Optimizing immunofluorescence with high-dynamic-range imaging to enhance PD-L1 expression evaluation for 3D pathology assessment from NSCLC tumor tissue.

Assessing programmed death ligand 1 (PD-L1) expression through immunohistochemistry (IHC) is the golden standard in predicting immunotherapy response of non-small cell lung cancer (NSCLC). However, observation of heterogeneous PD-L1 distribution in tumor space is a challenge using IHC only. Meanwhile, immunofluorescence (IF) could support both planar and three-dimensional (3D) histological analyses by combining tissue optical clearing with confocal microscopy. We optimized clinical tissue preparation for the IF assay focusing on staining, imaging, and post-processing to achieve quality identical to traditional IHC assay. To overcome limited dynamic range of the fluorescence microscope's detection system, we incorporated a high dynamic range (HDR) algorithm to restore the post imaging IF expression pattern and further 3D IF images. Following HDR processing, a noticeable improvement in the accuracy of diagnosis (85.7%) was achieved using IF images by pathologists. Moreover, 3D IF images revealed a 25% change in tumor proportion score for PD-L1 expression at various depths within tumors. We have established an optimal and reproducible process for PD-L1 IF images in NSCLC, yielding high quality data comparable to traditional IHC assays. The ability to discern accurate spatial PD-L1 distribution through 3D pathology analysis could provide more precise evaluation and prediction for immunotherapy targeting advanced NSCLC.

Cost-effectiveness analysis of atezolizumab plus bevacizumab compared with sorafenib as first-line treatment in advanced hepatocellular carcinoma in Singapore.

OBJECTIVES: This study aims to explore the cost-effectiveness of atezolizumab plus bevacizumab against sorafenib for first-line treatment of locally advanced or metastatic hepatocellular carcinoma (HCC) in Singapore. METHODS: A partitioned survival model was developed from a healthcare system perspective, with a 10-year lifetime horizon. Clinical inputs and utilities were obtained from the IMbrave150 trial. Healthcare resource use costs were obtained from published local sources; drug costs reflected the most recent public hospital selling prices. Outcomes included life years, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). Deterministic and probabilistic sensitivity analyses were performed to assess the model's robustness. RESULTS: Atezolizumab plus bevacizumab offered an additional 1.42 life years and 1.09 QALYs, with an additional cost of S$111,847; the ICER was S$102,988/QALY. The World Health Organization considers interventions with ICERs <1 gross domestic product (GDP)/capita to be highly cost-effective. At a willingness-to-pay (WTP) threshold of S$114,165/QALY (Singapore's 2022 GDP/capita), atezolizumab plus bevacizumab is cost-effective compared with sorafenib. The ICER was most sensitive to variations in utilities, but all parameter variations had no significant impact on the model outcomes. CONCLUSION: At a WTP threshold of Singapore's GDP/capita, atezolizumab plus bevacizumab is cost-effective compared with sorafenib.

Assessment of programmed death-ligand 1 expression in primary tumors and paired lymph node metastases of gastric adenocarcinoma.

BACKGROUND: Anti-programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) immunotherapy has demonstrated promising results on gastric cancer (GC). However, PD-L1 can express differently between metastatic sites and primary tumors (PT). AIM: To compare PD-L1 status in PT and matched lymph node metastases (LNM) of GC patients and to determine the correlation between the PD-L1 status and clinicopathological characteristics. METHODS: We retrospectively reviewed 284 GC patients who underwent D2-gastrectomy. PD-L1 was evaluated by immunohistochemistry (clone SP142) using the combined positive score. All PD-L1+ PT staged as pN+ were also tested for PD-L1 expression in their LNM. PD-L1(-) GC with pN+ served as the comparison group. RESULTS: Among 284 GC patients included, 45 had PD-L1+ PT and 24 of them had pN+. For comparison, 44 PD-L1(-) cases with pN+ were included (sample loss of 4 cases). Of the PD-L1+ PT, 54.2% (13/24 cases) were also PD-L1+ in the LNM. Regarding PD-L1(-) PT, 9.1% (4/44) had PD-L1+ in the LNM. The agreement between PT and LNM had a kappa value of 0.483. Larger tumor size and moderate/severe peritumoral inflammatory response were associated with PD-L1 positivity in both sites. There was no statistical difference in overall survival for PT and LNM according to the PD-L1 status (P = 0.166 and P = 0.837, respectively). CONCLUSION: Intra-patient heterogeneity in PD-L1 expression was observed between the PT and matched LNM. This disagreement in PD-L1 status may emphasize the importance of considering different tumor sites for analyses to select patients for immunotherapy.

