|
Test ID: KRAS
|
|
KRAS Mutation Analysis
|
|
KRAS mutation detection by Real Time - PCR
|
|
Useful For
|
The analysis of KRAS status is considered medically necessary to predict treatment responses and prognosis in several cancer types including colorectal adenocarcinoma, non-small cell lung cancer (NSCLC) and Pancreatic cancer.
|
|
Method name and description
|
This method is for the detection of the most common mutation in KRAS gene and it is performed by using Real Time PCR for KRAS mutation detecting in genomic DNA of patients diagnosed with metastatic colorectal or lung cancer. The following mutations are detected with 5% detection level: G12R, G12C, G12S, G12A, G12D and G13D in exon 2 of KRAS gene. Q61R, Q61H and Q61L in exon 3 of KRAS gene. K117N, K117R, K117E, A146T, A146P and A146V in exon 4 of KRAS gene.
Also, KRAS is tested by sequencing method in which exons 2, 3 and 4 of KRAS gene are amplified and sequenced for detection and confirmation of the KRAS mutation if required.
|
|
Reporting name
|
KRAS mutation analysis
Detected: indicates presence of KRAS mutation.
No mutation detected: indicates absence of KRAS mutation.
|
|
Clinical information
|
KRAS is an important predictive and prognostic marker in colon cancer. Approximately 30-50% of colorectal tumors are known to have a mutated KRAS gene, indicating that up to 50 % of patients with colorectal cancer (CRC) might respond to anti-epidermal growth factor receptor (EGFR) antibody therapy. However, 40-60 % of patients with wild-type KRAS tumors do not respond to such therapy. KRAS mutated tumors are associated with poor prognosis and are presently excluded from anti-EGFR therapy.
KRAS mutations were reported cause resistance to EGFR TKI therapy (AACR Project GENIE. Cancer Discovery. 2017). Recently, A new drug application has been submitted for FDA approval. Sotorasib (formerly AMG 510) for the treatment of patients with KRAS G12C–mutant locally advanced or metastatic non–small cell lung cancer (NSCLC). Sotorasib was the first KRAS to be approved targeted therapy as G12C inhibitor for patients with advanced NSCLC harboring the KRAS G12C mutation (Amgen's Sotorasib Granted Breakthrough Therapy Designation For Advanced Or Metastatic Non-Small Cell Lung Cancer Patients With KRAS G12C Mutation, published December 8, 2020).
|
|
|
Specimen type / Specimen volume / Specimen container
|
FFPE tissue:
Option 1: Tissue sections of 10X (5-7 µm) fixed on non-charged slides with an H&E stained slide with marked tumor area.
Option 2: Tissue curls of 6 sections (10 µm) collected in 2 mL tube (e.g. Eppendorf).
|
|
Collection instructions / Special Precautions / Timing of collection
|
Specimens are arranged from Sunday to Wednesday from the Anatomical Pathology Department to the Molecular Genetics Laboratory at room temperature.
Please avoid direct sun light exposure.
|
|
Relevant clinical information to be provided
|
The following points must be provided:
- The tumor rich area on the must be marked by a consultant pathologist.
- Tumor percentage.
- Cancer type.
|
|
Storage and transport instructions
|
The specimens are stored and transported at Room Temperature (16 - 25° C).
|
|
Specimen Rejection Criteria
|
Consistent with Diagnostic Genomic Division policies
|
|
|
Biological reference intervals and clinical decision values
|
For Real Time - PCR: Detected amplifications of the mutant target with mutant allele frequency >5% are refered as Detected.
No amplification of the mutant allele due to low mutant allele frequency (<5%) or due to absence of mutant target are referred as No mutation detected.
For DNA sequencing: the lower limit of detection is >20%.
|
|
Factors affecting test performance and result interpretation
|
This test was validated for DNA extraction from FFPE, the FFPE process has effect on the DNA quality and might result on DNA degradation. In addition, PCR inhibitors due to FFPE fixation might affect the PCR amplification.
|
|
Turnaround time / Days and times test performed / Specimen retention time
|
Days Test is Performed
Arranged by laboratory Rota.
TAT :
Single gene testing: 10 working days.
Reflex testing: 10 working days for the first test and an additional week (5 working days) for every following test.
|
|
|
