50% of patients will develop metastases during the infection, so life expectancy tends to be low in a large percentage of diagnosed cases.
Causes and types of soft tissue sarcoma
Soft tissue sarcoma (STS) is challenging to diagnose and often has an unknown origin. However, it is known that certain risk factors can lead to the onset of the disease.
First, up to 5% of soft tissue sarcomas can be caused by radiation therapy to treat other breast cancer or lymphoma tumors. In these cases, it would be secondary cancer that usually develops in the radiation area. These sarcomas are typically diagnosed around ten years after radiation treatment.
Genetics can also influence the development of these tumors. Thus, it is known that some hereditary genetic diseases such as neurofibromatosis, Gardner syndrome, or Li-Fraumeni syndrome have been related to the presence of some types of tumors.
Finally, Kaposi’s sarcomas are usually related to immunosuppression processes or viral infections such as those caused by HIV or the human herpesvirus 8 (HHV-8).
Types of soft tissue sarcomas
STBs are classified based on the tissue in which they originate. Although there are more than 60 different tumors, they share many of their characteristics, which allows them to be grouped for study and treatment purposes. Only certain subtypes have distinctive specific features and require special treatment, such as gastrointestinal stromal tumors (GISTs).
These tumors (GIST) originate in specific cells of the digestive tract known as interstitial cells of Cajal, and their incidence increases after 60 years of age. The stomach is where these tumors most commonly develop, followed by the small intestine, rectum, colon, and esophagus.
Of the more than 60 different types of soft tissue sarcomas, the most common are :
- Liposarcomas: originate in the body’s adipose (fat) tissue and account for 25% of sarcomas in adults. They are usually detected between the ages of 50 and 65. Its most frequent location is in the lower extremities, but it can also appear behind the peritoneum, in the arms, neck, or chest.
- Leiomyosarcomas: originate in smooth muscles located in internal organs such as the intestines, stomach, uterus, or blood vessels. They are involuntary muscles, that is, those that perform automatic functions without our controlling their movements. Its incidence increases with age.
- Rhabdomyosarcomas: originate in the muscles used to move the skeleton and are therefore especially common in the arms and legs. Its incidence is higher in children than in adults.
- Angiosarcomas: can originate in the blood vessels (hemangiosarcomas) or the lymphatic vessels (lymphangiosarcomas). Kaposi’s sarcoma is a type of vascular sarcoma that develops more frequently in the elderly and immunosuppressed people due to medical treatment – as is the case in transplant patients – or due to infections such as HIV.