Trastuzumab Deruxtecan (T-DXd) is a medication that targets cancer cells with a protein called HER2 on their surface. It works by attaching to these HER2 proteins and delivering a cancer-killing drug directly into the cancer cells.

Rilvegostomig is a medication that helps boost the body’s immune system to fight cancer cells. It works by helping the immune system recognize and attack cancer cells more effectively.

Pembrolizumab is an immunotherapy medication that helps the body’s immune system detect and fight cancer cells. It works by blocking a protein called PD-1, which normally prevents the immune system from attacking cancer cells.

Carboplatin is a chemotherapy medication that works by interfering with the DNA in cancer cells, preventing them from growing and multiplying.

Paclitaxel is a chemotherapy medication that works by stopping cancer cells from dividing and growing. It disrupts the structural framework inside cancer cells that allows them to divide.

Endometrial Cancer Endometrial cancer is a malignancy that develops in the lining of the uterus (endometrium). It typically begins with abnormal cell growth in the endometrial tissue, which can eventually form a tumor. The disease often develops slowly, starting as endometrial hyperplasia before potentially progressing to cancer. As it advances, endometrial cancer can spread locally within the pelvis, and in later stages may metastasize to distant organs such as the lungs or liver. In recurrent cases, the cancer returns after a period of remission, either in the same location or elsewhere in the body.

HER2-Expressing Endometrial Cancer This subtype of endometrial cancer is characterized by overexpression of the HER2 protein on cancer cell surfaces. HER2 (Human Epidermal Growth Factor Receptor 2) is a protein that promotes cell growth, and when overexpressed, can lead to more aggressive cancer behavior. In pathology, this is identified as either strongly positive (IHC 3+) or moderately positive (IHC 2+) using immunohistochemistry testing. HER2-expressing endometrial cancers may have distinct growth patterns and cellular characteristics compared to non-HER2 expressing types.

Mismatch Repair Proficient (pMMR) Endometrial Cancer This refers to endometrial cancer that has functioning DNA mismatch repair proteins. Mismatch repair is a cellular process that corrects errors during DNA replication. In pMMR endometrial cancer, this repair system works normally, as opposed to deficient mismatch repair (dMMR) tumors. pMMR endometrial cancers typically have fewer mutations overall compared to dMMR tumors. This molecular classification helps define the biological behavior of the tumor and its progression pattern.