Preservation of fine-needle aspiration specimens for future use in RNA-based molecular testing

The Driver Role of Pathologists in Endocrine Oncology: What Clinicians Seek in Pathology Reports

Endocrine neoplasia represents an increasingly broad spectrum of disorders. Endocrine neoplasms range from incidental findings to potentially lethal malignancies. In this paper, we cover the impact of pathology in the interpretation of the clinic-pathological, genetic, and radiographic features underpinning these neoplasms. We highlight the critical role of multidisciplinary interactions in structuring a rational diagnostic and efficient therapeutic plan and emphasize the role of histopathological input in decision-making. In this context, standardized pathology reporting and second opinion endocrine pathology review represent relevant tools to improve the overall diagnostic workup of patients affected by endocrine tumors in every specific scenario. In fact, although a relevant proportion of cases may be correctly identified based on clinical presentation and biochemical/imaging investigations, a subset of cases presents with atypical findings that may lead to an inappropriate diagnosis and treatment plan based on a wrong pathological diagnosis if all pieces of the puzzle are not correctly considered. Pathologists have a responsibility to actively guide clinicians before and during surgical procedures to prevent unnecessary interventions. In all areas of endocrine pathology, pathologists must understand the complexity of tissue preservation and assay sensitivities and specificities to ensure the optimal quality and interpretation of diagnostic material. Finally, pathologists are central actors in tumor tissue biobanking, which is an expanding field in oncology that should be promoted while adhering to strict ethical and methodological standards.

Thyroglobulin as a negative marker for malignancy in canine and human breast tumors

Canine mammary gland tumors (CMTs) are the most common tumor type in female dogs. This study evaluated the expression pattern and role of thyroglobulin (Tg) in CMT and in human breast cancer (HBC). CMT samples were subjected to fine-needle aspiration, primary cell culture, and histopathology. The expression level of Tg was higher in benign CMT than in malignant CMT (mCMT) primary cells, particularly in the epithelial lineage. Moreover, treatment with Tg enhanced the sensitivity of doxorubicin in mCMT epithelial cells and mitigated proinflammatory response by increasing nuclear factor erythroid 2-related factor 2 (Nrf2). The proximal region of the Tg promoter was hypermethylated in mCMT epithelial cells, silencing Tg expression with concurrent downregulation of Nrf2-mediated antioxidant signaling. An identical pattern of Tg expression was observed in cytological and tissue samples. Tissue microarray analysis showed that Tg was highly expressed in normal and benign tissues when compared with their malignant counterparts, which was diminished along with higher histological grades. The survival rate was significantly higher in HBC patients with high Tg expression than those with low Tg expression. This study also showed that the progression of HBC is accompanied by the reduction of Tg expression along with augmentation of proinflammatory signaling. Our data suggested that Tg could be a negative indicator of malignancy in canine and human breast neoplasia.

Actionable driver DNA variants and fusion genes can be detected in archived cytological specimens with the Oncomine Dx Target Test Multi-CDx system in lung cancer

BACKGROUND

Molecular testing is critical for identifying actionable variants in lung cancer for precision medicine. When tumor tissue samples are unavailable, archived cytological specimens (ACSs) can be used. The authors examined whether oncogenic variants could be accurately detected in ACSs versus paired formalin-fixed, paraffin-embedded (FFPE) tumor tissues with in vitro diagnostic tests.

METHODS

The authors collected 18 ACSs and 15 FFPE tissues from 15 patients with lung cancer and investigated genomic profiles with the Oncomine Dx Target Test Multi-CDx system, which is an integrated next-generation sequencing platform that comprehensively examines 4 companion diagnostic target genes (epidermal growth factor receptor [EGFR]; B-Raf proto-oncogene, serine/threonine kinase [BRAF]; anaplastic lymphoma kinase [ALK]; and ROS proto-oncogene 1, receptor tyrosine kinase [ROS1]). They compared the quantity and quality of extracted nucleic acids, the sequencing quality control (QC), and the detected variants between ACSs and FFPE tissues.

RESULTS

The total amount of DNA and RNA obtained from 1 slide was higher in FFPE tissues than ACSs. The RNA integrity number was higher in ACSs. There were no differences in sequencing QC between ACSs and FFPE tissues. A total of 21 variants, including EGFR mutations and ALK and ROS1 fusion genes, were detected in both ACSs and FFPE tissues with 100% concordance.

