dMMR Endometrial Cancer Treatment: Understanding Your Options

Some people with endometrial cancer have a specific subtype called dMMR. This stands for “deficient mismatch repair.” It means cells have trouble fixing DNA damage. Cancers with dMMR tend to have many DNA errors, which can make tumors grow and spread more quickly.¹

For people with dMMR endometrial cancer, previous treatments may not have worked, or the cancer may have returned after previous treatment (recurrent cancer), or spread to other parts of the body (metastatic). The cancer is typically considered advanced at this point.^1,2

Treating dMMR endometrial cancer can be a challenge, but there are several options for managing the disease and improving quality of life, and treatment options continue to improve. dMMR endometrial cancer treatment is based on:^1-3

• The stage of the cancer
• Previous endometrial cancer treatment
• Your age and overall health
• Personal treatment preferences

What does surgery for this cancer involve?

Surgery is generally the first step in treating endometrial cancer. For advanced cases, doctors may recommend removing a total hysterectomy bilateral salpingo-oophorectomy, or TH/BSO for short— in simpler terms, a surgery to remove the uterus, fallopian tubes, and ovaries. Nearby lymph nodes also may be removed to check whether the cancer has spread to them.³

Surgeons sometimes also remove visible cancer in other parts of the body. This is known as debulking surgery. Its goal is to reduce the amount of cancer, which can make other treatments like chemotherapy or radiation more effective.³

Surgery may not be an option for everyone, especially those with recurrent or metastatic endometrial cancer. If the cancer has spread widely, or if the person is too ill to undergo surgery, doctors may explore other treatment options.³

How does chemotherapy help treat advanced disease?

Chemotherapy ("chemo") uses drugs to kill cancer cells or stop them from growing. This treatment is often recommended for advanced endometrial cancer, especially if the disease has spread to distant parts of the body.^3,4

Chemotherapy is usually given through an IV or a pill. It can be used alone, but it is often more effective when combined with other chemo drugs. It is typically given in cycles, with rest periods in between, to allow the body to recover.^3,4

In advanced endometrial cancer, the goal of chemo is often to control the disease and slow its progression. This treatment can be effective for shrinking tumors and reducing the chance of the cancer spreading.^3,4

What types of radiation therapy are used and when?

Radiation therapy uses high-energy rays to target and destroy cancer cells. It is often used after surgery to kill any remaining cancer cells or to treat areas where the cancer has spread. There are 2 main types of radiation therapy for endometrial cancer:^1,3,5

• External beam radiation: delivers radiation from a machine outside the body.
• Brachytherapy: places radioactive sources inside the body, near the cancer.

In advanced cases, radiation therapy may be used in combination with chemotherapy.⁴

How is targeted therapy different?

Targeted therapy is a newer approach to treating cancer. It focuses on specific molecules or processes that cancer cells use to grow and spread. While chemotherapy affects both cancer cells and healthy cells, targeted therapy is designed to attack only cancer cells and while minimizing the impact on healthy cells. This can lead to fewer side effects than chemotherapy.⁶

Doctors may recommend targeted therapy for certain types of high-risk endometrial cancer. This treatment may be used in combination with other therapies and is chosen based on the characteristics of the cancer. Some of these therapies may require special testing to see if you are eligible.⁶

How does immunotherapy work?

Immunotherapy is often used when other treatments have not worked or for recurrent cancers. Immunotherapy is a treatment that uses your own immune system to fight cancer, helping it recognize and attack cancer cells.^1,2,7

Several immunotherapy drugs are available to treat advanced endometrial cancer, and more are being studied. Immunotherapy may be combined with chemo or targeted therapy drugs in certain situations.^1,2,7

Can hormone therapy help preserve fertility?

Hormone therapy is used to slow the growth of certain types of endometrial cancer cells. It can be given as pills or injections and is often combined with another treatment, like chemotherapy.⁸

Hormone therapy can be used for endometrial cancer that has spread or returned after initial treatment. It may also be an option for women with endometrial cancer who want to get pregnant in the future, since hormone therapy may help preserve their fertility.⁸

How do you decide which dMMR endometrial cancer treatment is right for you?

Choosing the right treatment for advanced endometrial cancer involves careful consideration. A team that may include oncologists, surgeons, and other specialists will work together to create a personal treatment plan for you.^2,3

Ideally, your doctor will discuss the goals of treatment along with each treatment’s potential benefits, possible side effects, and risks. You should feel comfortable asking questions and sharing your preferences. Support from family, friends, and community groups can also be helpful during this time.

Is there hope for better outcomes in the future?

Research in dMMR endometrial cancer treatment continues to improve. Precision-based therapies and clinical trials offer hope for better survival rates. While more work is needed, researchers agree that a personalized approach is key to improving outcomes.^1,2