Techniques for maximizing the performance of molecular pathology testing: responsibilities of all pathologists

Abstract

Molecular pathological analysis has an expanding role in patient diagnosis and management. The performance of these techniques relies on excellent laboratory procedures. However, the crucial step is obtaining the best samples for molecular analysis. Archiving and selection of these are the responsibilities of all pathologists even if they are not working at a center with molecular pathological facilities.This review focuses on the features of different types of materials for molecular pathological analysis. Many steps that might affect the results, including communication between the pathologist and the oncology team, features of different types of materials (cytological, tissue blocks, biopsy, circulating tumor cells (CTCs) and cell-free circulating nucleic acids), effects of tissue processing, methods for selecting the best material, and tissue saving and tumor enrichment methods are discussed. The procedures for referral to a center for molecular pathological analysis are also mentioned.Awareness of the importance of the cytopathological and histopathological material of the patients for future molecular pathological analysis by pathologists is of the utmost importance.Key Words: Molecular Pathology, Tissue saving, Tumor enrichment, Tumor percentage INTRODUCTION "Molecular Pathology" is one of the pathological methods with expanding role in patient diagnosis, prediction of prognosis and treatment. Tissue and cellular material from patients have always been valued in pathology laboratories; however they gain additional importance in the molecular pathology era with the increase in new disease classifications according to molecular changes and new targeted therapy options being determined with predictive molecular testing.While the value of diseased and normal tissue is expanding with the advances in immunohistochemistry and molecular pathology, minimally invasive techniques have taken the place of radical processes in tissue sampling along with developments in the technology. These techniques are better for the comfort of the patient but they also have disadvantages, as they provide smaller amounts of tissue for diagnosis. The management of tissues obtained with these techniques can be problematic for pathologists. The application of individualized treatment regimens developed in recent years has depended on molecular studies. The adequacy of the obtained material and its reliability for molecular investigation are of utmost importance in many cases.The diagnosis of lung carcinomas is usually made with small biopsies or cytological materials and these materials are generally the only options for further studies. Transthoracic, transbronchial fine needle aspirations, forceps biopsies, bronchial brushes, and washes are some of these materials (1). A molecular examination requires the best process and good sample quality. The most important factor for the success of molecular tests is the number of tumor cells and the percentage of mutant cells (2). The requirements for tumor cell number and mutation perc...

How to set up a molecular pathology lab: a guide for pathologists

“…The molecular pathology era has begun with the integration of molecular tests into pathology practice, especially in diagnosis of solid tumors and hematological malignancies, as a part of the improvements in molecular sciences that had been led by the completion of the Human Genome Project in early 2000s. Pathologists now have a critical role of morphomolecular assessment in this new generation medicine era ( 2 ) and therefore have critical impact on the preanalytical phase of molecular testing ( 3 ). Given that pathologists combine molecular tests with conventional pathological evaluation methods, pathology laboratories should be designed and operated in accordance with the requirements of molecular testing procedures.…”