CONCLUSIONS

ACSs can be a feasible alternative with which to identify actionable mutations and fusion genes via the Oncomine Dx Target Test Multi-CDx system.

Small but powerful: the promising role of small specimens for biomarker testing

Emphasis on the use of small specimens for biomarker testing to provide prognostic and predictive information for guiding clinical management for patients with advanced-stage cancer has been increasing. These biomarker tests include molecular analysis, cytogenetic tests, and immunohistochemical assays. Owing to the limited nature of the cellular material procured in these small specimens, which are collected using minimally invasive techniques (ie, fine needle aspiration and core needle biopsy), pathologists have been required to triage these samples judiciously and provide the clinically relevant genomic information required for patient care. Awareness of the advantages and limitations of these specimen preparations and the specific preanalytic requirements for the testing methods will help pathologists to develop optimal strategies to maximize the chances of effectively using these samples for comprehensive diagnostic and relevant biomarker testing.

Rapid Nanophotonics Assay for Head and Neck Cancer Diagnosis

Efficient and timely diagnosis of head and neck squamous cell carcinoma (HNSCC) is a critical challenge, particularly in low and middle income countries. These regions, which are expected to witness a drastic increase in HNSCC rates, are ill-prepared to handle the diagnostic burden due to limited resources, especially the low ratio of pathologists per population, resulting in delayed diagnosis and treatment. Here, we demonstrate the potential of an alternative diagnostic method as a low-cost, resource-efficient alternative to histopathological analysis. Our novel technology employs unique surface-enhanced Raman scattering (SERS) "nanorattles" targeting cytokeratin nucleic acid biomarkers specific for HNSCC. In this first study using SERS diagnostics for head and neck cancers, we tested the diagnostic accuracy of our assay using patient tissue samples. In a blinded trial, our technique demonstrated a sensitivity of 100% and specificity of 89%, supporting its use as a useful alternative to histopathological diagnosis. The implications of our method are vast and significant in the setting of global health. Our method can provide a rapid diagnosis, allowing for earlier treatment before the onset of distant metastases. In comparison to histopathology, which can take several months in remote limited-resources regions, our method provides a diagnosis within a few hours.

Preanalytic specimen triage: Smears, cell blocks, cytospin preparations, transport media, and cytobanking

With increasing requests for the evaluation of prognostic and predictive molecular biomarkers, great attention must be paid to the preanalytical issues regarding sample quality and DNA/RNA yield from all different types of cytological preparations. The objectives of this review were: 1) to provide an update regarding the importance of specimen triage as well as specimen handling and collection; 2) to discuss the different cell preparations that can be used for molecular testing, their advantages and limitations; and 3) to highlight the strategies for biobanking cytology samples. Good-quality DNA/RNA can be harvested from fresh cells in cell suspensions, formalin-fixed paraffin-embedded cell blocks, archival stained smears, archival unstained cytospin preparations, liquid-based cytology slides, FTA cards, and cryopreserved cells. In contrast to formalin-fixed paraffin-embedded tissue specimens (small biopsies and surgical resections), the multitude of types of sample preparations as well as the diversity in sample collection and processing procedures make cytology an ideal specimen for most genomic platforms, with less DNA and RNA degradation and a purer sample, usually with a higher concentration of tumor cells. The broad incorporation of cytological specimens into clinical practice. A should increase the number of samples potentially available for molecular tests and avoid repeat invasive procedures for tissue procurement, thereby increasing patient safety. In this context, it is of utmost importance that cytopathologists become familiar with the variables that can affect test results and embrace the goal of excellence in sample quality. Cancer Cytopathol 2017;125(6 suppl):455-64. © 2017 American Cancer Society.

Cryopreservation-Altered Expression of RNA and Protein Markers in Biological Specimens

The preservation of DNA, RNA, and protein markers in biological specimens is essential for initial diagnosis, subsequent verification, and comparison, as well as for archival retention of pathological materials in modern molecular diagnostics and precision medicine. Considerable attention has been paid to the methods of collection, handling, and preparation of specimens for initial testing, but insufficient attention to the long-term specimen preservation for later verification, comparison, and archival retention. In the present study, we have investigated the changes of expressions of RNAs and proteins in Hep-G2 cell specimens after cryopreservation at -80°C and in liquid nitrogen. Storage temperature and different cryoprotective agent (CPA) solutions not only affect cell viability but also more importantly the retention of various molecular markers after storage as detected by western blot and real-time fluorescent quantitative polymerase chain reaction. While the presence of CPAs increased the survival rates of cells after cryopreservation as expected, there was no consistent trend observed with regard to the RNA expression measurements. The data have significant implications with regard to the accuracy and interpretation of acquired data from specimens that have been cryopreserved without RNA and protein stabilization and point to the need for rethinking the assumptions, strategies, and criteria of optimizing biological specimen cryopreservation in molecular diagnostics.

