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KRAS Sequencing
| Item | Value |
|---|---|
| Approval req'd? | No |
| Available Stat? | No |
| Test code | Test is ordered in CoPath |
| Performed by | Molecular Diagnostics |
| In House Availability | Run 1x per week, DNA extraction started on Monday, day shift only |
| Method | The KRAS Mutation Testing by Sequencing assay utilizes PCR amplification and dye termination sequencing of exon 2 of the KRAS gene using specific PCR primers. DNA is extracted from tumor tissue and amplified in a PCR reaction. After DNA cleanup to remove primers, the amplified product is sequenced bidirectionally using dye termination cycle sequencing. The sequencing products are separated by capillary electrophoresis and analyzed for mutations in codons 12 and 13. |
| Collection Instructions | Blocks selected for KRAS mutation testing must contain tumor tissue. Areas of tumor must contain at least 50% tumor cells. The lab can remove adjacent non-tumor tissue, so the entire slide does not need 50% tumor cells, just the area with tumor. Label slides with pathology case number and block identification. For UCSF Samples (from remote sites) Click here for sample collection instructions For NON-UCSF Samples Click here for Requisition form & Account set-up instructions. Note we only do institutional billing. |
| Container type | |
| Sample type | Formalin-fixed, paraffin-embedded 10 micron tissue sections on five (5) unstained, uncharged glass slides. One adjacent H&E stained slide should be included. |
| UCSF Rejection Criteria | All required slides not included. Insufficient tumor tissue present on slide as determined by pathologist. Slides not labeled or not accompanied by completed requisition form (if not ordered directly through Department of Pathology). |
| Normal range | Negative for KRAS mutations at codons 12 and 13. |
| Synonyms | K-RAS |
| Stability | Formalin-fixed, paraffin-embedded tissues are stable indefinitely at room temperature |
| Turn around times | 10-14 days |
| Additional information | Exon 2 of the KRAS gene, including codons 12 and 13, is sequenced to look for mutations in either one of these two codons. These are the most commonly reported KRAS mutations in lung and colorectal cancers. Mutations of these codons have been shown to be predictive of resistance to EGFR-directed therapy in patients with non-small cell lung cancer and metastatic colorectal cancer. Results of this test should be correlated with the patient's other clinical and laboratory information. This assay is not intended to test for KRAS mutations outside of codons 12 and 13. The test was validated by UCSF Clinical Laboratories to confirm performance characteristics, in compliance with current guidelines for clinical implementation. |
| CPT coding | 81275 |
| LDT or Mod FDA? | Yes |
| Last Updated | 3/13/2013 9:04:22 AM |
| Entry Number | 1300 |
If you have additional questions regarding this test, please call: 415-353-1667