Effectiveness of Nivolumab in Second-Line and Later in Patients with Advanced Non-Small Cell Lung Cancer in Real-Life Practice in France and Germany: Analysis of the ESME-AMLC and CRISP Cohorts.

This study reports characteristics and outcomes in patients with locally advanced or metastatic non-small cell lung cancer (aNSCLC) receiving nivolumab in second-line or later (2L+) in France and Germany between 2015 and 2020. Patients with aNSCLC (stage IIIB-C/IV) receiving nivolumab in 2L+ were included from the retrospective Epidemiological Strategy and Medical Economics of Advanced and Metastatic Lung Cancer cohort (ESME-AMLC, France; 2015-2019) and Clinical Research platform Into molecular testing, treatment and outcome of non-Small cell lung carcinoma Patients (CRISP, Germany; 2016-2020). Overall, 2262 ESME-AMLC and 522 CRISP patients were included. Median treatment duration (95% confidence intervals) was 2.8 months (2.5-3.2) in squamous and 2.5 months (2.3-2.8) in non-squamous/others patients in ESME-AMLC, and 2.3 months (1.4-3.1) and 2.3 months (2.0-2.8), respectively in CRISP. One-year and two-year overall survival (OS) were 47.2% and 26.7% in squamous and 50.8% and 32.8% in non-squamous/others patients in ESME-AMLC, and 43.1% and 20.9%, and 37.7% and 18.9%, respectively in CRISP. Poorer performance score and shorter time from start of previous line of therapy initiation were significantly associated with shorter treatment duration and OS. This study confirms, in real-world clinical databases, the efficacy of nivolumab previously observed in clinical trials.

Cost-effectiveness analysis of pembrolizumab vs. chemotherapy as second-line treatment for advanced esophageal carcinoma in the United States.

Background: The national Comprehensive Cancer Network has suggested pembrolizumab as a second-line therapy for esophageal squamous cell carcinoma (ESCC) patients with a programmed death ligand-1 (PD-L1) combined positive score (CPS) ≥ 10. However, despite the increased survival rate associated with pembrolizumab in these patient population, the high cost of pembrolizumab may influence its antitumor effect. This study aimed to evaluate the cost-effectiveness of pembrolizumab compared to chemotherapy as second-line treatments for esophageal carcinoma (EC) based on KEYNOTE-181 trial. Methods: A Markov model was constructed using TreeAge 2021 based on three different groups: all intent-to-treat patients (ITT population), patients with ESCC (ESCC population), and patients with a PD-L1 CPS ≥10 (CPS ≥10 population). Incremental cost, Incremental effect, Life-years, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio (ICER) were calculated. Analyses were conducted on the setting of a willingness-to-pay threshold of $150,000 from the US perspective. Results: The ICERs for pembrolizumab were $157,589.545 per QALY, $60,238.823 per QALY, and $100,114.929 per QALY compared with chemotherapy in the ITT, ESCC, and CPS≥10 populations, respectively. The ICER of the ITT population was higher than $150,000, suggesting that pembrolizumab was not a cost-effective treatment scheme in patients with a PD-L1 CPS ≤ 10 or esophageal adenocarcinoma. The ICER was < $150,000 in the ESCC and CPS≥10 populations, indicating that pembrolizumab was cost-effective in these two subgroups. Conclusion: The determining of pembrolizumab as a cost-effective second-line therapy for EC in the United States depends on the histologic type and PD-L1 expression.

