Soft-tissue sarcoma | |
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Undifferentiated soft tissue sarcoma in left lung of young child | |
Specialty | Oncology |
A soft-tissue sarcoma (STS) is a malignant tumor, a type of cancer, that develops in soft tissue. [1] A soft-tissue sarcoma is often a painless mass that grows slowly over months or years. They may be superficial or deep-seated. Any such unexplained mass must be diagnosed by biopsy. [2] Treatment may include surgery, radiotherapy, chemotherapy, and targeted drug therapy. [3] Bone sarcomas are the other class of sarcomas.
There are many different types, many of which are rarely found. [4] The World Health Organization lists more than fifty subtypes. [2]
Tissue of origin | Type of cancer | Usual location in the body |
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Fibrous tissue | Undifferentiated pleomorphic sarcoma (UPS) | Legs |
Dermatofibrosarcoma protuberans | Trunk | |
Synovial sarcoma | Legs | |
Fat | Liposarcoma | Arms, legs, trunk |
Muscle (striated) | Rhabdomyosarcoma | Arms, legs |
Muscle (smooth) | Leiomyosarcoma | Uterus, digestive tract |
Blood vessels | Angiosarcoma | Arms, legs, trunk, radiated tissues |
Kaposi sarcoma | Legs, trunk | |
Lymph vessels | Angiosarcoma | Arms |
Peripheral nerves | Malignant peripheral nerve sheath tumor / Neurofibrosarcoma | Arms, legs, trunk |
Cartilage and bone-forming tissue | Extraskeletal myxoid chondrosarcoma | Legs |
Extraskeletal osteosarcoma | Legs, trunk (not involving the bone) |
Tissue of origin | Type of cancer | Most common locations in the body | Most common ages |
---|---|---|---|
Muscle (striated) | Embryonal and Alveolar rhabdomyosarcoma | Head and neck, genitourinary tract | Infant–6 |
Alveolar soft part sarcoma | Arms, legs, head, and neck | 10–19 | |
Muscle (smooth) | Leiomyosarcoma | Trunk | 15-35+ |
Fibrous tissue | Undifferentiated pleomorphic sarcoma | Legs | 15–19+ |
Dermatofibrosarcoma protuberans | Trunk | 15–19 | |
Synovial sarcoma | Legs, arms, and trunk | 15–35 | |
Fat | Liposarcoma | Arms and Legs | 15–19+ |
Peripheral nerves | Malignant peripheral nerve sheath tumors (also called neurofibrosarcomas) | Arms, legs, and trunk | 15–19+ |
Cartilage and bone-forming tissue | Extraskeletal myxoid chondrosarcoma | Legs | 15-35 |
An earlier version of this article was taken from the US National Cancer Center's Cancer Information Service. The names of several sarcomas have changed over time.
In their early stages, soft-tissue sarcomas usually do not cause symptoms. Because soft tissue is relatively elastic, tumors can grow rather large, pushing aside normal tissue, before they are felt or cause any problems. The first noticeable symptom is usually a painless lump or swelling. As the tumor grows, it may cause other symptoms, such as pain or soreness, as it presses against nearby nerves and muscles. If in the abdomen it can cause abdominal pains commonly mistaken for menstrual cramps, indigestion, or cause constipation. [5]
Most soft-tissue sarcomas are not associated with any known risk factors or identifiable cause. There are some exceptions:
The only reliable way to determine whether a soft-tissue tumor is benign or malignant is through a biopsy. The two methods for acquisition of tumor tissue for cytopathological analysis are:
A pathologist examines the tissue under a microscope. The pathologist may be the most important person in the treatment of sacomas, because they are responsible for making the proper diagnosis. Pathologists at expert sarcoma centers are invaluable in identifying the type of sarcoma responsible for a patient's symptoms. If cancer is present, the pathologist can usually determine the type of cancer and its grade. Here, grade refers to a scale used to represent concisely the predicted growth rate of the tumor and its tendency to spread, and this is determined by the degree to which the cancer cells appear abnormal when examined under a microscope. Low-grade sarcomas, although cancerous, are defined as those that are less likely to metastasise. High-grade sarcomas are defined as those more likely to spread to other parts of the body. For soft-tissue sarcoma, the two histological grading systems are the National Cancer Institute system and the French Federation of Cancer Centers Sarcoma Group system. [9] [10] [11]
