Soft Tissue Sarcoma: Staging and Treatment

What is staging for cancer?

Staging is a way to find out how much cancer is in your body, how far it has spread, and what treatment can be used. Staging looks at the size of the tumor, where it is, and if it has spread to other organs. Tests like CT, bone scan, MRI,PET scan, and biopsies may be done to help stage your cancer. Your providers need to know about your cancer and your health so that they can plan the best treatment for you.

How is soft tissue sarcoma staged?

Soft tissue sarcoma is staged depending on what area of the body the tumor is in:

• Trunk and extremities.
• Retroperitoneum.
• Abdomen and thoracic visceral organs.
• Head and neck.

(There is standard staging only for the trunk and extremities and the retroperitoneum).

STS staging is also based on:

• The size of your tumor on imaging tests and what is found after surgery.
• Any evidence of spread to other organs (metastasis).
• Surgery to test if your lymph nodes have cancer cells.
• The histologic grade, or how the cells look under a microscope.

Staging is classified using the American Joint Committee on Cancer’s “TNMG system”:

• T (tumor)- describes the size/location/extent of the "primary" tumor.
• N (nodes)- describes if the cancer has spread to the lymph nodes.
• M (metastases)- describes if the cancer has spread to other organs (called metastases).
• G (grade)- describes how the cells look under a microscope. The “G” is determined by three factors: cell differentiation, mitotic count, and tumor necrosis.

Staging for STS is hard because there are many types of STS and a few places where a tumor can form. Most STS forms in the extremities (arms and legs), often in the thigh. Most other tumors are found in the trunk of the body (abdomen, chest, pelvis and back), head and neck, or the retroperitoneum (organs in the back of the abdomen, like the kidneys and pancreas). The staging system is very complex. Talk to your provider about the stage of your cancer. Below is more information on the different stages of STS.

Soft Tissue Sarcoma of the Trunk and Extremities

Stage IA (T1, N0, M0, G1/GX): The cancer is 5cm or smaller, has not spread to nearby lymph nodes or distant sites. It is grade I or the grade can’t be determined.

Stage IB (T2/T3/T4 N0, M0, G1/GX): The tumor is 5-10cm (T2), 10-15cm (T3), or larger than 15cm (T4). No spread to lymph nodes or distant sites. It is grade I or the grade can’t be determined.

Stage II (T1, N0, M0, G2/G3): The tumor is 5cm or smaller, no spread to lymph nodes or to distant sites. It is grade II or grade III.

Stage IIIA (T2, N0, M0, G2/G3): The tumor is 5-10cm, has not spread to nearby lymph nodes or to distant sites. It is grade II or grade III.

Stage IIIB (T3/T4, N0, M0, G2/G3): The tumor is 10-15cm (T3) or larger than 15cm (T4), has not spread to lymph nodes or distant sites. It is grade II or grade III.

Stage IV (Any T, N1, M0, any G): The cancer is any size and has spread to lymph nodes. It has not spread to different sites, and it can be any grade.

Stage IV (Any T, any N, M1, any G): The cancer is any size. It has spread to nearby lymph nodes and to distant sites. It can be any grade.

Soft Tissue Sarcoma of the Retroperitoneum

Stage IA (T1, N0, M0, G1/GX): The cancer is 5cm or smaller. It has not spread to lymph nodes or to different sites. It is grade I or the grade can’t be determined.

Stage IB (T2/T3/T4, N0, M0, G1/GX): The tumor is 5-10cm (T2), 10-15cm (T3), or larger than 15cm (T4). It has not spread to lymph nodes or distant sites. The cancer is grade I or the grade can’t be assessed.

Stage II (T1, N0, M0, G2/G3): The tumor is 5cm or smaller. It has not spread to lymph nodes or to distant sites. It is grade II or III.

Stage IIIA (T2, N0, M0, G2/G3): The tumor is 5-10cm. It has not spread to lymph nodes or to distant sites. It is grade II or grade III.

Stage IIIB (T3/T4, N0, M0, G2/G3): The tumor is 10-15cm (T3), or bigger than 15cm (T4). It has not spread to lymph nodes or to distant sites. It is grade II or grade III.

Stage IIIB (Any T, N1, M0, Any G): The cancer is any size and has spread to lymph nodes. It has not spread to distant sites. It can be any grade.

