Test Details
Methodology
Next-generation sequencing to identify genetic variants, including single nucleotide variants (SNVs), insertions, deletions and copy number variants (CNVs).
Confirmation of the presence and location of reportable variants is performed as needed based on stringent criteria using one of several validated orthogonal approaches.1
Result Turnaround Time
10 - 14 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
This test includes the following genes: BRCA1, BRCA2, CDH1, PALB2, PTEN, STK11 and TP53.
Add-on breast cancer STAT genes ATM and CHEK2 can be included in the order via an ask on entry question (AOE).
Use
This test analayzes well-established genes that are associated with a significantly increased risk of developing breast cancer, and for which there are medically actionable, published, evidence-based management and risk-reduction options. It is appropriate for breast cancer patients with upcoming cancer-related breast surgeries and/or treatment where genetic testing may inform decisions such as lumpectomy versus mastectomy, single versus double mastectomy, or use of other treatments (such as PARP inhibitors or other chemotherapy regimens).
Depending on the individual’s clinical and family history, a broader panel may be appropriate.
This test is specifically designed for heritable germline mutations and is not appropriate for the detection of somatic mutations in tumor tissue.
Special Instructions
Test orders must include an attestation that the provider has the patient's informed consent for genetic testing.
Limitations
Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations, including rearrangements and gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants or repeat expansions.
Variant classification and/or interpretation may change with time if more information becomes available. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Whole blood or ORAcollect Dx OCD-100 buccal swabs
Volume
4 mL whole blood or 2 ORAcollect Dx OCD-100 buccal swabs
Minimum Volume
3 mL whole blood or 2 ORAcollect Dx OCD-100 buccal swabs
Container
Lavender-top (EDTA) tube or ORAcollect Dx OCD-100 buccal swabs
Collection Instructions
Standard phlebotomy; follow ORAcollect Dx OCD-100 buccal swab collection instructions. Do not eat, drink, smoke or chew gum 30 minutes prior to buccal collection.
Stability Requirements
- Whole blood: 90 days at room temperature or 4°C
- Buccal: 60 days at room temperature
Storage Instructions
For blood and buccal, maintain specimen at room temperature or refrigerate at 4°C. Do not freeze.
Causes for Rejection
Frozen or hemolyzed specimen; quantity not sufficient for analysis or in improper container; specimen from an individual who has undergone allogeneic bone marrow transplant
Footnotes
1. Lincoln SE, Truty R, Lin CF, et al. A Rigorous Interlaboratory Examination of the Need to Confirm Next-Generation Sequencing-Detected Variants with an Orthogonal Method in Clinical Genetic Testing. J Mol Design. 2019 Mar;21(2):318-329. PubMed 30610921