Assessment of radiographic and prognostic characteristics of programmed death-ligand 1 expression in high-grade gliomas.

PURPOSE: Gliomas are characterized by immunosuppressive features. Programmed death-ligand 1 (PD-L1) is overexpressed and plays an important role in the immunosuppressive tumor microenvironments of gliomas. However, the radiographical and prognostic significance of PD-L1 expression remains unclear. METHODS: Using tissue microarrays, we evaluated PD-L1 expression and the presence of tumor-infiltrating CD4+ and CD8+T cells and CD204+macrophages using immunohistochemical analysis. Contrast enhancement area and fluid-attenuated inversion recovery (FLAIR) hyperintensity area were evaluated by two-dimensional analysis. Kaplan-Meier analysis was performed to evaluate the overall survival time in 44 patients with isocitrate dehydrogenase (IDH)-wildtype glioblastoma. RESULTS: We evaluated 71 patients with newly diagnosed high-grade gliomas who were treated between October 1998 and April 2012. PD-L1 expression was observed in 15 patients (21.1%). A significant association of PD-L1 expression with the CD4+ and CD8+ T cell densities, but not with CD204+ macrophage densities, was observed (p = 0.025, p = 0.0098, and p = 0.19, respectively). The FLAIR-to-enhancement ratio was significantly higher in PD-L1+ tumors than in PD-L1- tumors (p = 0.0037). PD-L1 expression did not show a significant association with the median survival time (PD-L1 + vs. PD-L1-: 19.2 vs 14.9 months; p = 0.39). CONCLUSION: PD-L1 expression was associated with CD4+ and CD8+ T cell infiltration, indicating a significant interplay between PD-L1 and immune cells. The positive correlation of PD-L1 expression with an increased FLAIR-to-enhancement ratio suggested that radiographical characteristics could reflect the immunological status. Our results did not support the prognostic impact of PD-L1 in patients with IDH-wildtype glioblastomas.

Application of molecular imaging in immune checkpoints therapy: From response assessment to prognosis prediction.

Recently, immune checkpoint therapy (ICT) represented by programmed cell death1 (PD-1) and its major ligands, programmed death ligand 1 (PD-L1), has achieved significant success. Detection of PD-L1 by immunohistochemistry (IHC) is a classic method to guide the treatment of ICT patients. However, PD-L1 expression in the tumor microenvironment is highly complex. Thus, PD-L1 IHC is inadequate to fully understand the relevance of PD-L1 levels in the whole body and their dynamics to improve therapeutic outcomes. Intriguingly, numerous studies have revealed that molecular imaging technologies could potentially meet this need. Therefore, the purpose of this narrative review is to summarize the preclinical and clinical application of ICT guided by molecular imaging technology, and to explore the future opportunities and practical difficulties of these innovations.

Evaluation of PD-L1 (E1L3N, 22C3) expression in venous tumor thrombus is superior to its assessment in renal tumor in predicting overall survival in renal cell carcinoma.

