Clinical Utility
MSI occurs in approximately 15% of CRC patients and more frequently in stage II (~20%) compared to stage III (~11%) and stage IV (~3.5%) CRCs. Nevertheless, MSI has also been observed in other types of cancer as shown in the following table.
| Cancer | MSI Prevelance | Histology |
|---|---|---|
| Breast | <%1, unless occuring in young women with HNPCC | - |
| Cervical | %5 | Advanced Cancers |
| Colorectal cancer | %15 | All cancers |
| Endometrial | Up to %33' | 40% of endometrioid tumours and 2% of serous tumours. |
| Gastric | %15 | All cancers |
| Glioma | %0-33 | Controversial data. Pediatric, young adults |
| Head and Neck Cancer | None | - |
| Hepatocellular | <%1 | - |
| Lung Cancer | <%1 | - |
| Melanoma | %2-77 | Inconsistent data |
| Ovarian | %10 | All cancers |
| Pancreatic and Periampullary | %1 in sporadic PDAC, %10 in cancers of periampullary area | All cancers |
| Prostate Cancer | Up to %12 | Advanced stage cancers |
| Renal cell carcinoma | None | - |
| Sarcoma | None | - |
| Sebaceous skin tumors | %25 | All cancers |
| Thyroid | %1 | All cancers |
The knowledge of the MSI status is valuable for:
- Determination of prognosis of Stage II Colon Cancer patients.
- Identification of patients with a higher risk of developing Hereditary Non Polyposis Colorectal Cancer (Lynch Syndrome).
- Identification of patients eligible for OncotypeDX® Colon.
- Prediction of 5-FU treatment.
- Response to immunotherapy.
