Soft-Tissue Sarcoma

What soft-tissue sarcoma is — in plain words

Most cancers begin in the lining of an organ — the bowel, the breast, the lung. Sarcomas are different. They start in the body's connective tissue: the muscle that moves your limbs, the fat that pads them, the blood vessels and nerves that supply them, the tendons that anchor them. Anywhere there is connective tissue, a sarcoma can — very rarely — arise.

"Soft-tissue sarcoma" is therefore an umbrella term, not a single disease. There are roughly fifty distinct subtypes under that umbrella, each with its own behaviour and its own preferred treatment. That sounds overwhelming. In practice, only a handful of subtypes account for most cases, and the early steps in the workup are the same for almost all of them.

Sarcomas are uncommon — about one in every hundred adult cancers. Because they are rare, they are best looked after by teams that see them often. The single biggest predictor of a good outcome is being managed at, or in close consultation with, a centre that treats sarcoma every week.

Where soft-tissue sarcomas tend to appear

Signs and symptoms to take seriously

The classic story for a limb sarcoma is a lump that is painless, deeper than a normal "skin" lump, larger than a golf ball, and slowly getting bigger. Any one of those features deserves a scan. All of them together is a sarcoma until proven otherwise.

• A lump larger than 5 cm — about the size of a small lemon — at any site.
• A deep lump that you cannot easily move under the skin, or that feels fixed to the muscle beneath it.
• A lump that is growing over weeks to months, even slowly.
• A new lump after a previous one was removed from the same area — a possible recurrence.
• Unexplained abdominal swelling, a feeling of fullness, or a vague mass on the abdomen — possible retroperitoneal sarcoma.

Most lumps turn out to be benign — a lipoma, a cyst, a haematoma. But the cost of a quick MRI to settle the question is small; the cost of missing a sarcoma is large. We would always rather see ten benign lumps than miss one sarcoma.

"The single most important sentence in sarcoma care is this — the biopsy should be planned by the team that will do the surgery. Get that right, and the rest of treatment becomes simpler. Get it wrong, and we are often picking up the pieces for months."

How soft-tissue sarcoma is diagnosed

The workup is a defined sequence. Skipping a step, or doing one in the wrong order, can change the treatment plan and the outcome. The right order is:

• MRI of the primary site — for limb and trunk tumours, MRI is the single best scan. It shows the size of the tumour, which structures it touches, and whether the surgeon can take it out with a clean margin. For retroperitoneal tumours, a high-quality CT of the abdomen is usually the first scan.
• CT scan of the chest — the lungs are by far the most common site for sarcoma to spread to. A CT chest is part of staging for almost every sarcoma, regardless of where it started.
• Core-needle biopsy, planned by the operating team — a small tissue sample taken under image guidance through a carefully chosen path. The needle track must lie within the area the surgeon plans to remove. This is the single most consequential decision in the workup.
• Specialist pathology review — sarcoma pathology is a sub-specialty in itself. The biopsy slides should be reviewed by a pathologist who reports sarcomas regularly. Molecular and immunohistochemical tests pin down the exact subtype.
• Further imaging where appropriate — a PET-CT for high-grade tumours, an MRI of the brain only for the rare subtypes that travel there, and an echocardiogram before chemotherapy if doxorubicin is planned.

The main subtypes — a short tour

Each of the subtypes below behaves differently and has its own dedicated page on this site. The list is not exhaustive — there are dozens more — but these are the ones we see most often.

Grade and stage — what they mean

Two numbers do most of the work in describing a sarcoma:

• Grade — how aggressive the cells look under the microscope. Low-grade tumours grow slowly and rarely spread. High-grade tumours grow faster and are more likely to send out metastases. Grade is the single most important predictor of behaviour.
• Stage — a summary that combines the size of the tumour, its depth, whether it has reached lymph nodes (uncommon in sarcoma), and whether it has spread to distant sites (usually the lungs).

