Test Code ESR1T ESR1 Mutation Analysis, Next-Generation Sequencing, Tumor
Ordering Guidance
Multiple oncology (cancer) gene panels are available. For more information see Hematology, Oncology, and Hereditary Test Selection Guide.
Necessary Information
A pathology report (final or preliminary), at minimum containing the following information, must accompany specimen for testing to be performed:
1. Patient name
2. Block number-must be on all blocks, slides, and paperwork (can be handwritten on the paperwork)
3. Tissue collection date
4. Source of the tissue
Specimen Required
This assay requires at least 20% tumor nuclei.
NOTE: Submit tissue from either local recurrence or metastatic disease collected after endocrine therapy has been administered (see Clinical Information for more details).
-Preferred amount of tumor area with sufficient percent tumor nuclei: tissue 216 mm(2)
-Minimum amount of tumor area: tissue 36 mm(2)
-These amounts are cumulative over up to 10 unstained slides and must have adequate percent tumor nuclei.
-Tissue fixation: 10% neutral buffered formalin, not decalcified
-For specimen preparation guidance, see Tissue Requirement for Solid Tumor Next-Generation Sequencing. In this document, the sizes are given as 4 mm x 4 mm x 10 slides as preferred: approximate/equivalent to 144 mm(2) and the minimum as 3 mm x 1 mm x 10 slides: approximate/equivalent to 36 mm(2).
Preferred:
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue.
Acceptable:
Specimen Type: Tissue slides
Slides: 1 Stained and 10 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 10 unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.
Note: The total amount of required tumor nuclei can be obtained by scraping up to 10 slides from the same block.
Additional Information: Unused unstained slides will not be returned.
Specimen Type: Cytology slides (direct smears or ThinPrep)
Slides: 1 to 3 Slides
Collection Instructions: Submit 1 to 3 slides stained and coverslipped with a preferred total of 5000 nucleated cells, or a minimum of at least 3000 nucleated cells.
Note: Glass coverslips are preferred; plastic coverslips are acceptable but will result in longer turnaround times.
Additional Information: Cytology slides will not be returned.
Useful For
Assisting in the clinical management of patients with metastatic breast cancer by identifying tumors with evolving resistance to endocrine therapy
Stratifying prognosis of metastatic breast cancer
Disease States
- Breast cancer
Special Instructions
Method Name
Sequence Capture and Targeted Next-Generation Sequencing (NGS)
Reporting Name
ESR1 Mutations Analysis, TumorSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Ambient (preferred) | ||
Refrigerated |
Reject Due To
Specimens that have been decalcified (all methods) Specimens that have not been formalin-fixed, paraffin-embedded, except for cytology slides Extracted nucleic acid (DNA/RNA) |
Reject |
Clinical Information
The ESR1 (estrogen receptor 1) gene encodes an estrogen receptor that regulates cell growth through activation of downstream signaling pathways upon binding of estrogen. Tumors demonstrating estrogen receptor expression by immunohistochemistry (ER-positive) are candidates for endocrine therapy, such as selective estrogen receptor modulators (SERM), selective estrogen receptor degraders/downregulators (SERD), and aromatase inhibitors. ESR1 mutations are rarely observed in untreated breast cancers; however, mutations in the ligand-binding domain of ESR1 can occur secondarily after exposure to aromatase inhibitors and other endocrine therapies in ER-positive metastatic breast tumors, frequently with multiple different mutations in ESR1 occurring together. Current data suggests that ESR1 mutations mediate resistance to endocrine therapy. Studies also suggest that ESR1 mutations are an independent indicator of poor prognosis.
This test assesses for somatic mutations in ESR1, including the ligand-binding domain(exons 4-9 in reference transcript NM_001122740). Breast cancers with mutations in the ligand binding domain of ESR1 may be responsive to elacestrant (Orserdu), an endocrine therapy in the SERD class of drugs that is clinically approved for postmenopausal women or adult men with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
Report Available
12 to 20 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest 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
88381 - Microdissection, manual
81479
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.