Evaluation of RNA and DNA extraction from liquid-based cytology specimens

Molecular diagnosis using DNA and RNA derived from malignant tumors and molecular biological tools such as the quantitative polymerase-chain-reaction (qPCR) is a commonly used technique in clinical pathology. In this report, we compared the qualitative extraction of RNA and DNA from cancer cells fixed using several liquid-based cytology (LBC) kits. Ten to 1,000 cells from the T24 urinary bladder cancer cell line and SKG-II cervical cancer cell line were fixed with 55% methanol and three different methanol-based LBC solutions. The mRNA levels of CD44 in T24 cells and E7 in SKG-II cells and DNA levels of p53 in T24 cells and E7 in SKG-II cells were analyzed by qPCR. mRNA and DNA extracted from T24 and/or SKG-II cells fixed with methanol-based LBC solutions were efficiently detected, but to differing degrees, by qPCR. mRNA, and DNA from cells fixed with a formaldehyde-containing fixative liquid were detected at significantly low copy numbers by qPCR. Our results demonstrate that LBC systems are powerful tools for cytopathology and immunocytochemistry applications. However, the appropriate fixative must be selected for cell preservation when a small number of LBC samples is used for molecular testing, particularly in RNA-based molecular analyses. Diagn. Cytopathol. 2016;44:833-840. © 2016 Wiley Periodicals, Inc.

Biospecimen repositories and cytopathology

Biospecimen repositories are important for the advancement of biomedical research. Literature on the potential for biobanking of fine-needle aspiration, gynecologic, and nongynecologic cytology specimens is very limited. The potential for biobanking of these specimens as valuable additional resources to surgically excised tissues appears to be excellent. The cervicovaginal specimens that can be used for biobanking include Papanicolaou-stained monolayer preparations and residual material from liquid-based cytology preparations. Different types of specimen preparations of fine-needle aspiration and nongynecologic specimens, including Papanicolaou-stained and Diff-Quik-stained smears, cell blocks. and dedicated passes/residual material from fine-needle aspiration stored frozen in a variety of solutions, can be used for biobanking. Because of several gaps in knowledge regarding the standard of operative procedures for the procurement, storage, and quality assessment of cytology specimens, further studies as well as national conferences and workshops are needed not only to create awareness but also to facilitate the use of cytopathology specimens for biobanking.

Endoscopic ultrasound guided fine needle aspiration and useful ancillary methods

The role of endoscopic ultrasound (EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within the mediastinum and abdominal cavity allow detection of small focal lesions and precise tissue acquisition from suspected lesions within the reach of this method. Fine needle aspiration (FNA) is considered of additional value to EUS and is performed to obtain tissue diagnosis. Tissue acquisition from suspected lesions for cytological or histological analysis allows, not only the differentiation between malignant and non-malignant lesions, but, in most cases, also the accurate distinction between the various types of malignant lesions. It is well documented that the best results are achieved only if an adequate sample is obtained for further analysis, if the material is processed in an appropriate way, and if adequate ancillary methods are performed. This is a multi-step process and could be quite a challenge in some cases. In this article, we discuss the technical aspects of tissue acquisition by EUS-guided-FNA (EUS-FNA), as well as the role of an on-site cytopathologist, various means of specimen processing, and the selection of the appropriate ancillary method for providing an accurate tissue diagnosis and maximizing the yield of this method. The main goal of this review is to alert endosonographers, not only to the different possibilities of tissue acquisition, namely EUS-FNA, but also to bring to their attention the importance of proper sample processing in the evaluation of various lesions in the gastrointestinal tract and other accessible organs. All aspects of tissue acquisition (needles, suction, use of stylet, complications, etc.) have been well discussed lately. Adequate tissue samples enable comprehensive diagnoses, which answer the main clinical questions, thus enabling targeted therapy.

Is liquid-based cytology the magic bullet for performing molecular techniques?

OBJECTIVE

The role of pathology has evolved from the first microscopic definitions of diseases by Virchow to the new concept of molecular cytopathology. The management of diseases is now a multidisciplinary approach with the translation of morphological, imagery and molecular findings to therapeutic protocols. Obtaining the most reliable diagnostic material is the essential part of the medical management of patients.

