Image-based multiplex immune profiling of cancer tissues: translational implications. A report of the International Immuno-oncology Biomarker Working Group on Breast Cancer.

Recent advances in the field of immuno-oncology have brought transformative changes in the management of cancer patients. The immune profile of tumours has been found to have key value in predicting disease prognosis and treatment response in various cancers. Multiplex immunohistochemistry and immunofluorescence have emerged as potent tools for the simultaneous detection of multiple protein biomarkers in a single tissue section, thereby expanding opportunities for molecular and immune profiling while preserving tissue samples. By establishing the phenotype of individual tumour cells when distributed within a mixed cell population, the identification of clinically relevant biomarkers with high-throughput multiplex immunophenotyping of tumour samples has great potential to guide appropriate treatment choices. Moreover, the emergence of novel multi-marker imaging approaches can now provide unprecedented insights into the tumour microenvironment, including the potential interplay between various cell types. However, there are significant challenges to widespread integration of these technologies in daily research and clinical practice. This review addresses the challenges and potential solutions within a structured framework of action from a regulatory and clinical trial perspective. New developments within the field of immunophenotyping using multiplexed tissue imaging platforms and associated digital pathology are also described, with a specific focus on translational implications across different subtypes of cancer. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Spatial analyses of immune cell infiltration in cancer: current methods and future directions: A report of the International Immuno-Oncology Biomarker Working Group on Breast Cancer.

Modern histologic imaging platforms coupled with machine learning methods have provided new opportunities to map the spatial distribution of immune cells in the tumor microenvironment. However, there exists no standardized method for describing or analyzing spatial immune cell data, and most reported spatial analyses are rudimentary. In this review, we provide an overview of two approaches for reporting and analyzing spatial data (raster versus vector-based). We then provide a compendium of spatial immune cell metrics that have been reported in the literature, summarizing prognostic associations in the context of a variety of cancers. We conclude by discussing two well-described clinical biomarkers, the breast cancer stromal tumor infiltrating lymphocytes score and the colon cancer Immunoscore, and describe investigative opportunities to improve clinical utility of these spatial biomarkers. © 2023 The Pathological Society of Great Britain and Ireland.

Pitfalls in machine learning-based assessment of tumor-infiltrating lymphocytes in breast cancer: A report of the International Immuno-Oncology Biomarker Working Group on Breast Cancer

The clinical significance of the tumor-immune interaction in breast cancer is now established, and tumor-infiltrating lymphocytes (TILs) have emerged as predictive and prognostic biomarkers for patients with triple-negative (estrogen receptor, progesterone receptor, and HER2-negative) breast cancer and HER2-positive breast cancer. How computational assessments of TILs might complement manual TIL assessment in trial and daily practices is currently debated. Recent efforts to use machine learning (ML) to automatically evaluate TILs have shown promising results. We review state-of-the-art approaches and identify pitfalls and challenges of automated TIL evaluation by studying the root cause of ML discordances in comparison to manual TIL quantification. We categorize our findings into four main topics: (1) technical slide issues, (2) ML and image analysis aspects, (3) data challenges, and (4) validation issues. The main reason for discordant assessments is the inclusion of false-positive areas or cells identified by performance on certain tissue patterns or design choices in the computational implementation. To aid the adoption of ML for TIL assessment, we provide an in-depth discussion of ML and image analysis, including validation issues that need to be considered before reliable computational reporting of TILs can be incorporated into the trial and routine clinical management of patients with triple-negative breast cancer. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Beneficial Effects of Mifepristone Treatment in Patients with Breast Cancer Selected by the Progesterone Receptor Isoform Ratio: Results from the MIPRA Trial.

