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Test Code KRASW KRAS Somatic Mutation Analysis, Peritoneal Fluid


Shipping Instructions


 



Necessary Information


1. A pathology report (final or preliminary) is required and must accompany specimen for testing to be performed.

2. The following information must be included in the report provided.

-Patient name and second identifier

-Date of fluid collection

-Source of the fluid



Specimen Required


Container/Tube: 50-mL Falcon tube

Preferred: Fresh, peritoneal washing; no fixatives added to wash

Specimen Volume: Two 50-mL Falcon tubes

Collection Instructions: Containers must be labeled with two unique patient identifiers.


Useful For

Staging of the pancreatic ductal adenocarcinoma(1)

Disease States

  • Colorectal cancer

Method Name

Droplet Digital Polymerase Chain Reaction (ddPCR)

Reporting Name

KRAS Mutation Analysis, Peritoneal

Specimen Type

Peritoneal

Specimen Minimum Volume

100 mL of peritoneal washing

Specimen Stability Information

Specimen Type Temperature Time Special Container
Peritoneal Refrigerated (preferred) 10 days
  Ambient  5 days

Reject Due To

Fixative added Reject

Clinical Information

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with predilection for peritoneal dissemination. Accurate peritoneal staging is important for management of patients with PDAC. The KRAS oncogene is the most frequently mutated oncogene in PDAC. Detection of KRAS mutations within peritoneal fluid has been associated with clinically positive laparoscopic findings (gross metastases and/or positive peritoneal cytology) and elevated peritoneal fluid carbohydrate antigen 19-9 and/or carcinoembryonic antigen and may portend an increased risk of residual/recurrent pancreatic cancer metastases within the peritoneal cavity.

 

This test uses DNA extracted from cells shed into the peritoneum to evaluate for the presence of KRAS (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T) mutations. A positive result indicates the presence of an activating KRAS mutation and can be a useful marker to aid in the staging of pancreatic ductal adenocarcinoma.

Reference Values

An interpretive report will be provided.

Interpretation

The interpretation of molecular biomarker analysis includes an overview of the results and the associated diagnostic, prognostic, and therapeutic implications.

Cautions

Patients with a negative test result may still harbor a KRAS mutation below the level of detection.

 

The limit of detection of this assay is influenced by the amount of cells and DNA in the peritoneal wash. This is a biological variable that cannot be controlled.

 

This assay was designed to detect mutations in KRAS codons 12, 13, 61, and 146 (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T).

 

This test has not been clinically validated for use as a tool to monitor response to therapy or for early detection of tumors.

 

This test cannot differentiate between somatic and germline alterations.

Clinical Reference

1. Yonkus JA, Alva-Ruiz R, Abdelrahman AM, et al. Molecular peritoneal staging for pancreatic ductal adenocarcinoma using mutant KRAS droplet-digital polymerase chain reaction: Results of a prospective clinical trial. J Am Coll Surg. 2021;233(1):73-80.e1. doi:10.1016/j.jamcollsurg.2021.05.009

2. Kim NH, Kim HJ. Preoperative risk factors for early recurrence in patients with resectable pancreatic ductal adenocarcinoma after curative intent surgical resection. Hepatobiliary Pancreat Dis Int. 2018;17(5):450-455 doi:10.1016/j.hbpd.2018.09.003

3. Avula LR, Hagerty B, Alewine C. Molecular mediators of peritoneal metastasis in pancreatic cancer. Cancer Metastasis Rev. 2020;39(4):1223-1243. doi:10.1007/s10555-020-09924-4

Method Description

Droplet digital polymerase chain reaction is used to test for the presence of KRAS codon 12, 13, 61, and 146 mutations.(Yonkus JA, Alva-Ruiz R, Abdelrahman AM, et al. Molecular peritoneal staging for pancreatic ductal adenocarcinoma using mutant KRAS droplet-digital polymerase chain reaction: Results of a prospective clinical trial. J Am Coll Surg. 2021;233[1]:73-80.e1. doi:10.1016/j.jamcollsurg.2021.05.009)

Day(s) Performed

Monday through Friday

Report Available

5 to 10 days

Specimen Retention Time

Extracted DNA: 3 months

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

81275-KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene) (eg, carcinoma) gene analysis, variants in codons 12 and 13

81276-KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene) (eg, carcinoma) gene analysis, additional variants

LOINC Code Information

Test ID Test Order Name Order LOINC Value
KRASW KRAS Mutation Analysis, Peritoneal 21702-6

 

Result ID Test Result Name Result LOINC Value
616453 Result Summary 50397-9
616454 Result 82939-0
616455 Interpretation 69047-9
616456 Specimen 31208-2
616457 Source 31208-2
616459 Released By 18771-6
616460 Method 85069-3
616461 Disclaimer 62364-5
616462 Additional Information 48767-8

NY State Approved

Yes