PD-L1 Immunohistochemistry in Gastric Cancer: Comparison of Combined Positive Score and Tumor Area Positivity Across 28-8, 22C3, and SP263 Assays.

PURPOSE: The clinical application of PD-L1 immunohistochemistry (IHC) testing is complicated by the availability of multiple IHC assays, scoring algorithms, and cutoffs. This study assessed the analytical comparability of three commercially available PD-L1 assays and two scoring algorithms used to assess PD-L1 status in gastric cancer (GC) samples. METHODS: Serial sections of 100 resected GC samples, with PD-L1 expression levels across the dynamic range, were stained with three in vitro diagnostic-grade PD-L1 assays (28-8, 22C3, and SP263). Three trained pathologists blindly and independently scored slides using combined positive score (CPS) and tumor area positivity (TAP) algorithms. Comprehensive statistical analyses were performed to evaluate analytical concordance. Digital image analysis (DIA) was used to objectively compare the technical performance of each assay by simulating CPS and TAP. RESULTS: Comparable staining patterns were observed with these three PD-L1 assays. Despite discernible variation in staining intensity, reproducible evaluations of PD-L1 positivity were observed. Inter- and intra-assay assessments of all three assays, using either CPS or TAP and the same PD-L1 cutoffs, demonstrated moderate to almost-perfect (interassay Cohen's kappa [κ] range, 0.47-0.83) and substantial to almost-perfect (intra-assay κ range, 0.77-1.00) agreement. Interpathologist assessment exhibited a significant level of concordance (intraclass correlation coefficient ≥0.92). No difference in technical performance was observed using DIA. CONCLUSION: This study highlights analytical concordance in PD-L1 testing between three major PD-L1 assays when TAP and CPS are applied. Comparability of the technical assay performance was further supported by independent DIA. These observations support cross-application flexibility of the different PD-L1 assays and scoring algorithms to characterize PD-L1 expression in GC.

Cost-effectiveness analysis comparing companion diagnostic tests for EGFR, ALK, and ROS1 versus next-generation sequencing (NGS) in advanced adenocarcinoma lung cancer patients.

BACKGROUND: The treatment of choice for advanced non-small cell lung cancer is selected according to the presence of specific alterations. Patients should undergo molecular testing for relevant modifications and the mutational status of EGFR and translocation of ALK and ROS1 are commonly tested to offer the best intervention. In addition, the tests costs should also be taken in consideration. Therefore, this work was performed in order to evaluate the cost-effectiveness of a unique exam using NGS (next generation sequencing) versus other routinely used tests which involve RT-PCR and FISH. METHODS: The target population was NSCLC, adenocarcinoma, and candidates to first-line therapy. Two strategies were undertaken, strategy 1 corresponded to sequential tests with EGFR RT-PCR, then FISH for ALK and ROS1. Strategy 2 differed from 1 in that ALK and ROS1 translocation testing were performed simultaneously by FISH. Strategy 3 considered single test next-generation sequencing, a platform that includes EGFR, ALK and ROS1 genes. A decision tree analysis was used to model genetic testing options. From the test results, a microsimulation model was nested to estimate survival outcomes and costs of therapeutic options. RESULTS: The use of NGS added 24% extra true cases as well as extra costs attributed to the molecular testing. The ICER comparing NGS with sequential tests was US$ 3479.11/correct case detected. The NGS improved a slight gain in life years and QALYs. CONCLUSION: Our results indicated that, although precise, the molecular diagnosis by NGS of patients with advanced stage NSCLC adenocarcinoma histology was not cost-effective in terms of quality-adjusted life years from the perspective of the Brazilian supplementary health system.

Cost effectiveness analysis of plasma genotyping versus tumor genotyping in detection of advanced non-small-cell lung cancer with epidermal growth factor receptor and T790M mutation under the Brazilian private healthcare system perspective / Custo-efetividade do uso da biópsia líquida versus biópsia tecidual para detecção de câncer de pulmão de não pequenas células avançado com receptor do fator de crescimento epidérmico e mutação T790M sob a perspectiva do sistema suplementar de saúde do Brasil

Objective: Comparing the costs and effectiveness of plasma genotyping versus tumor genotyping for detecting the T790M mutation in advanced non-small cell lung cancer (NSCLC) with a mutation in the epidermal growth factor receptor (EGFR) and that progressed after use of an EGFR tyrosine kinase inhibitor (EGFR-TKI), from the perspective of the private healthcare system in Brazil. Methods: Patients with a post-EGFR-TKI T790M mutation are eligible for a second-line treatment with a third-generation EGFR-TKI (osimertinib). In order to estimate the costs associated with the diagnosis method for the T790M mutation, a decision tree model has been used. Resource use was estimated by a team of experts, and the direct costs were estimated based on official databases. Results: Plasma genotyping provided a R$391 reduction per patient, due to the reduced cost with complications; it prevented 40.96% of the patients from undergoing an invasive procedure and 31.91% of the patients from having any kind of complication. Conclusion: Data found support a new paradigm for treating the resistance to EGFR-TKIs, with plasma genotyping as the first diagnostic choice, what can help to define the treatment and to reduce the costs of Brazilian private healthcare system.

Objetivo: Comparar os custos e efetividade da biópsia líquida versus biópsia tecidual para detecção da mutação T790M no câncer de pulmão de não pequenas células (CPNPC) avançado com mutação no receptor do fator de crescimento epidérmico (EGFR) e que progrediram após o uso de um inibidor do sítio da tirosina cinase associada ao EGFR (EGFR-TKI), sob a perspectiva do sistema suplementar de saúde do Brasil. Métodos: Pacientes com mutação EGFR-T790M pós-EGFR-TKI são elegíveis ao tratamento de segunda linha com um EGFR-TKI de terceira geração (osimertinibe). Para a estimativa dos custos relacionados ao método de diagnóstico de mutação T790M, foi elaborado um modelo de árvore de decisão. A utilização de recursos foi estimada por painel de especialistas e os custos diretos foram estimados utilizando-se bases de dados oficiais. Resultados: A biópsia líquida proporcionou redução de R$ 391 por paciente, devido a uma redução no custo com complicações; evitou que 40,96% dos pacientes passassem por um procedimento invasivo e que 31,95% dos pacientes tivessem algum tipo de complicação. Conclusão: Os dados observados embasam um novo paradigma para o manejo da resistência aos EGFR-TKIs, com genotipagem pelo plasma como primeira opção diagnóstica, o que pode auxiliar na melhor definição do tratamento e reduzir custos ao sistema de saúde suplementar brasileiro.