When to seek medical advice

Talk to your doctor if you develop a lump that persists or if you have signs or symptoms that may indicate either bone or soft tissue sarcoma. Many soft tissue and bone tumors are benign. However, the only way to determine whether a sarcoma is benign or malignant is for a doctor to examine a sample of the tissue.

Screening and diagnosis

If your doctor suspects you have sarcoma, he or she will take a medical history and perform a physical exam. Imaging tests, such as X-rays, computerized tomography (CT) scans, ultrasound and magnetic resonance imaging (MRI), enable your doctor to see and evaluate the area of concern. Your doctor also may request a bone scan, a procedure in which you're injected with a tiny amount of radioactive material, called a tracer, which can be detected by a special camera used to create images of your bones.

Determining whether a tumor is malignant requires removal of a sample of tissue (biopsy) from the tumor for examination, generally under a microscope. If your doctor suspects you have either a bone or soft tissue sarcoma, ask for a referral to a cancer doctor (oncologist) who specializes in sarcomas.

Techniques for removing a sample of a suspected sarcoma include:

• Needle biopsy. Your doctor uses a thin needle to remove small pieces of tissue from the tumor. There are two types of needle biopsy — fine-needle aspiration and core biopsy. A core biopsy involves using a slightly larger needle to remove a small, solid core of tissue.

• Surgical biopsy. Your doctor makes an incision through your skin and removes either an entire tumor (excisional biopsy) or a portion of a tumor (incisional biopsy). In some cases you may need only local anesthesia. For a larger or deep-seated tumor, you'll likely require general anesthesia for the procedure. It's important that a doctor experienced in the treatment of sarcomas perform the excisional biopsy.

Grading and staging

Besides determining whether the tissue is cancerous, examining tissue can determine how aggressive the cancer is (its grade). Further testing, such as scans and blood tests, will determine if the cancer has spread and how far (its stage).

Soft tissue sarcomas, like many cancers, are staged according to a system developed by the American Joint Committee on Cancer. With soft tissue cancers, the oncologist looks at tumor size and location, its spread to lymph nodes, its spread to distant organs and its grade — how much the tumor looks like normal tissue, which indicates how quickly it's growing — to determine whether the cancer is stage IA through IVB. The five-year survival rate for stage I soft tissue sarcomas is 99 percent. It drops to 50 percent for stage III.

There's no similar staging system for osteosarcoma. Rather, there are only two stages, depending on whether the cancer is contained in one part of the body (localized) or has spread to other parts (metastasized).

Complications

The complications of bone sarcomas may include weakened bones and bone fractures. If the cancer spreads to other organs, complications include dysfunction of the affected organ, such as shortness of breath if it spreads to your lungs. With soft tissue sarcomas, because soft tissue is fairly elastic, tumors can grow large, pressing on normal tissue, causing soreness or pain.