Soft-tissue sarcomas commonly originate in the upper body, in the shoulder or upper chest. Some symptoms are uneven posture, pain in the trapezius muscle, and cervical inflexibility [difficulty in turning the head]. [12] The most common site to which soft-tissue sarcoma spreads is the lungs. [13]
In general, treatment for soft-tissue sarcomas depends on the stage of the cancer. The stage of the sarcoma is based on the size and grade of the tumor, and whether the cancer has spread to the lymph nodes or other parts of the body (metastasized). Treatment options for soft-tissue sarcomas include surgery, radiotherapy, chemotherapy, and targeted drug therapy. [3]
Soft-tissue sarcoma research requires significant effort due to its rarity; successful research requires substantial collaboration. Year by year, the medical field is learning that the various types cannot be lumped together and each sarcoma needs to be considered a different type of cancer. [18]
As a novel form of treatment used in other cancers, immunotherapy may have an role in treating soft-tissue sarcomas like alveolar soft part sarcoma and pleomorphic undifferentiated sarcoma. However, as of 2023, only alveolar soft part sarcoma has a regulatory approval for such an agent, in this case atezolizumab. [19]
When the immunological constant of rejection signature (ICR) was retrospectively applied ICR to 1455 non-metastatic STS and searched for correlations between ICR classes and clinicopathological and biological variables; thirty-four per cent of tumors were classified as ICR1, 27% ICR2, 24% ICR3, and 15% ICR4. These classes were associated with patients’ age, pathological type, and tumor depth, and an enrichment from ICR1 to ICR4 of quantitative/qualitative scores of immune response. ICR1 class was associated with a 59% increased risk of metastatic relapse when compared with ICR2-4 class. In multivariate analysis, ICR classification remained associated with metastasis-free survival, as well as pathological type and Complexity Index in Sarcomas (CINSARC) classification, suggesting independent prognostic value. [20]
ICR signature is independently associated with postoperative MFS in early-stage STS, independently from other prognostic features, including CINSARC. A robust prognostic clinicogenomic model integrating ICR, CINSARC, and pathological type, and suggested differential vulnerability of each prognostic group to different systemic therapies. [20]
Soft-tissue sarcomas are very uncommon cancers. They account for less than 1% of all new cancer cases each year. [21]
In 2023, about 14,300 new cases were diagnosed in the United States. [21] Soft-tissue sarcomas are more commonly found in older patients (>50 years old), although in children and adolescents under age 20, certain histologies are common (rhabdomyosarcoma, synovial sarcoma). [13]
Around 3,300 people were diagnosed with soft-tissue sarcoma in the UK in 2011. [22]
A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant (cancerous) tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondary tumors, which most commonly have spread from tumors located outside the brain, known as brain metastasis tumors. All types of brain tumors may produce symptoms that vary depending on the size of the tumor and the part of the brain that is involved. Where symptoms exist, they may include headaches, seizures, problems with vision, vomiting and mental changes. Other symptoms may include difficulty walking, speaking, with sensations, or unconsciousness.
A sarcoma is a malignant tumor, a type of cancer that arises from cells of mesenchymal origin. Connective tissue is a broad term that includes bone, cartilage, muscle, fat, vascular, or other structural tissues, and sarcomas can arise in any of these types of tissues. As a result, there are many subtypes of sarcoma, which are classified based on the specific tissue and type of cell from which the tumor originates.
Uterine cancer, also known as womb cancer, includes two types of cancer that develop from the tissues of the uterus. Endometrial cancer forms from the lining of the uterus, and uterine sarcoma forms from the muscles or support tissue of the uterus. Endometrial cancer accounts for approximately 90% of all uterine cancers in the United States. Symptoms of endometrial cancer include changes in vaginal bleeding or pain in the pelvis. Symptoms of uterine sarcoma include unusual vaginal bleeding or a mass in the vagina.
