The end of each year brings with it the need to look back to achievements and significant events.  Newspapers and journals are putting forward their selections for “Man of the Year” or “Molecule of the Year” and publishing their lists of top this and top that.   I have been wondering what achievement or test AMP would identify as singularly outstanding or significant for our practice in 2008. What might be the AMP “Test of the Year”? 

Testing for JAK2 mutations as part of the diagnostic criteria for the myeloproliferative disorders comes to mind, but some might argue that this test had its “fifteen minutes” of fame in 2007.  Testing for KRAS might be a better choice.  The oncogene had been largely relegated to research laboratories for years until reports in early 2008 that KRAS mutation status is predictive of response to EGFR targeted monoclonal antibodies when used for the treatment of colon cancer.  If KRAS is in the lead, EGFR mutation testing must not be far behind.  Genomic “copy number variations” were a hot topic at our Annual Meeting in Texas last year, but does not strike me as ready for prime time.

My nomination for AMP Test of the Year will be the lowly LDT - the Laboratory Developed Test.  It is time to recognize the significance of the LDT and the contribution it has made to the advancement of medicine into the age of molecular biology, the introduction of molecular genetics into the clinic, and the exciting possibilities of personalized medicine that we, as physicians and laboratorians, labor to bring to our patients.  It is the LDT that allows us to translate the latest discoveries of the research laboratory into practical, useful clinical tests.

Try to envisage where the field of molecular pathology, indeed molecular medicine, would be today without the nimble LDT.  How many years would we have had to wait for commercial vendors to develop the molecular assays we currently have?   I will venture to say that most commercial assays were only pursued after their development and feasibility had been assured as LDTs.  The inroads we have made into practical molecular medicine, into personalized medicine, have at their origins the Laboratory Developed Test:  no LDT… no molecular medicine.  Furthermore, the LDT embodies all that we do and stand for as professionals.  It is our responsibility to provide only the highest quality of testing available to our patients, and our LDT’s are subject to no lesser standard.  If anything, the scrutiny we bring to these novel diagnostic assays exceeds anything required by the regulatory authorities.  As pathologists, as laboratorians, we understand analytical validity and clinical validity.  We live by clinical utility and indeed, serve as the mediators and gatekeepers, between the tests and the clinicians who use them.  We know what proficiency testing is and we make it work, and test standardization is what AMP is all about.  These are the things we do every day, as a matter of course.  To suggest that our LDTs are somehow inferior because they are regulated differently than commercially developed tests is, I think, an affront to us as physicians and molecular pathologists, to us as professionals.

In 2009 we are likely to see some assaults on the LDT - assaults on our ability to create them, on our ability to perform them, on our ability to use them for our patients.  Yet, just as the LDT has brought us into the age of molecular medicine, the LDT will be core mechanism by which medicine will proceed into the 21^st century.  We need to be very cautious that regulatory zeal or that market financial incentives do not impair the LDT, and its very important translational function for modern medicine.  We should not underestimate the LDT’s significance for the advancement of medical science.