Overview
Soft tissue sarcomas are malignant tumors originating in the body’s soft tissues, including muscles, fat, joints, nerves, and blood vessels. Although they represent about 1% of all cancers, with approximately 30 new cases per million people annually, their rarity doesn’t diminish their seriousness. Various types exist, each classified by the tissue they develop from:
- Liposarcoma: Arises in fat tissue.
- Fibrosarcoma: Develops in fibrous tissues.
- Leiomyosarcoma: Originates in smooth muscle, found in blood vessels and intestines.
- Rhabdomyosarcoma: Starts in skeletal muscle, typically in the trunk and limbs.
- Angiosarcoma: Emerges from blood vessels.
Cause
Studies have connected soft tissue sarcomas to exposure to certain chemicals and high-dose radiation, to certain viral infections, and to specific genetic abnormalities. In most cases, however, the cause is not known.
Symptoms of Soft Tissue Sarcoma
For many individuals, the first noticeable symptom of soft tissue sarcoma is a painless, slow-growing lump in the trunk or limbs. As the tumor increases in size, it may start pressing on nearby nerves or muscles, potentially causing pain, numbness, or skin breakdown.
Doctor Examination
Soft-tissue lumps or masses are more commonly benign (noncancerous) than malignant (cancerous). During an examination, your doctor will evaluate the mass using imaging studies and other diagnostic tools. If soft tissue sarcoma is suspected, you will be referred to an oncologist (cancer specialist) for further evaluation.
Diagnosing and Staging Soft Tissue Sarcoma
Imaging studies and diagnostic tests are essential in determining the tumor’s size, location, and potential spread to other parts of the body. These evaluations also provide critical information about the disease’s prognosis. Tumors larger than 5 cm and located deep within the tissues are more likely to be cancerous.
- Magnetic Resonance Imaging (MRI): MRIs are particularly useful for identifying the size, depth, and exact location of a tumor. They provide a detailed view of the tumor’s relationship with muscles, fat, nerves, and blood vessels. MRIs are also used to monitor the tumor’s response to treatment and track disease progression.
- X-rays: X-rays help evaluate whether a tumor has affected nearby bones or contains calcifications. Tumors such as synovial sarcoma and liposarcoma may show calcium deposits that can aid in diagnosis.
- Computerized Tomography (CT) Scans: CT scans outline bone involvement and are particularly useful in detecting cancer spread to the lungs, abdomen, or pelvis. CT scans may also be preferred over MRIs for patients with metal implants near the affected area.
- Biopsy: A biopsy is often required to confirm a diagnosis of soft tissue sarcoma. During this
- Other Tests: Bone scans can detect whether the tumor has spread to nearby or distant bones. Positron Emission Tomography (PET) scans are helpful in monitoring a tumor’s response to treatment and identifying hidden tumors in other parts of the body.
Grading of Tumors
Grading helps assess the aggressiveness of the cancer cells in a soft tissue tumor. Using a tissue sample obtained during the biopsy, a pathologist determines the type of cancer, its origin, and whether it is of high or low grade. Grading plays a vital role in staging the disease and planning treatment. Doctors are meticulous during biopsy procedures to prevent contamination of healthy tissue with cancer cells.
Treatment of Soft Tissue Sarcomas
Soft tissue sarcomas require a multidisciplinary approach involving a team of specialists, including a surgeon, radiation oncologist, medical oncologist, and pathologist. The primary treatment goal is t
Surgery
The scope of surgery depends on factors such as the size and location of the tumor, the extent of tissue removal needed, and the expected functional outcome.
- Excision: When the sarcoma has not metastasized, the tumor and a margin of surrounding tissue are surgically removed to minimize the risk of recurrence. This may involve removing healthy tissue adjacent to the tumor. Advances in reconstructive surgery allow for the transfer and repair of skin, blood vessels, and nerves, enabling larger tissue removal while preserving limb functionality.
- Amputation: In cases where removing the tumor would require sacrificing essential nerves, blood vessels, or muscle, amputation may be necessary. While limb preservation is preferred, amputation followed by a well-fitted prosthetic can provide better functionality and quality of life if the preserved limb would otherwise be numb or nonfunctional.
Radiation Therapy
Radiation therapy is commonly used alongside surgery to reduce the likelihood of the tumor returning at the same site. It may be administered before or after surgery, depending on the tumor’s location and the doctor’s evaluation.