BACKROUND: Renal cell carcinoma (RCC) frequently invades renal vein forming neoplastic thrombus. The expression of immune checkpoint receptors in RCC was addressed in multiple studies, but little is known about the expression and prognostic significance of programmed death ligand-1 in tumor thrombus. MATERIAL AND METHODS: The study aimed to evaluate the expression of PD-L1 within venous tumor thrombus and primary tumor using 2 independent antibody clones (22c3 and E1L3N) and to assess its value in predicting overall survival (OS) in the subgroup of patients with RCC and renal vein thrombus. RESULTS: Eighty-two patients with RCC and venous tumor thrombus that underwent nephrectomy were enrolled. The expression of PD-L1 was assessed utilizing tissue microarrays separately on tumor cells (TCs) and tumor-infiltrating lymphocytes (TILs). The frequency of PD-L1 expression on TCs and TILs varied between tumor and thrombus compartments and was dependent on the antibody clone used. The expression of PD-L1 on TCs and/or TILs was associated with worse OS irrespectively of the antibody and the analyzed compartment. Nevertheless, the best prognostic performance was noted for the combined assessment of PD-L1 expression on TCs and TILs in venous tumor thrombus with the use of 22c3 antibody. The multivariable Cox regression model predicting OS incorporated PD-L1 22c3 in venous tumor thrombus (hazards ratio [HR] = 3.64, 95% confidence interval [CI] = 1.63-8.14, P = 0.002) and nodal status (HR = 2.88, 95% CI = 1.18-7.03, P = 0.02). CONCLUSIONS: PD-L1 may become a valuable tool for prognostic purposes in this specific subgroup of patients and be incorporated into the respective models qualifying for adjuvant treatment.

Cost-Effectiveness of Cemiplimab Versus Standard of Care in the United States for First-Line Treatment of Advanced Non-small Cell Lung Cancer With Programmed Death-Ligand 1 Expression ≥50.

OBJECTIVES: This study aimed to evaluate the cost-effectiveness, from a US commercial payer perspective, of cemiplimab versus other first-line treatments for advanced non-small cell lung cancer with programmed death-ligand 1 expression ≥50%. METHODS: A 30-year "partitioned survival" model was constructed. Overall survival and progression-free survival were estimated by applying time-varying hazard ratios from a network meta-analysis of randomized clinical trials. Overall survival and progression-free survival were estimated from EMPOWER-Lung 1 (cemiplimab monotherapy vs chemotherapy) and KEYNOTE-024 and KEYNOTE-042 (pembrolizumab monotherapy vs chemotherapy). Drug acquisition costs were based on published 2020 US list prices. A 3% discount rate was applied to life-years, quality-adjusted life-years (QALYs), and costs. A deterministic analysis was performed on the base case; 1-way sensitivity and probabilistic sensitivity analyses assessed model and parameter uncertainties. RESULTS: Cemiplimab was associated with increased time in the "preprogression" (13.08 vs 7.90 and 6.08 months) and "postprogression" (47.30 vs 29.49 and 14.78 months) health states versus pembrolizumab and chemotherapy, respectively. Compared with pembrolizumab and chemotherapy, cemiplimab generated 1.00 (95% CI -0.266 to 2.440) and 1.78 (95% CI 0.607-3.20) incremental QALYs, respectively, with incremental cost-effectiveness ratios of $68 254 and $89 219 per QALY for cemiplimab versus pembrolizumab and cemiplimab versus chemotherapy, respectively. The probability of cemiplimab being cost-effective at a willingness-to-pay threshold of $100 000 to $150 000 per QALY was 62% to 76% versus pembrolizumab and 56% to 84% versus chemotherapy. CONCLUSIONS: Findings suggest that cemiplimab, versus pembrolizumab or versus chemotherapy, is a cost-effective first-line treatment option for advanced non-small cell lung cancer with programmed death-ligand 1 expression ≥50%.

Development and validation of a supervised deep learning algorithm for automated whole-slide programmed death-ligand 1 tumour proportion score assessment in non-small cell lung cancer.