PURPOSE: Preclinical data suggest that antiprogestins inhibit the growth of luminal breast carcinomas that express higher levels of progesterone receptor isoform A (PRA) than isoform B (PRB). Thus, we designed a presurgical window of opportunity trial to determine the therapeutic effects of mifepristone in patients with breast cancer, based on their high PRA/PRB isoform ratio (MIPRA; NCT02651844). PATIENTS AND METHODS: Twenty patients with luminal breast carcinomas with PRA/PRB > 1.5 (determined by Western blots), and PR ≥ 50%, naïve from previous treatment, were included for mifepristone treatment (200 mg/day orally; 14 days). Core needle biopsies and surgical samples were formalin fixed for IHC studies, while others were snap-frozen to perform RNA sequencing (RNA-seq), proteomics, and/or Western blot studies. Plasma mifepristone levels were determined using mass spectrometry. The primary endpoint was the comparison of Ki67 expression pretreatment and posttreatment. RESULTS: A 49.62% decrease in Ki67 staining was observed in all surgical specimens compared with baseline (P = 0.0003). Using the prespecified response parameter (30% relative reduction), we identified 14 of 20 responders. Mifepristone induced an increase in tumor-infiltrating lymphocytes; a decrease in hormone receptor and pSer118ER expression; and an increase in calregulin, p21, p15, and activated caspase 3 expression. RNA-seq and proteomic studies identified downregulated pathways related to cell proliferation and upregulated pathways related to immune bioprocesses and extracellular matrix remodeling. CONCLUSIONS: Our results support the use of mifepristone in patients with luminal breast cancer with high PRA/PRB ratios. The combined effects of mifepristone and estrogen receptor modulators warrant clinical evaluation to improve endocrine treatment responsiveness in these patients. See related commentary by Ronchi and Brisken, p. 833.

Multicenter study of diffuse pleural mesothelioma. histopathological and immunohistochemical features / Estudio multicéntrico de características histopatológicas e inmunohistoquímicas del mesotelioma pleural difuso

Abstract The pathological diagnosis of diffuse pleural mesothelioma (DPM) contributes to treatment selection and clinical trials interpretation. To know its characteristics and evaluate the viability of comprehensive pathological diagnosis of DPM in Argentina we did a retrospective descriptive study of DPM cases reported from 2009 to 2018. We analyzed 398 cases corresponding to 238 (60%) men and 160 (40%) women, median age 66 years, from surgical biopsies (78%), small biopsies (16.5%) and surgical resections (5.5%). The 77% were epithelioid (E-DPM), 12% biphasic, 10% sarcomatoid, and 4 cases transitional variant. In E-DPM the main pattern was tubular in 36% and solid in 33%. There was a second pattern in 179 cases. Considering the main pattern and the second together, 48% presented tubular subtype and 48% solid subtype. Stroma, necrosis, and nuclear score showed significant differences between E-DPM and non-epithelioid mesotheliomas. Overall tumor grade was predominantly low in E-DPM, except for 42% of the solid main pattern. We recognized the transitional variant extensively in 4 cases and focally in 8. The immunohistochemical antibody panel used included pan-cytokeratin, calretinin, WT-1, cytokeratin 5, CEA and TTF-1. The expression of cytokeratin 5, calretinin and WT-1 was lower in the sarcomatoid type (43%, 87 and 37%) than in the epithelioid type (92%, 98% and 93%). This study highlights the tumor heterogeneity of DPM that shows the diagnostic difficulty, and the feasibility of evaluating histological aggressiveness in E-DPM, B-DPM and S-DPM in our country.

Resumen El diagnóstico patológico del mesotelioma pleural difuso (MPD) contribuye a la selección del tratamiento y a la interpretación de los ensayos clínicos. Para conocer sus características y evaluar la viabilidad del diagnóstico patológico de MPD en Argentina se realizó un estudio descriptivo retros pectivo de los casos de MPD informados de 2009 a 2018. Se analizaron 398 casos correspondientes a 238 (60%) hombres y 160 (40%) mujeres, mediana de edad de 66 años, a partir de biopsias quirúrgicas (78%), biopsias pequeñas (16.5%) y resecciones quirúrgicas (5.5%). El 77% fue epitelioide (E-MPD), 12% bifásicos, 10% sarcomatoides y 4 casos variante transicional. En E-MPD se encontró como patrón principal el tubular en 36% y el sólido en 33%. Hubo un segundo patrón en 179 casos. Considerando el principal y el segundo patrón en conjunto, el 48% presentó subtipo tubular y el 48% subtipo sólido. El estroma, la necrosis y el score nuclear mostraron diferencias significativas entre E-MPD y mesoteliomas no epitelioides. El grado general del tumor fue predominantemente bajo en E-MPD, a excepción del 42% del patrón principal sólido. Reconocimos la variante transicional en forma extensa en 4 casos y focalmente en 8. La expresión de citoqueratina 5, calretinina y WT-1 fue menor en el tipo sarcomatoide (43%, 87 y 37%) que en el tipo epitelioide (92%, 98% y 93%). Este estudio destaca la heterogeneidad tumoral de MPD que evidencia la dificu ltad en el diagnóstico y la viabilidad de evaluar la agresividad histológica en E-MPD, B-MPD y S-MPD en nuestro país.