Chemotherapy
The use of chemotherapy in treating soft tissue sarcomas remains debated. While its benefits in improving survival are modest, certain drugs, such as doxorubicin (Adriamycin®) and ifosfamide (Ifex®), have shown effectiveness.
Emerging targeted therapies, like imatinib (Gleevec®), focus on specific cellular traits and have demonstrated success in treating specific sarcomas, such as gastrointestinal stromal tumors (GIST). Chemotherapy is often reserved for high-risk cases, such as large, aggressive tumors with a high potential for spreading, particularly in younger patients.
Recovery and Follow-Up
Recovery varies depending on the tumor type and individual response to treatment. Regular follow-up visits with your doctor are essential to monitor for recurrence. Tumors that return may develop at the original site or metastasize to distant locations, such as the lungs. Early detection is critical, as recurrent tumors can pose significant challenges. In some cases, a second surgery to remove recurring or metastatic tumors may improve outcomes and extend the patient’s lifespan.
Types of Soft Tissue Sarcoma
The World Health Organization classifies soft tissue sarcomas into 19 categories with over 50 distinct histological types. Below are some of the most recognized types:
Liposarcoma
Liposarcoma is composed of fatty tissue and typically appears as a painless, enlarging mass deep within the muscles of the limbs, abdomen, or buttocks. These tumors may go unnoticed for extended periods, potentially progressing into more aggressive forms. Surgical removal is the primary treatment. Commonly seen in adults over 50, the disease’s progression depends on the tumor’s type and location.
Subtypes include:
- Well-differentiated liposarcoma: Typically occurs in the limbs, rarely spreads, and is non-lethal.
- Dedifferentiated liposarcoma: More aggressive and often found in the abdomen or groin, with a higher risk of recurrence and metastasis.
- Myxoid liposarcoma: Rare, occurs in younger individuals, often found in the thigh muscles.
- Round cell liposarcoma: Frequently coexists with the myxoid type and is prone to recurrence and metastasis.
Fibrosarcoma
This malignant tumor originate
- Adult fibrosarcoma: Typically affects middl
- Infantile fibrosarcoma: Congenital and usually appears before age two. It has a better prognosis, wit
Myxofibrosarcoma
The most common malignant soft tissue tumor in older adults, it frequently affects the lower limbs, particularly the thigh. Often painless, it can grow undetected in the ab
Rhabdomyosarcoma
Rhabdomyosarcoma is the most prevalent malignant soft tis
Synovial Sarcoma
Often located deep in the muscles of the limbs, synovial sarcoma is more common in young males in their 30s. It may remain small for years before enlarging. These tumors have a genetic abnormality and a high risk of spreading to the lungs, sometimes over 5 to 10 years, necessitating long-term follow-up.
Epithelioid Sarcoma
A rare tumor affecting the forearm, hand, trunk
Alveolar Soft Part Sarcoma
This slow-growing tumor occurs mostly in adolescents and young adults, often in the thigh or head and neck regions. It ca
Clear Cell Sarcoma
Affects young adults aged 20 to 40, this tumor grows beneath the skin, often in the tendons or muscle sheaths of the foot and ankle. It is associated with genetic abnormalities and has a high recurrence and metastasis risk, even after 10 years.
Leiomyosarcoma
Common in middle-aged and older adults, leiomyosarcoma arises from blood vessels in the trunk and limbs. Abdominal tumors are more challenging to treat and may obstruct vital organs. Limb-based tumors are easier to manage but may still spread to the lungs or liver.
Gastrointestinal Stromal Tumor (GIST)
A rare abdominal tumor, GIST often grows unnoticed until it becomes large. While surgical removal is challenging, targeted drug therapies like imatinib (Gleevec®) have significantly improved treatment outcomes.
Outcomes
Survival rates for soft tissue sarcoma vary based on factors like age, tumor size, grade, and spread. Five-year survival rates range around 65%, with the best outcomes for small, low-grade tumors that have not metastasized.
Effective treatment often includes complete surgical removal, supplemented by radiation therapy when needed. Recurrence rates are 5% to 20% at the original site and 30% to 50% in other organs. Surgical removal of metastases (metastatectomy) can extend survival for appropriate patients.
Future Directions
Advances in treatment rely on better chemotherapy protocols, targeted therapies, and improved diagnostic and surgical techniques. Early detection and personalized therapies will be critical in improving survival and quality of life for patients with soft tissue sarcomas.