Skip to main content

ACS & ASCO are Stronger Together: Cancer.Net content is now available on



Immunotherapy for Uterine Sarcomas

Immunotherapy uses medicines to boost a person’s own immune system to recognize and destroy cancer cells more effectively. Immunotherapy typically works on specific proteins involved in the immune system to enhance the immune response. Side effects of these drugs are different from those of chemotherapy.

Some immunotherapy drugs, for example, monoclonal antibodies, work in more than one way to control cancer cells and may also be considered targeted drug therapy because they block a specific protein on the cancer cell to keep it from growing.

Immunotherapy is used to treat some types of uterine sarcomas.

Immune checkpoint inhibitors for uterine sarcomas

An important part of the immune system is its ability to keep itself from attacking normal cells in the body. To do this, it uses proteins (or "checkpoints") on immune cells that need to be turned on (or off) to start an immune response. Drugs that block these checkpoint proteins, (called immune checkpoint inhibitors) might be used to treat some uterine sarcomas.

PD-1 inhibitor

Pembrolizumab (Keytruda) is a drug that targets PD-1 (a protein on immune system T cells that normally helps keep them from attacking other cells in the body). By blocking PD-1, these drugs boost the immune response against cancer cells. This can often shrink tumors or slow their growth.

Pembrolizumab might be an option to treat some advanced uterine sarcomas, typically after other treatments have been tried or when no other good treatment options are available, and if the cancer cells have a high tumor mutational burden (TMB-H), meaning the cancer cells have many gene mutations. The tumor cells can be tested for these gene changes.

This drug is an intravenous (IV) infusion and is typically given every 3 or 6 weeks.

Possible side effects of immune checkpoint inhibitors

Side effects of these drugs can include fatigue, cough, nausea, skin rash, poor appetite, constipation, and diarrhea.

Other, more serious side effects occur less often.

Infusion reactions: Some people might have an infusion reaction while getting these drugs. This is like an allergic reaction, and can include fever, chills, flushing of the face, rash, itchy skin, feeling dizzy, wheezing, and trouble breathing. It’s important to tell your doctor or nurse right away if you have any of these symptoms while getting these drugs.

Autoimmune reactions: These drugs remove one of the protections on the body's immune system. Sometimes the immune system starts attacking other parts of the body, which can cause serious or even life-threatening problems in the lungs, intestines, liver, hormone-making glands, kidneys, or other organs.

It’s very important to report any new side effects to your health care team quickly. If serious side effects do occur, treatment may need to be stopped and you may get high doses of corticosteroids to suppress your immune system.

More information about immunotherapy

To learn more about how drugs that work on the immune system are used to treat cancer, see Cancer Immunotherapy.

To learn about some of the side effects listed here and how to manage them, see Managing Cancer-related Side Effects.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Alektiar KM, Abu-Rustum NR, and Fleming GF. Chapter 75- Cancer of the Uterine Body. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.

National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology. Uterine Neoplasms, Version 1.2022 – November 4, 2021. Accessed at on June 16, 2022.

Last Revised: September 20, 2022

American Cancer Society Emails

Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society.