Multicenter study of diffuse pleural mesothelioma. Histopathological and immunohistochemical features.

The pathological diagnosis of diffuse pleural mesothelioma (DPM) contributes to treatment selection and clinical trials interpretation. To know its characteristics and evaluate the viability of comprehensive pathological diagnosis of DPM in Argentina we did a retrospective descriptive study of DPM cases reported from 2009 to 2018. We analyzed 398 cases corresponding to 238 (60%) men and 160 (40%) women, median age 66 years, from surgical biopsies (78%), small biopsies (16.5%) and surgical resections (5.5%). The 77% were epithelioid (E-DPM), 12% biphasic, 10% sarcomatoid, and 4 cases transitional variant. In E-DPM the main pattern was tubular in 36% and solid in 33%. There was a second pattern in 179 cases. Considering the main pattern and the second together, 48% presented tubular subtype and 48% solid subtype. Stroma, necrosis, and nuclear score showed significant differences between E-DPM and non-epithelioid mesotheliomas. Overall tumor grade was predominantly low in E-DPM, except for 42% of the solid main pattern. We recognized the transitional variant extensively in 4 cases and focally in 8. The immunohistochemical antibody panel used included pan-cytokeratin, calretinin, WT-1, cytokeratin 5, CEA and TTF-1. The expression of cytokeratin 5, calretinin and WT-1 was lower in the sarcomatoid type (43%, 87 and 37%) than in the epithelioid type (92%, 98% and 93%). This study highlights the tumor heterogeneity of DPM that shows the diagnostic difficulty, and the feasibility of evaluating histological aggressiveness in E-DPM, B-DPM and S-DPM in our country.

El diagnóstico patológico del mesotelioma pleural difuso (MPD) contribuye a la selección del tratamiento y a la interpretación de los ensayos clínicos. Para conocer sus características y evaluar la viabilidad del diagnóstico patológico de MPD en Argentina se realizó un estudio descriptivo retrospectivo de los casos de MPD informados de 2009 a 2018. Se analizaron 398 casos correspondientes a 238 (60%) hombres y 160 (40%) mujeres, mediana de edad de 66 años, a partir de biopsias quirúrgicas (78%), biopsias pequeñas (16.5%) y resecciones quirúrgicas (5.5%). El 77% fue epitelioide (E-MPD), 12% bifásicos, 10% sarcomatoides y 4 casos variante transicional. En E-MPD se encontró como patrón principal el tubular en 36% y el sólido en 33%. Hubo un segundo patrón en 179 casos. Considerando el principal y el segundo patrón en conjunto, el 48% presentó subtipo tubular y el 48% subtipo sólido. El estroma, la necrosis y el score nuclear mostraron diferencias significativas entre E-MPD y mesoteliomas no epitelioides. El grado general del tumor fue predominantemente bajo en E-MPD, a excepción del 42% del patrón principal sólido. Reconocimos la variante transicional en forma extensa en 4 casos y focalmente en 8. La expresión de citoqueratina 5, calretinina y WT-1 fue menor en el tipo sarcomatoide (43%, 87 y 37%) que en el tipo epitelioide (92%, 98% y 93%). Este estudio destaca la heterogeneidad tumoral de MPD que evidencia la dificu ltad en el diagnóstico y la viabilidad de evaluar la agresividad histológica en E-MPD, B-MPD y S-MPD en nuestro país.

The tale of TILs in breast cancer: A report from The International Immuno-Oncology Biomarker Working Group.

