380 likes | 529 Views
Molecular Pathology Tests: Choosing Among the Many. Jennifer Laudadio, MD University of Arkansas for Medical Sciences. Disclosures. None. Objectives. Assess appropriateness of molecular testing requests and decide among the available methods
E N D
Molecular Pathology Tests:Choosing Among the Many Jennifer Laudadio, MD University of Arkansas for Medical Sciences
Disclosures • None
Objectives • Assess appropriateness of molecular testing requests and decide among the available methods • Evaluate quality and cost-effectiveness of testing options when deciding which ones to bring in-house
THE 3PM PHONE CALL (OR EMAIL)
What Now? • The test you know absolutely nothing about • The test you know about but don’t know if the methodology matters and don’t know where to send it • The test you know all about but don’t know where to send it • The test request you know how to handle – EASY, DONE
The test you know nothing about • Spend a couple of hours researching the test • Knock on your colleagues door • Ask your colleague requesting the test to send you information • Check reference lab test menus • Check www.amp.org test menu
The test you know nothing about • Is this medically necessary? • What is the cost? • Has the requesting doctor talked to the patient about this super expensive test? • Do multiple labs offer the test? • Do all labs use the same test method?
Example “That test that tells me where the primary tumor is”
What tests are available? • Biotheranostics • Pathwork Diagnostics • Rosetta Genomics
Biotheranostics • CancerType ID • Laser micro-dissection (need special slides) • Real Time RT-PCR • 92 genes 87 tumor associated 5 reference • Classifies 50 cancer types/subtypes 87% accurate for 28 main tumor types 82% accurate for 50 subtypes
Pathwork Diagnostics • Tissue of Origin Test • DNA based expression array • ~2000 genes • Classifies 15 primary types/ 58 morphologies • 89% positive agreement • FDA-cleared for formalin fixed paraffin embedded tissue
Rosetta Genomics • miRview Mets 2 • Expression levels of micro-RNAs • 64 micro-RNAs • Classifies 42 tumor types • 85% sensitivity
What tissue is available for testing?What are the specimen requirements for each test? • Specimen size? • Tumor cellularity? • Decalcified? • Test methodology can impact what sample is acceptable.
Is each test equally “good”? • Monzon FA and Koen TJ. Diagnosis of metastatic neoplasms: molecular approaches for identification of tissue of origin. Arch Pathol Lab Med. 2010; 134(2):216-224.
Shipping Requirements?Don’t forget about the $$! • Does the company direct patient/insurance bill? • What is the cost of the test? • Has the oncologist discussed this test with the patient?
The test you know nothing about • Yes, there will be preliminary information gathering necessary • Ask the requesting oncologist for information • Ask your colleagues if they have had any experience with any of the tests and what they thought • Yes, the second time you get this request, it will go much smoother
The test you have heard about • Method? • Probably the hardest part • Intro to molecular methods CME • Webinars • Which reference lab? • Specimen requirements? • Test the primary or metastasis?
Example KRAS mutation testing for metastatic colorectal carcinoma
Methodology • Sensitivity • Specific codons targeted by the method • Examples of methods used for KRAS testing • Sequencing • Pyrosequencing • Allele specific PCR
KRAS Methodology • Sequencing • Get information on entire exon • Need at least 20% mutant allele • Does lab inhibit wild type alleles to increase sensitivity? • Pyrosequencing • Improves sensitivity • Targets specific mutations • Special instrumentation • Allele specific PCR • Targets specific codon 12 and 13 point mutations • Sensitivity down to ~1% mutant allele • Is it too sensitive?
Specimen Requirements and Selecting a Reference Lab • FFPE acceptable • Block • Unstained slides (don’t have to be charged) • Test either the metastasis or primary • The usualreference lab • all our reference testing has to go to lab X • Search for a reference lab • Google reference lab test menus • Mayo Test Menu • Get info on methodology, specimen requirements, clinical utility, access requisition form, etc
Proactive • You make that phone call to recommend a test • Reflex testing policy
You recommend a test You diagnose metastatic colorectal carcinoma in a liver biopsy – call surgeon or oncologist and ask if they want it sent for KRAS testing.
Reflex Testing HPV for oropharyngeal squamous cell carcinomas
Establishing a Reflex Testing Policy • Communication • Requests from clinicians • Agreement among Pathologists • Methodology • How to get a reflex testing policy approved? • Medical Center Dependent • How to communicate the new policy once approved • Monitor adherence
Specifics from experience with HPV • Multi-disciplinary requests ENT surgeons Medical oncologist Radiation oncologist • Indications Prognostic and Predictive Diagnostic
Specifics from experience with HPV • Choosing a Methodology • In situ hybridization • High specificity • Low sensitivity • PCR • High sensitivity • Is it too sensitive? • P16 • Surrogate • High sensitivity • Lower specificity In situ hybridization p16 IHC
Specifics from experience with HPV • Drafting a Reflex Policy • Specific Diagnoses that would trigger the reflex test • CPT codes • Getting the Policy Approved • Communicating the Policy
You want to get into the Molecular Diagnostics Game What tests to bring in house?
Type of equipment and expertise needed? • FDA approved tests Require less expertise Expense Verification of performance characteristics • Lab Developed tests Time for development Expertise More rigorous validation
What’s Realistic • Dedicated Research/Development person One test a month • Pathologists also involved in patient care 3-4 tests per year • Don’t forget the need for IT support!!
Will I get paid? • New CPT codes Based on analyte being tested Not method specific Replace “stacking” codes On clinical lab fee schedule G code for professional interpretation • Gap-fill method of determining reimbursement • Critical time to work with payers
Take Home Points • Yes, it can be taxing to your practice to evaluate molecular testing requests. • You can handle these requests either proactively or reactively • Reactive is not necessarily bad • Take advantage of the resources around you – the requesting MD, other pathologists, On-line test menus, Google, webinars, CME
Take Home Points: Examples of Tests • Tests for tumor of unknown origin • Medical necessity • Methodology and Targeted genes • Specimen Requirements • KRAS • Methodology and Mutation targets • Finding a reference lab • Mets versus Primary • HPV • Developing a reflex testing policy • Selecting a method
Take Home Points • A basic understanding of molecular techniques may prove useful • Deciding to bring tests in-house • FDA-approved versus lab developed • Performance Characteristics • Cost • Expertise necessary