Endometrial cancer is a cancer that arises from the endometrium. It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most often vaginal bleeding not associated with a menstrual period. Other symptoms include pain with urination, pain during sexual intercourse, or pelvic pain. Endometrial cancer occurs most commonly after menopause.
Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different cell types including epithelial cells, germ cells, and stromal cells. When these cells become abnormal, they have the ability to divide and form tumors. These cells can also invade or spread to other parts of the body. When this process begins, there may be no or only vague symptoms. Symptoms become more noticeable as the cancer progresses. These symptoms may include bloating, vaginal bleeding, pelvic pain, abdominal swelling, constipation, and loss of appetite, among others. Common areas to which the cancer may spread include the lining of the abdomen, lymph nodes, lungs, and liver.
Rhabdomyosarcoma (RMS) is a highly aggressive form of cancer that develops from mesenchymal cells that have failed to fully differentiate into myocytes of skeletal muscle. Cells of the tumor are identified as rhabdomyoblasts.
Angiosarcoma is a rare and aggressive cancer that starts in the endothelial cells that line the walls of blood vessels or lymphatic vessels. Since they are made from vascular lining, they can appear anywhere and at any age, but older people are more commonly affected, and the skin is the most affected area, with approximately 60% of cases being cutaneous (skin). Specifically, the scalp makes up ~50% of angiosarcoma cases, but this is still <0.1% of all head and neck tumors. Since angiosarcoma is an umbrella term for many types of tumor that vary greatly in origin and location, many symptoms may occur, from completely asymptomatic to non-specific symptoms like skin lesions, ulceration, shortness of breath and abdominal pain. Multiple-organ involvement at time of diagnosis is common and makes it difficult to ascertain origin and how to treat it.
Dermatofibrosarcoma protuberans (DFSP) is a rare locally aggressive malignant cutaneous soft-tissue sarcoma. DFSP develops in the connective tissue cells in the middle layer of the skin (dermis). Estimates of the overall occurrence of DFSP in the United States are 0.8 to 4.5 cases per million persons per year. In the United States, DFSP accounts for between 1 and 6 percent of all soft-tissue sarcomas and 18 percent of all cutaneous soft-tissue sarcomas. In the Surveillance, Epidemiology and End Results (SEER) tumor registry from 1992 through 2004, DFSP was second only to Kaposi sarcoma.
Chondrosarcoma is a bone sarcoma, a primary cancer composed of cells derived from transformed cells that produce cartilage. A chondrosarcoma is a member of a category of tumors of bone and soft tissue known as sarcomas. About 30% of bone sarcomas are chondrosarcomas. It is resistant to chemotherapy and radiotherapy. Unlike other primary bone sarcomas that mainly affect children and adolescents, a chondrosarcoma can present at any age. It more often affects the axial skeleton than the appendicular skeleton.
A synovial sarcoma is a rare form of cancer which occurs primarily in the extremities of the arms or legs, often in proximity to joint capsules and tendon sheaths. It is a type of soft-tissue sarcoma.
A leiomyosarcoma (LMS) is a rare malignant (cancerous) smooth muscle tumor. The word is from leio- 'smooth' myo- 'muscle' and sarcoma 'tumor of connective tissue'. The stomach, bladder, uterus, blood vessels, and intestines are examples of hollow organs made up of smooth muscles where LMS can be located; however, the uterus and abdomen are the most common sites.
A malignant peripheral nerve sheath tumor (MPNST) is a form of cancer of the connective tissue surrounding peripheral nerves. Given its origin and behavior it is classified as a sarcoma. About half the cases are diagnosed in people with neurofibromatosis; the lifetime risk for an MPNST in patients with neurofibromatosis type 1 is 8–13%. MPNST with rhabdomyoblastomatous component are called malignant triton tumors.
Desmoplastic small-round-cell tumor (DSRCT) is an aggressive and rare cancer that primarily occurs as masses in the abdomen. Other areas affected may include the lymph nodes, the lining of the abdomen, diaphragm, spleen, liver, chest wall, skull, spinal cord, large intestine, small intestine, bladder, brain, lungs, testicles, ovaries, and the pelvis. Reported sites of metastatic spread include the liver, lungs, lymph nodes, brain, skull, and bones. It is characterized by the EWS-WT1 fusion protein.