STUDY DESIGN

Here, we try to gain a concise insight into the available data regarding the role of cytology in the application of molecular techniques, focusing on cancer cytopathology.

RESULTS

Obtaining cytological material is now feasible by different methods, and in some cases it is the only possible approach to a lesion which is not easily accessible for tissue sampling. The methods of obtaining cytological material have evolved in recent years in parallel with rapid advances in high-throughput molecular techniques, opening new windows for the diagnosis and management of diseases.

CONCLUSIONS

Different kinds of cytological material are reliable for the application of molecular techniques. Cytological material obtained in a liquid base has advantages such as the better preservation of cytomorphological features and the use of the remaining liquid for nucleic acid extraction even after long storage and the application of molecular methods.

Fine-needle aspiration cytology can play a role in neoadjuvant chemotherapy in operable breast cancer

Despite the fact that CNB has been progressively replaced by FNAC in the investigation of nonpalpable lesions or microcalcifications without a clinical or radiological mass lesion, FNAC has yet a role in palpable lesions provided it is associated with the triple diagnosis and experienced cytologist. In these conditions, FNAC is a safe, effective, economical, and accurate technique for breast cancer evaluation. Numerous literature reviews and meta-analyses illustrated the advantages and disadvantages of both methods CNB and FNAC. The difference does not seem significant when noninformative and unsatisfactory FNAC was excluded. Recently, cytological methods using liquid-based cytology (LBC) technology improve immunocytological and molecular tests with the same efficiency as classical immunohistochemistry. The indications of FNAC were, for palpable lesions, relative contraindication of CNB (elderly or frailty), staging of multiple nodules in conjunction or not with CNB, staging of lymph node status, newly appearing lesion in patient under neoadjuvant treatment, decreasing of anxiety with a rapid diagnosis, evaluation of biomarkers and new biomarkers, and chronological evaluation of biomarker following the neoadjuvant therapy response.

Five Top Stories in Cytopathology

Context.—Cytology relies heavily on morphology to make diagnoses, and morphologic criteria have not changed much in recent years. The field is being shaped predominantly by new techniques for imaging and for acquiring and processing samples, advances in molecular diagnosis and therapeutics, and regulatory issues.

Objective.—To review the importance of classical morphology in the future of cytopathology, to identify areas in which cytology is expanding or contracting in its scope, and to identify factors that are shaping the field.

Data Sources.—Literature review.

Conclusions.—Five stories paint a picture in which classical cytomorphology will continue to have essential importance, both for diagnosis and for improving our understanding of cancer biology. New endoscopy and imaging techniques are replacing surgical biopsies with cytology samples. New molecularly targeted therapies offer a chance for cytology to play a major role, but they pose new challenges. New molecular tests have the potential to synergize with, but not replace, morphologic interpretation of thyroid fine-needle aspirations. Ultrasound-guided fine-needle aspiration performed by cytopathologists is opening a new field of “interventional cytopathology” with unique value. For the productive evolution of the field, it will be important for cytopathologists to play an active role in clinical trials that document the ability of cytology to achieve cost-effective health care outcomes.

Targeting tyrosine kinases in cancer: the converging roles of cytopathology and molecular pathology in the era of genomic medicine

Because of knowledge gained in the field of cancer biology, clinicians are currently witnessing an explosion of molecular tests as companion diagnostics to targeted therapies against growth factor receptors and their signaling pathways. Such tests are being applied increasingly to cytology specimens as essential components of genomic medicine, because less invasive diagnostic procedures are becoming the norm. The objective of this review was to present an overview of the current and future role of cytopathology in molecular diagnostics, including the adequacy of cytology specimens for such studies. The authors also discuss the critical methodologic aspects of the molecular assays used for the selection of tyrosine kinase treatment for oncology patients.

