Soft Tissue Sarcoma

Soft Tissue Sarcoma (STS)

What is Soft Tissue Sarcoma?

Soft tissue sarcoma (STS) is a type of cancer that begins in the soft tissues like fat, muscles, nerves, blood vessels, tendons, and connective tissues. It can occur anywhere in the body.

• 60% – Found in arms or legs.

• 30% – Found in the torso or abdomen.

• 10% – Found in the head and neck.

• Though it affects people of all ages, it is more common in children.

Common Sites of STS

• Blood vessels

• Fat cells

• Joint linings

• Muscles

• Nerves

• Tendons

There are over 70 different types of STS, each named after the type of cell or tissue from which it originates.

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Statistics

• In 2023, 13,400 new STS cases are expected to be diagnosed in the United States.

• The 5-year survival rate for STS in the United States is approximately 65%.

Risk Factors for STS

Although the exact cause of many sarcomas remains unknown, several risk factors increase the chances of developing STS:

1. Previous Radiation Therapy:

• People who underwent radiation therapy over five years ago are at higher risk of developing sarcoma at the treatment site.

2. Genetic Disorders:

• Conditions like neurofibromatosis type 1, Li-Fraumeni syndrome, retinoblastoma, Werner syndrome, and familial adenomatous polyposis increase the risk of sarcoma.

3. Weakened Immune System:

• Individuals with HIV/AIDS, leukemia, lupus, or other autoimmune disorders.

4. Lymphedema:

• Swelling in limbs or other areas following surgery or radiation therapy may lead to angiosarcoma.

5. Exposure to Chemicals:

• Long-term exposure to certain industrial chemicals increases the risk.

Symptoms of STS

Symptoms depend on the location of the sarcoma:

• Painless lump or swelling in the arm or leg.

• Pain may develop as the tumor grows and presses on nerves or muscles.

• Lumps larger than 2 inches (5 cm) or those that cause pain should be evaluated by a doctor.

• Abdominal sarcomas may cause bleeding or abdominal swelling.

• Uterine sarcomas may lead to abnormal bleeding or enlargement of the uterus.

Diagnosis of STS

• X-ray

• Ultrasound

• CT Scan

• MRI

• PET-CT

• Biopsy: A small tissue sample is taken and analyzed under a microscope to confirm cancer.

• Types of biopsy: Needle biopsy, incisional biopsy, excisional biopsy.

Treatment Options for STS

1. Surgery

• Surgery removes the tumor along with a margin of healthy tissue.

• For low-grade tumors, surgery alone may be sufficient.

• For high-grade tumors larger than 2 inches, a combination of surgery and radiation therapy or chemotherapy is often used.

• In some cases, amputation may be required to remove large tumors involving critical nerves and blood vessels.

2. Radiation Therapy

• High-energy radiation destroys cancer cells.

• Radiation can shrink tumors before surgery (neoadjuvant) or eliminate remaining cancer cells after surgery (adjuvant).

• External Beam Radiation Therapy (EBRT) is the most common type.

• IMRT and SBRT techniques focus radiation precisely, minimizing damage to surrounding tissues.

• Side effects include fatigue, skin redness, itching, and swelling.

3. Chemotherapy

• Chemotherapy uses drugs to kill cancer cells. It is usually given in cycles.

• Common drugs for STS include:

• Doxorubicin

• Ifosfamide

• Gemcitabine

• Docetaxel

• Paclitaxel

• Side effects may include fatigue, nausea, vomiting, hair loss, infections, and diarrhea.

4. Targeted Therapy

• Targets specific genes and proteins involved in the growth of cancer.

• Common targeted therapy drugs:

• Imatinib (Gleevec)

• Pazopanib (Votrient)

• Tazemetostat (Tazverik)

• Pexidartinib (Turalio)

5. Immunotherapy

• Boosts the body’s immune system to fight cancer cells.

• Immunotherapy drugs for STS:

• Atezolizumab (Tecentriq)

• Tumor-agnostic treatments.

Follow-Up Care

• Regular follow-ups are essential to monitor for recurrence and manage side effects.

• Follow-ups may include:

• Physical exams

• Blood tests

• Imaging tests like X-rays, CT scans, or MRIs.

STS can be challenging to treat, but early detection and timely intervention significantly improve outcomes. Continuous follow-ups ensure that patients remain healthy and catch any recurrence at the earliest stage.

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