Molecular Pathology in Contemporary Diagnostic Pathology Laboratory: An Opinion for the Active Role of Surgical Pathologists
Over the last century and a half, surgical pathology has assimilated new science and technology and in doing so, has redefined itself and what it offers to its clinical clients. After the development of histochemistry, this has more recently included refinements in tumor classification on the basis of application and insights provided by ultrastructural analysis, followed by phenotypic analysis on the basis of application and additional insights provided by immunohistochemistry (IHC). Today, after years in the research laboratory, molecular pathology techniques such as fluorescence in situ hybridization, polymerase chain reaction, reverse transcription-polymerase chain reaction, and others have become sufficiently reproducible and economical to go beyond the provision of insights into the molecular pathogenesis of diseases and actually to enter the arena of daily clinical practice. Molecular pathology is now poised to insinuate itself ubiquitously into surgical pathology through its application in the 3 basic activities of anatomic pathology: establishing the diagnosis, providing prognostic information, and, most importantly for our clinicians, offering predictive information about therapeutic modalities.
Debate in the past few years has been centered on the question of whether molecular pathology will replace morphologic evaluation. This is the same question that was raised about ultrastructure and IHC and, as with these earlier revolutionary advances, this scenario is unlikely. We can not envisage the day when the evaluation of clinical history, careful gross evaluation, and judicious sampling of resected specimens, followed by routine microscopic evaluation enriched by years of experiences, will not be crucial to efficient diagnosis and good clinical care. However, as with previous technical developments, it is nearly equally certain that to maintain its central role in the evaluation of patients, surgical pathology will need completely to incorporate the molecular diagnostic armamentarium for the understanding and characterization of diseases. If surgical pathologists attempt, even passively, to resist this change, it could have 2 hugely significant consequences: first, inviting others to perform molecular testing of surgical pathology samples, moving the central role of tissue-based diagnosis out of the field of pathology and second, compromising the strategic position of our discipline at the crossroads between the clinical practice of medicine and the scientific understanding of disease. To these 2 main arguments, we may also wish to add a financial one: molecular diagnostics is the fastest growing area of medicine, moving a budget of many billions of dollars, and a share of it should justifiably find it way to divisions of anatomic pathology, where it has the potential best to be understood and most appropriately integrated.