Microsatellite Instability (MSI)

The Microsatellite Instability (MSI) test is a molecular diagnostic test that evaluates the stability of short, repetitive DNA sequences known as microsatellites. Normally, the body’s DNA mismatch repair (MMR) system corrects any errors that occur during DNA replication. However, if there are mutations or defects in the MMR genes, these errors accumulate, leading to microsatellite instability (MSI).

This instability is often associated with Lynch syndrome (Hereditary Non-Polyposis Colorectal Cancer or HNPCC), which is the most common inherited cause of colorectal cancer. It can also increase the risk of developing other cancers, such as endometrial, stomach, ovarian, and urinary tract cancers.

The Microsatellite Instability (MSI) test is performed using Polymerase Chain Reaction (PCR) technology, which analyzes tumor tissue samples to detect unstable microsatellite regions. Identifying MSI helps in diagnosing Lynch syndrome and determining the most suitable treatment approach. It also helps doctors identify patients who may respond well to targeted immune therapy (such as Pembrolizumab) and in planning early cancer screening or preventive strategies for at-risk family members.

Doctors may recommend the Microsatellite Instability (MSI) test when a person presents with symptoms or tumors suggestive of Lynch syndrome or has a personal or family history of related cancers such as colorectal, endometrial, or ovarian cancer. It also helps identify individuals who may benefit from targeted immune therapy using Pembrolizumab, a drug used to treat certain advanced cancers. Additionally, the MSI test can assist doctors in assessing the effectiveness of treatment for Lynch syndrome-related tumors and guide personalized management strategies for patients and their families.

For this test, it is important to submit the clinical history, histopathology report, previous test results, and a doctor’s prescription at the time of sample collection. The Tata 1mg consolidated Test Requisition Form (TRF) must also be duly filled and submitted.

Lab test results may vary across different laboratories. Abnormal test results require an expert interpretation. Therefore, never try to self-medicate at home based solely on these results, and always consult a doctor for a proper understanding of the test results.

Disclaimer: In no event shall the liability of TATA 1MG exceed the amount of the actual cost of test charges incurred by the customer as stated on the invoice issued by Tata 1mg.