Most localised sarcomas — those still confined to the place they started — are stage I to III. Stage IV means the cancer has spread to a distant site, most commonly the lungs.

How we treat soft-tissue sarcoma

Treatment is always a team decision. A sarcoma surgeon, a medical oncologist, a radiation oncologist, a sarcoma pathologist and a musculoskeletal radiologist meet to review every case. The exact plan depends on the subtype, the grade, the size, and the location — but the building blocks are the same.

Surgery — the backbone

For nearly every localised soft-tissue sarcoma, surgery is the main treatment. The aim is a wide excision with negative margins — removing the tumour together with a cuff of normal tissue around it, so no cancer cells are left behind. In the limbs, modern surgery is almost always limb-sparing; amputation is now a rare exception. In the retroperitoneum, surgery may need to take a kidney, a piece of bowel, or part of a major blood vessel with the tumour.

Radiation therapy

Radiation is often added to surgery for high-grade tumours, large tumours, or tumours where a clean margin will be tight. It can be given before surgery (to shrink the tumour and reduce the field treated) or after surgery (with a larger dose to a larger area). The choice between the two depends on the tumour and the team's experience.

Chemotherapy

For high-grade, large, or chemosensitive sarcomas, chemotherapy is added — sometimes before surgery, sometimes after, sometimes both. The classic combination is doxorubicin with ifosfamide. Not every sarcoma needs chemotherapy; for low-grade and small tumours, surgery alone is often enough. Read more about chemotherapy →

Targeted therapy and immunotherapy

A handful of sarcoma subtypes respond to targeted drugs — imatinib for GIST, pazopanib for several other subtypes, larotrectinib for the rare NTRK-fusion tumours. For advanced synovial sarcoma, a new engineered T-cell therapy (afami-cel) is changing the landscape. We test for the relevant markers on every patient. Read more about immunotherapy →

What the outlook honestly looks like

The outlook for soft-tissue sarcoma depends much more on the subtype, the grade, the size, and the completeness of surgery than on any single number. As a rough guide:

• For small, low-grade, completely removed sarcomas, the chance of cure is well over 90%.
• For large, high-grade localised sarcomas, the chance of long-term cure is typically in the 50–70% range with combined treatment.
• For sarcomas that have spread to the lungs, cure is sometimes still possible if a small number of lung nodules can be removed surgically; in other cases, the aim of treatment shifts to controlling the disease for as long as possible with good quality of life.

These are averages. Your own situation will look different in important ways, and we will always be honest with you about what the realistic range is for your particular tumour.

Life during treatment

For a limb sarcoma, surgery is usually the most disruptive part of treatment — a period of recovery, often physiotherapy, sometimes a temporary brace or crutches. Most people regain very good function within a few months. Radiation adds skin reactions and fatigue but is generally well tolerated. Chemotherapy is the hardest stretch — usually four to six cycles over a few months, with hair loss, fatigue, and a higher risk of infection during the low-count days.

Through all of it, ordinary life carries on. Many patients keep working, especially between chemotherapy cycles. Family, prayer, friends, simple meals, gentle movement — these are not optional extras; they are part of how people get through treatment well.

After treatment — long-term follow-up

Because sarcomas can return locally or in the lungs years after the original treatment, follow-up is long. Typical schedule:

• Clinic review with examination of the surgical site every 3–4 months for the first 2–3 years.
• MRI of the primary site at intervals decided by the team — more often for high-grade tumours.
• CT chest every 6 months for the first 2 years, then yearly to year 5, then less often.
• After 5 years, visits and scans become less frequent — but they do not stop entirely for at least 10 years.

Read about survivorship care →

The single most important message

If you remember nothing else, remember this: a possible sarcoma needs an MRI and a referral, not a quick excision in a non-specialist clinic. A properly planned biopsy by the team that will operate is the foundation of everything that follows. It is worth waiting a week, or travelling, to get this step right.