ConditionCancer
Sarcoma
Sarcoma is a group of rare cancers that start in the body's connective tissues: fat, muscle, blood vessels, nerves, cartilage and bone. There are more than 70 types, divided into soft tissue sarcomas and bone sarcomas. The most common sign is a painless, growing lump, often deep in the thigh, arm or trunk. Bone sarcomas cause bone pain, often worse at night, and swelling, mainly in teenagers and young adults. Treatment at a specialist sarcoma center, usually with surgery and often radiotherapy or chemotherapy, gives the best outcomes.
Also called: Soft tissue sarcoma, bone sarcoma, connective tissue cancer
At a glance
- What it is
- Cancer arising from connective tissues such as fat, muscle, nerves, blood vessels, cartilage or bone.
- How common
- Rare: about 1% of adult cancers but a larger share of childhood cancers.
- Warning signs
- A lump that is growing, larger than 5 cm, deep or painful. Persistent bone pain, especially at night.
- Diagnosis
- Ultrasound, MRI or CT, then a core needle biopsy at a sarcoma center.
- Treatment
- Surgery with clear margins, often radiotherapy, chemotherapy for some types, targeted and immunotherapy for selected sarcomas.
When to get help
See a doctor within a day or two
- A lump that is growing, larger than 5 cm (2 inches), deep under the muscle, or painful
- Bone pain that is persistent, worsening, or wakes you at night, especially in a teenager or young adult
- A broken bone after very minor injury, with prior pain at that site
- A lump that has come back after being removed
Book a routine appointment
- Any new lump present for more than 3 to 4 weeks
- A swelling in the abdomen with feeling full quickly, or unexplained weight loss
- Family history of Li-Fraumeni syndrome or neurofibromatosis with a new lump
Usually safe to manage at home
- Small, soft, unchanging lumps under the skin that a doctor has already assessed as benign
Types of sarcoma
Soft tissue sarcomas
About 80% of sarcomas. Common types:
| Type | Tissue | Typical patients and sites |
|---|---|---|
| Undifferentiated pleomorphic sarcoma | Unclear | Older adults, limbs |
| Liposarcoma | Fat | Adults, thigh and abdomen (retroperitoneum) |
| Leiomyosarcoma | Smooth muscle | Adults, uterus, abdomen, blood vessels |
| Synovial sarcoma | Unclear origin | Young adults, near joints |
| Malignant peripheral nerve sheath tumor | Nerve | People with neurofibromatosis type 1 |
| Rhabdomyosarcoma | Skeletal muscle | Children, head and neck, genitourinary area |
| Angiosarcoma | Blood vessels | Skin of scalp, breast after radiotherapy |
| Kaposi sarcoma | Blood vessels | People with HIV or immune suppression |
| Gastrointestinal stromal tumor (GIST) | Gut wall | Adults, stomach and small bowel |
See soft tissue sarcoma for more detail.
Bone sarcomas
- Osteosarcoma: the most common primary bone cancer, peaking in teenagers, often around the knee or upper arm
- Ewing sarcoma: children and young adults, pelvis, legs, ribs
- Chondrosarcoma: cartilage cancer in adults, pelvis and shoulder
Risk factors
Most sarcomas have no known cause. Risk factors include:
- genetic syndromes: Li-Fraumeni syndrome, neurofibromatosis type 1, hereditary retinoblastoma
- previous radiotherapy to the area, years earlier
- chronic lymphedema (angiosarcoma)
- chemical exposures such as vinyl chloride
- Paget's disease of bone (bone sarcomas in older adults)
- HHV-8 infection with immune suppression (Kaposi sarcoma)
Symptoms
Soft tissue sarcoma
- a painless lump that gradually grows over weeks or months
- pain if the lump presses on nerves or muscles
- abdominal sarcomas may cause swelling, fullness, pain or bowel symptoms
- uterine sarcomas can cause abnormal vaginal bleeding
Bone sarcoma
- bone pain, often worse at night or with activity, not settling
- swelling or a lump over the bone
- limping or reduced movement
- fracture after a minor injury
Pain in growing teenagers is often blamed on sports or growing pains, which can delay diagnosis.
Diagnosis
Specialist guidelines advise imaging any lump that is larger than 5 cm, growing, deep or painful.
- ultrasound: first test for most lumps
- MRI: shows the extent of limb and trunk tumors
- X-ray: first test for bone pain
- CT of the chest and abdomen to check for spread, PET-CT in some cases
- core needle biopsy: done at or planned with a sarcoma center, so the biopsy track can be removed during later surgery
- pathology and molecular tests: identify the exact subtype, often using genetic changes characteristic of specific sarcomas
Removing a suspicious lump without proper imaging and planning ("whoops" excision) can make later surgery more extensive.
Treatment
Treatment is planned by a multidisciplinary sarcoma team.
Surgery
The main treatment for most localized sarcomas: removing the tumor with a margin of healthy tissue. Limb-sparing surgery is possible in the large majority of limb sarcomas. Reconstruction may involve grafts, flaps or bone replacements.
Radiotherapy
Often given before or after surgery for soft tissue sarcomas to reduce local recurrence. Proton therapy is used in some children and in sites near critical structures.
Chemotherapy
- standard part of treatment for osteosarcoma, Ewing sarcoma and rhabdomyosarcoma
- used in selected adult soft tissue sarcomas and for advanced disease
Targeted therapy and immunotherapy
- imatinib and other kinase inhibitors for GIST
- other targeted drugs for specific subtypes
- immunotherapy for some sarcoma types
Outlook
Outlook depends on type, grade, size, location, whether it has spread and how completely it is removed. Small, low-grade sarcomas removed with clear margins have excellent outcomes. Overall 5-year survival for localized soft tissue sarcoma is high, and lower for sarcomas that have spread. Follow-up scans continue for at least 5 to 10 years.
Frequently asked questions
What is a sarcoma?
A sarcoma is a cancer that starts in connective tissue such as fat, muscle, blood vessels, nerves, cartilage or bone. There are more than 70 types, grouped into soft tissue sarcomas and bone sarcomas.
What does a sarcoma lump feel like?
A soft tissue sarcoma is often a painless, firm lump that grows over weeks to months and may be deep and fixed. Lumps larger than 5 cm, growing, deep or painful should be scanned. Most lumps are not sarcoma, but checking is important.
How is sarcoma diagnosed?
Diagnosis uses imaging, usually ultrasound or MRI for soft tissue lumps and X-ray for bone pain, followed by a core needle biopsy, ideally at a specialist sarcoma center. CT scans check for spread.
What causes sarcoma?
Most sarcomas have no known cause. Risk is higher with inherited syndromes such as Li-Fraumeni and neurofibromatosis, previous radiotherapy, chronic lymphedema and some chemical exposures.
Is sarcoma curable?
Many sarcomas are curable, especially when found early and removed completely by experienced surgeons. Treatment at a specialist center improves outcomes. Advanced sarcomas are harder to cure but can often be controlled.
Sources
This guide was written from current patient and clinical guidance, including:
- American Cancer Society: Soft tissue sarcoma; Bone cancer
- National Cancer Institute: Soft tissue sarcoma treatment (PDQ); Osteosarcoma and Ewing sarcoma
- National Comprehensive Cancer Network (NCCN): Soft tissue sarcoma and bone cancer guidelines
- NICE: Suspected cancer: recognition and referral (NG12)
- Sarcoma Foundation of America: About sarcoma