Rawia Mohamed: The benefits of the MMR IHC test

Rawia Mohamed, Head of the anatomical pathology department at Burjeel Medical City, shared on LinkedIn:

“MMR (Mismatch Repair) immunohistochemistry (IHC) is a laboratory test used to assess the status of the mismatch repair genes in a tissue sample, typically from a tumor.

The mismatch repair system is responsible for correcting errors that occur during DNA replication, and its dysfunction can lead to the development of certain types of cancer.

The benefits of the MMR IHC test include:

1. Identifying Microsatellite Instability (MSI):
– MMR IHC can help determine if a tumor has a high degree of microsatellite instability (MSI-H), which is a characteristic of certain types of cancer, such as colorectal and endometrial cancer.
– MSI-H tumors often have a better prognosis and may respond differently to certain cancer treatments compared to microsatellite-stable (MSS) tumors.

2. Hereditary Cancer Screening:
– The MMR IHC test can help identify individuals with a germline mutation in one of the mismatch repair genes, such as MLH1, MSH2, MSH6, or PMS2.
– This information can be used to screen for and potentially prevent hereditary forms of cancer, such as Lynch syndrome, which is associated with an increased risk of colorectal, endometrial, and other cancers.

3. Therapeutic Implications:
– The MMR IHC test can help guide treatment decisions, as some cancer therapies, such as immune checkpoint inhibitors, may be more effective in MSI-H tumors.
– Knowing the MMR status can help healthcare providers choose the most appropriate treatment plan for the patient.

4. Prognostic Information:
– MMR IHC results can provide prognostic information, as MSI-H tumors are generally associated with a better prognosis compared to MSS tumors in certain cancer types.”

Source: Rawia Mohamed/LinkedIn