Ancillary techniques on direct-smear aspirate slides: a significant evolution for cytopathology techniques

Numerous cytologic techniques aimed at effectively acquiring patient material for molecular testing have been proposed. Such techniques are becoming ever more important in an age of personalized medicine. In this commentary, the authors explored some more commonly proposed techniques to aid in the molecular testing of cytologic specimens. These techniques include the use of cell blocks, direct cytologic smears, filter paper storage, frozen samples, and enriched cellular techniques such as ThinPrep and cytospin preparations. Direct-smeared slides demonstrate excellent preservation of DNA, are easy to prepare, and are amenable to immediate adequacy at the time of the fine-needle aspiration (FNA) procedure as well as effective subsequent tumor purity estimation. Cell block methods cannot be assessed at the time of FNA and often demonstrate insufficiency, whereas filter paper and frozen techniques do not allow for the direct assessment of the presence and purity of tumor cells in the sample. Direct-smeared slides are emerging as the most effective preparation and storage medium of cytologic material to be used for molecular testing. Their cost-effectiveness, ease of use, and reliability have cemented them as the optimal solution for cytopathologists to fulfill the role of providing advanced molecular testing on patient samples.

High-throughput molecular analysis from leftover of fine needle aspiration cytology of mammographically detected breast cancer

We investigated whether residual material from diagnostic smears of fine needle aspirations (FNAs) of mammographically detected breast lesions can be successfully used to extract RNA for reliable gene expression analysis. Twenty-eight patients underwent FNA of breast lesions under ultrasonographic guidance. After smearing slides for cytology, residual cells were rinsed with TRIzol to recover RNA. RNA yield ranged from 0.78 to 88.40 µg per sample. FNA leftovers from 23 nonpalpable breast cancers were selected for gene expression profiling using oligonucleotide microarrays. Clusters generated by global expression profiles partitioned samples in well-distinguished subgroups that overlapped with clusters obtained using "biologic scores" (cytohistologic variables) and differed from clusters based on "technical scores" (RNA/complementary RNA/microarray quality). Microarray profiling used to measure the grade of differentiation and estrogen receptor and ERBB2/HER2 status reflected the results obtained by histology and immunohistochemistry. Given that proliferative status in the FNA material is not always assessable, we designed and performed on FNA leftover a multiprobe genomic signature for proliferation genes that strongly correlated with the Ki67 index examined on histologic material. These findings show that cells residual to cytologic smears of FNA are suitable for obtaining high-quality RNA for high-throughput analysis even when taken from small nonpalpable breast lesions.

The Establishment of the First Cancer Tissue Biobank at a Hispanic-Serving Institution: A National Cancer Institute-Funded Initiative between Moffitt Cancer Center in Florida and the Ponce School of Medicine and Health Sciences in Puerto Rico

Population-based studies are important to address emerging issues in health disparities among populations. The Partnership between the Moffitt Cancer Center (MCC) in Florida and the Ponce School of Medicine and Health Sciences (PSMHS) in Puerto Rico (the PSMHS-MCC Partnership) was developed to facilitate high-quality research, training, and community outreach focusing on the Puerto Rican population in the island and in the mainland, with funding from the National Cancer Institute. We report here the establishment of a Tissue Biobank at PSMHS, modeled after the MCC tissue biorepository, to support translational research projects on this minority population. This facility, the Puerto Rico Tissue Biobank, was jointly developed by a team of basic and clinical scientists from both institutions in close collaboration with the administrators and clinical faculty of the tissue accrual sites. The efforts required and challenges that needed to be overcome to establish the first functional, centralized cancer-related biobank in Puerto Rico, and to ensure that it continuously evolves to address new needs of this underserved Hispanic population, are described. As a result of the collaborative efforts between PSMHS and MCC, a tissue procurement algorithm was successfully established to acquire, process, store, and conduct pathological analyses of cancer-related biospecimens and their associated clinical-pathological data from Puerto Rican patients with cancer recruited at a tertiary hospital setting. All protocols in place are in accordance with standard operational procedures that ensure high quality of biological materials and patient confidentiality. The processes described here provide a model that can be applied to achieve the establishment of a functional biobank in similar settings.

Maximizing the yield of lymph node cytology: Lessons learned from rapid onsite evaluation of image- and endoscopic-guided biopsies of hilar and mediastinal lymph nodes

The evaluation of mediastinal and hilar lymph nodes for tissue diagnosis and staging of lung cancer is now commonly performed by minimally invasive, nonsurgical procedures such as computed tomography-guided fine-needle aspiration and endobronchial ultrasound-guided transbronchial needle aspiration. Ensuring that a sufficient quantity of cellular material has been acquired to enable multiple studies has become a priority issue in the era of personalized medicine, especially for patients with lung cancer, and this can be accomplished by rapid onsite evaluation (ROSE). This commentary focuses on the use of ROSE in guided procedures, especially for hilar and mediastinal lymph node aspirates, and describes an algorithm for handling these specimens.