Comprehensive Genomic Studies on the Cell Blocks of Pancreatic Cancer.

Pancreatic cancer is one of the deadliest malignancies, characterized by late-stage diagnosis and limited treatment options. Comprehensive genomic profiling plays an important role in understanding the molecular mechanisms underlying the disease and identifying potential therapeutic targets. Cell blocks (CBs), derived from EUS-FNA, have become valuable resources for diagnosis and genomic analysis. We examine the molecular profile of pancreatic ductal adenocarcinoma (PDAC) using specimens obtained from CB EUS-FNA, across a large gene panel, within the framework of next-generation sequencing (NGS). Our findings revealed that over half (55%) of PDAC CB cases provided adequate nucleic acid for next-generation sequencing, with tumor cell percentages averaging above 30%. Despite challenges such as low DNA quantification and degraded DNA, sequencing reads showed satisfactory quality control statistics, demonstrating the detection of genomic alterations. Most cases (84.6%) harbored at least one gene variant, including clinically significant gene mutation variants such as KRAS, TP53, and CDKN2A. Even at minimal concentrations, as long as the extracted DNA is of high quality, performing comprehensive molecular profiling on PDAC samples from cell blocks has remained feasible. This strategy has yielded valuable information about the diagnosis, genetic landscape, and potential therapeutic targets, aligning closely with a precision cytopathology approach.

Expression Profile of Microenvironmental Factors in the Interface Zone of Colorectal Cancer: Histological-Stromal Biomarkers and Cancer Cell-Cancer-Associated Fibroblast-Related Proteins Combined for the Assessment of Tumor Progression.

INTRODUCTION: The characterization of tumor microenvironment (TME) related factors and their impact on tumor progression have attracted much interest. We investigated cancer cells and cancer-associated fibroblasts (CAFs) to evaluate biomarkers that are associated with neoplastic progression, observing them in different interface zones of colorectal cancer. METHODS: On 357 CRC tissue microarrays, using immunohistochemistry, we examined the associations of podoplanin and α-SMA expressed in cancer cells and CAFs and evaluated them in different areas: tumor core, invasive front, tumor budding, tumor-stroma ratio (TSR) scoring, and desmoplastic stroma. RESULTS: CAFs expressing α-SMA were found in more than 90% of the cases. Podoplanin+ was detected in cancer cells and CAFs, with positivities of 38.6% and 70%, respectively. Higher α-SMA+ CAFs and podoplanin+ cancer cells were observed predominantly at the TSR score area: 94.3% and 64.3% of cases, respectively. The status of podoplanin in CAFs+ was higher in the desmoplastic area (71.6%). Stroma-high tumors showed increased expression of α-SMA and podoplanin in comparison with stroma-low tumors. The status of podoplanin in cancer cells was observed in association with lymphatic invasion and distant metastasis. CONCLUSION: The substance of the CRC was composed predominantly of the surrounding stroma-α-SMA+ CAFs. Podoplanin expressed in the prognosticator zones was associated with unfavorable pathological features. The combination of histologic and protein-related biomarkers can result in a tool for the stratification of patients with CRC.

Challenging the concept of "risk of malignancy" in cytology.

Several standardized systems for nongynecological cytopathology have been published following the successful implementation of The Bethesda System for Reporting Cervical Cytology. Each of these systems comprises a set of reporting categories accompanied by a risk of malignancy. However, in most cases, these risk of malignancy estimates have not been based on high-quality evidence and often may not be consider proper "risks" (because they have been estimated based on cross-sectional studies). This commentary discusses the problems related to the data used to generate these risks. To make nongynecological cytopathology reporting more evidence-based, large-scale prospective cohort studies and randomized trials, in addition to high-quality systematic reviews and meta-analyses, should be performed.

Tissue management in precision medicine: What the pathologist needs to know in the molecular era.

Precision medicine is "an emerging approach for disease treatment and prevention that takes into account individual variability in genes, environment, and lifestyle for each person." Among many medical specialists involved in precision medicine, the pathologists play an important and key role in the implementation and development of molecular tests that are in the center of decision of many therapeutic choices. Besides many laboratory procedures directly involved in the molecular tests, is fundamental to guarantee that tissues and cells collected for analysis be managed correctly before the DNA/RNA extraction. In this paper we explore the pivotal and interconnected points that can influence molecular studies, such as pre-analytical issues (fixation and decalcification); diagnosis and material selection, including the calculation of nuclei neoplastic fraction. The standardization of sample processing and morphological control ensures the accuracy of the diagnosis. Tissue or cytological samples constitutes the main foundation for the determination of biomarkers and development of druggable targets. Pathology and precision oncology still have a long way to go in terms of research and clinical practice: improving the accuracy and dissemination of molecular tests, learning in molecular tumor boards for advanced disease, and knowledge about early disease. Precision medicine needs pathology to be precise.

Standardized Assessment of the Tumor-Stroma Ratio in Colorectal Cancer: Interobserver Validation and Reproducibility of a Potential Prognostic Factor.

The tumor stroma plays a relevant role in the initiation and evolution of solid tumors. Tumor-stroma ratio (TSR) is a histological feature that expresses the proportion of the stromal component that surrounds cancer cells. In different studies, the TSR represents a potential prognostic factor: a rich stroma in tumor tissue can promote invasion and aggressiveness. The aim of this study was to evaluate the reproducibility and determine the interobserver agreement in the TSR score. The stromal estimate was evaluated in patients diagnosed with colorectal adenocarcinoma (CRA), who underwent surgical resection. We also evaluated age, gender, and other anatomopathological features. Tumor-stroma ratio was calculated based on the slide used in routine diagnostic pathology to determine the T-status. Stromal percentages were separated into 2 categories: ⩽50%-low stroma and >50%-high stroma. The interobserver agreement in the TSR scoring was evaluated among 4 pathologists at different stages of professional experience, using 2 different ways to learn the scoring system. In total, 98 patients were included in this study; 54.1% were male, with a mean age of 61.9 years. Localized disease was diagnosed in 60.2% of patients. Stromal-poor CRA was predominant. The concordance between the TSR percentages of the 4 pathologists was substantial (Kappa > 0.6). There was greater agreement among pathologists for stromal-poor tumors. Substantial agreement and high reproducibility were observed in the determination of TSR score. The TSR score is feasible, suggesting that the presented methodology can be used to facilitate the determination of the stromal proportion of potential prognostic factor.