The advent of immune-checkpoint inhibitors (ICI) in modern oncology has significantly improved survival in several cancer settings. A subgroup of women with breast cancer (BC) has immunogenic infiltration of lymphocytes with expression of programmed death-ligand 1 (PD-L1). These patients may potentially benefit from ICI targeting the programmed death 1 (PD-1)/PD-L1 signaling axis. The use of tumor-infiltrating lymphocytes (TILs) as predictive and prognostic biomarkers has been under intense examination. Emerging data suggest that TILs are associated with response to both cytotoxic treatments and immunotherapy, particularly for patients with triple-negative BC. In this review from The International Immuno-Oncology Biomarker Working Group, we discuss (a) the biological understanding of TILs, (b) their analytical and clinical validity and efforts toward the clinical utility in BC, and (c) the current status of PD-L1 and TIL testing across different continents, including experiences from low-to-middle-income countries, incorporating also the view of a patient advocate. This information will help set the stage for future approaches to optimize the understanding and clinical utilization of TIL analysis in patients with BC.

The path to a better biomarker: application of a risk management framework for the implementation of PD-L1 and TILs as immuno-oncology biomarkers in breast cancer clinical trials and daily practice.

Immune checkpoint inhibitor therapies targeting PD-1/PD-L1 are now the standard of care in oncology across several hematologic and solid tumor types, including triple negative breast cancer (TNBC). Patients with metastatic or locally advanced TNBC with PD-L1 expression on immune cells occupying ≥1% of tumor area demonstrated survival benefit with the addition of atezolizumab to nab-paclitaxel. However, concerns regarding variability between immunohistochemical PD-L1 assay performance and inter-reader reproducibility have been raised. High tumor-infiltrating lymphocytes (TILs) have also been associated with response to PD-1/PD-L1 inhibitors in patients with breast cancer (BC). TILs can be easily assessed on hematoxylin and eosin-stained slides and have shown reliable inter-reader reproducibility. As an established prognostic factor in early stage TNBC, TILs are soon anticipated to be reported in daily practice in many pathology laboratories worldwide. Because TILs and PD-L1 are parts of an immunological spectrum in BC, we propose the systematic implementation of combined PD-L1 and TIL analyses as a more comprehensive immuno-oncological biomarker for patient selection for PD-1/PD-L1 inhibition-based therapy in patients with BC. Although practical and regulatory considerations differ by jurisdiction, the pathology community has the responsibility to patients to implement assays that lead to optimal patient selection. We propose herewith a risk-management framework that may help mitigate the risks of suboptimal patient selection for immuno-therapeutic approaches in clinical trials and daily practice based on combined TILs/PD-L1 assessment in BC. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Guía de inmunohistoquímica para técnicos / inmunohistochemist ry guide for technicians

La inmunohistoquímica (IHQ) es una técnica esencial y de uso rutinario en anatomía patológica. Contribuye en el diagnostico especifico de las enfermedades, en particular las neoplásicas; permite una adecuada clasificación en función de linaje u origen (tales como carcinoma, melanoma, linfoma, etc.); brinda información pronóstica y sus resultados, evaluados en el contexto clínico, contribuyen a la elección del tratamiento de los pacientes. Basada en la alta especificidad y afinidad de la reacción antígeno-anticuerpo la IHQ permite, mediante el empleo de anticuerpos específicos y sistemas de detección, determinar la expresión de biomarcadores (proteínas). Se puede realizar sobre tejidos en fresco, fijados en formol y coágulos citológicos incluidos en parafina, permitiendo la evaluación simultánea de la morfología. Es una técnica compleja, en la cual el resultado final está influenciado por múltiples parámetros de las fases preanalítica, analítica y post-analítica. Dependiendo de la selección y el rendimiento de estos parámetros, el resultado final de la técnica utilizando el mismo anticuerpo primario puede mostrar un rango de negativo a positivo para el antígeno objetivo. Para que su empleo sea de máxima utilidad y los resultados obtenidos sean reproducibles y confiables es imprescindible la estandarización de cada uno de los pasos o fases desde la obtención de la muestra, con la adecuada fijación de los tejidos, hasta el ajuste de la técnica, lectura y valorización de los resultados obtenidos a los criterios establecidos mediante controles de calidad internos y externos.