Stage IV (Any T, Any N, M1, Any G): The cancer is any size and has spread to lymph nodes and to distant sites. It can be any grade.

How is Soft Tissue Sarcoma Treated?

Since STS is so rare, you should find a provider who has treated this cancer before. Treatment of STS is based on many things, like your age, overall health and history, the size and location of the tumor, the grade, and if the tumor has spread.

Your treatment may include:

• Surgery.
• Radiation Therapy.
• Chemotherapy.
• Targeted Therapy.
• Hyperthermic Isolated Limb Perfusion (HILP).
• Clinical Trials.

Surgery

Surgery is the primary treatment for STS. The goal of surgery is to remove the whole tumor. The surgeon often removes a 2cm area of normal tissue around the tumor as well. In some cases, you may need an amputation (removal of a body part) to remove the cancer. There is a low risk of spread to lymph nodes, so lymph node dissection (removal of an area of lymph nodes) is not often done. In certain types of STS, lymph node involvement is more common (angiosarcoma and embryonal rhabdomyosarcoma). If lymph node involvement is suspected, these nodes may be removed. For patients with small, low-risk tumors, surgery might be the only treatment. However, most patients will also need radiation therapy.

Radiation Therapy

Radiation therapy is the use of high-energy x-rays to kill cancer cells. It can be done before or after surgery, or during surgery using brachytherapy (internal radiation). Treatment with radiation can stop the tumor from coming back (called recurrence) in the area of the original tumor better than surgery alone. Radiation used with limb-sparing surgery allows patients with STS in an extremity to avoid amputation.

Talk to your provider about if you should have radiation therapy before, during, or after surgery.

Chemotherapy

Chemotherapy is the use of anti-cancer medicine that goes through your whole body to kill cancer cells. It is often given IV (intravenously, in a vein) or by mouth (oral). Chemotherapy can be given before surgery (called neoadjuvant) to shrink the tumor enough to allow for a better removal of the tumor, or after surgery (called adjuvant). The main goal of adjuvant chemotherapy is to kill any cancer cells that can’t be seen in the body. These are the cells that can start to grow in other organs, most often the lungs.

Many patients will be cancer free after surgery and radiation alone. Because chemotherapy can cause side effects, it is important to limit chemotherapy treatment to patients at the highest risk for relapse (the cancer returning).

Chemotherapeutic medications used in the treatment of STS are doxorubicin, ifosfamide, epirubicin, gemcitabine, mesna, vinorelbine, docetaxel, trabectedin, vincristine, dactinomycin, cyclophosphamide, irinotecan, paclitaxel, bevacizumab, temozolomide, and dacarbazine. These medications can be used in combination or alone.

Targeted Therapy

Some types of STS may be treated with targeted therapies that focus on specific gene mutations or proteins in that tumor. Targeted therapies work by targeting something specific to a cancer cell, which lets the medication kill cancer cells and minimally affect healthy cells. Sometimes the “target” is found on a certain type of healthy cell and side effects can happen as a result. These medications are olaratumab, pazopanib, imatinib, palbociclib, crizotinib, ceritinib, sunitinib, nilotinib, dasatinib, regorafenib, larotrectinib, entrectinib, avapritinib and sorafenib. Other targeted and immune therapies are being studied in the treatment of soft tissue sarcomas.

Hyperthermic Isolated Limb Perfusion (HILP)

Hyperthermic Isolated Limb Perfusion (HILP) is used to treat STS in the extremities (legs or arms). Chemotherapy is given directly into the limb and circulation in and out of the limb is lessened. The limb's temperature is heated above normal temperatures. This technique makes the chemotherapy much stronger than giving it through a regular IV. HILP is being studied in patients who would otherwise need amputation or those who have a localized area of recurrence.

Clinical Trials

You may be offered a clinical trial as part of your treatment plan. To find out more about current clinical trials, visit the OncoLink Clinical Trials Matching Service.

Making Treatment Decisions

Your care team will make sure you are part of choosing your treatment plan. This can be overwhelming as you may be given a few options to choose from. It feels like an emergency, but you can take a few weeks to meet with different providers and think about your options and what is best for you. This is a personal decision. Friends and family can help you talk through the options and the pros and cons of each, but they cannot make the decision for you. You need to be comfortable with your decision – this will help you move on to the next steps. If you ever have any questions or concerns, be sure to call your team.

You can learn more about soft tissue sarcoma at OncoLink.org.