Undifferentiated pleomorphic sarcoma (UPS), also termed pleomorphic myofibrosarcoma, high-grade myofibroblastic sarcoma, and high-grade myofibrosarcoma, is characterized by the World Health Organization (WHO) as a rare, poorly differentiated neoplasm. WHO classified it as one of the undifferentiated/unclassified sarcomas in the category of tumors of uncertain differentiation. Sarcomas are cancers derived mesenchymal stem cells that typically develop in bone, muscle, fat, blood vessels, lymphatic vessels, tendons, and ligaments. More than 70 sarcoma subtypes have been described. The UPS subtype of these sarcomas consists of tumor cells that are poorly differentiated and may appear as spindle-shaped cells, histiocytes, and giant cells. UPS is considered a diagnosis that defies formal sub-classification after thorough histologic, immunohistochemical, and ultrastructural examinations fail to identify the type of cells involved.
Ewing sarcoma is a type of pediatric cancer that forms in bone or soft tissue. Symptoms may include swelling and pain at the site of the tumor, fever, and a bone fracture. The most common areas where it begins are the legs, pelvis, and chest wall. In about 25% of cases, the cancer has already spread to other parts of the body at the time of diagnosis. Complications may include a pleural effusion or paraplegia.
Soft tissue sarcoma refers to a broad group of tumors that originate from connective tissues. They tend to have similar histologic appearance and biological behavior, and can be either benign or malignant. Soft tissue sarcomas can arise in any part of the pet's body but skin and subcutaneous tumors are the most commonly observed. Soft-tissue sarcomas comprise approximately 15% of all skin and subcutaneous tumors in dogs and approximately 7% of all skin and subcutaneous tumors in cats. The variety of different tumors that fall under the category of soft tissue sarcomas includes fibrosarcoma, hemangiopericytoma, liposarcoma, rhabdomyosarcoma, leiomyosarcoma, malignant fibrous histiocytoma, malignant nerve sheath tumors, myxosarcoma, myxofibrosarcoma, mesenchymoma, and spindle cell tumor.
Kaposi's sarcoma (KS) is a type of cancer that can form masses on the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple and may be flat or raised. Lesions can occur singly, multiply in a limited area, or may be widespread. Depending on the sub-type of disease and level of immune suppression, KS may worsen either gradually or quickly. Except for Classical KS where there is generally no immune suppression, KS is caused by a combination of immune suppression and infection by Human herpesvirus 8.
Follicular dendritic cell sarcoma (FDCS) is an extremely rare neoplasm. While the existence of FDC tumors was predicted by Lennert in 1978, the tumor wasn't fully recognized as its own cancer until 1986 after characterization by Monda et al. It accounts for only 0.4% of soft tissue sarcomas, but has significant recurrent and metastatic potential and is considered an intermediate grade malignancy. The major hurdle in treating FDCS has been misdiagnosis. It is a newly characterized cancer, and because of its similarities in presentation and markers to lymphoma, both Hodgkin and Non-Hodgkin subtypes, diagnosis of FDCS can be difficult. With recent advancements in cancer biology better diagnostic assays and chemotherapeutic agents have been made to more accurately diagnose and treat FDCS.
The Immunologic Constant of Rejection (ICR), is a notion introduced by biologists to group a shared set of genes expressed in tissue destructive-pathogenic conditions like cancer and infection, along a diverse set of physiological circumstances of tissue damage or organ failure, including autoimmune disease or allograft rejection. The identification of shared mechanisms and phenotypes by distinct immune pathologies, marked as a hallmarks or biomarkers, aids in the identification of novel treatment options, without necessarily assessing patients phenomenologies individually.
Myxofibrosarcoma (MFS), although a rare type of tumor, is one of the most common soft tissue sarcomas, i.e. cancerous tumors, that develop in the soft tissues of elderly individuals. Initially considered to be a type of histiocytoma termed fibrous histiocytoma or myxoid variant of malignant fibrous histiocytoma, Angervall et al. termed this tumor myxofibrosarcoma in 1977. In 2020, the World Health Organization reclassified MFS as a separate and distinct tumor in the category of malignant fibroblastic and myofibroblastic tumors.