AIMS: Immunohistochemical programmed death-ligand 1 (PD-L1) staining to predict responsiveness to immunotherapy in patients with advanced non-small cell lung cancer (NSCLC) has several drawbacks: a robust gold standard is lacking, and there is substantial interobserver and intraobserver variance, with up to 20% discordance around cutoff points. The aim of this study was to develop a new deep learning-based PD-L1 tumour proportion score (TPS) algorithm, trained and validated on a routine diagnostic dataset of digitised PD-L1 (22C3, laboratory-developed test)-stained samples. METHODS AND RESULTS: We designed a fully supervised deep learning algorithm for whole-slide PD-L1 assessment, consisting of four sequential convolutional neural networks (CNNs), using aiforia create software. We included 199 whole slide images (WSIs) of 'routine diagnostic' histology samples from stage IV NSCLC patients, and trained the algorithm by using a training set of 60 representative cases. We validated the algorithm by comparing the algorithm TPS with the reference score in a held-out validation set. The algorithm had similar concordance with the reference score (79%) as the pathologists had with one another (75%). The intraclass coefficient was 0.96 and Cohen's κ coefficient was 0.69 for the algorithm. Around the 1% and 50% cutoff points, concordance was also similar between pathologists and the algorithm. CONCLUSIONS: We designed a new, deep learning-based PD-L1 TPS algorithm that is similarly able to assess PD-L1 expression in daily routine diagnostic cases as pathologists. Successful validation on routine diagnostic WSIs and detailed visual feedback show that this algorithm meets the requirements for functioning as a 'scoring assistant'.

Assessment of PD-L1 expression in patients with neuroblastoma and renal tumors.

BACKGROUND: Programmed death 1 (PD-1) is a co-receptor which is located at the surface of cells like natural killer, monocytes, T and B cells. It has two ligands including programmed death ligand-1 (PD-L1) and ligand-2 (PD-L2). T cell functions are inhibited by activation of PD-1/PD-L1 pathway and this pathway is used by viruses and some tumor cells in order to escape from immune eradication. In our study we evaluated PD-L1 expression in the tissue specimens of patients with Wilms tumor, neuroblastoma and other renal tumors. METHODS: Totally 60 patients who were followed up at Gazi University Hospital with the diagnosis of neuroblastoma, Wilms tumor and other renal tumors were included. PD-L1 expression was examined in tumor samples of the patients. RESULTS: Positive staining with PD-L1 was detected only in two male patients. Both of them had neuroblastoma and advanced stage disease. None of the patients with Wilms tumor and other renal tumors had positive PD-L1 staining. CONCLUSIONS: Unlike adult tumors, PD-L1 expression is not common in childhood tumors due to differences in immune system between children and adults. Further studies are needed to establish the importance and effects of PD-1/PD-L1 pathway in pediatric tumors.

Assessment of PD-L1 Expression on Circulating Tumor Cells for Predicting Clinical Outcomes in Patients with Cancer Receiving PD-1/PD-L1 Blockade Therapies.

BACKGROUND: Programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) blockade immunotherapies have changed the landscape of cancer therapy. However, the main limitation of these therapies is the lack of definitively predictive biomarkers to predict treatment response. Whether PD-L1 expression on circulating tumor cells (CTCs) is associated with the clinical outcomes of immunotherapy remains to be extensively investigated. MATERIALS AND METHODS: One hundred fifty-five patients with different advanced cancers were enrolled in this study and treated with anti-PD-1/PD-L1 monoclonal antibodies. Using the Pep@MNPs method, CTCs were isolated and enumerated. The PD-L1 expression levels were analyzed by an immunofluorescence assay for semiquantitative assessment with four categories (negative, low, medium, and high). RESULTS: Prior to immunotherapy, 81.93% (127/155) of patients had PD-L1-positive CTCs, and 71.61% (111/155) had at least one PD-L1-high CTC. The group with PD-L1-positive CTCs had a higher disease control rate (DCR) (71.56%, 91/127), with a DCR of only 39.29% (11/28) for the remaining individuals (p = .001). The objective response rate and DCR in PD-L1-high patients were higher than those in the other patients (32.44% vs. 13.64%, p = .018 and 75.68% vs. 40.91%, p < .0001, respectively). The reduction in the counts and ratios of PD-L1-positive CTCs and PD-L1-high CTCs reflected a beneficial response to PD-1/PD-L1 inhibitors. Furthermore, patients with PD-L1-high CTCs had significantly longer progression-free survival (4.9 vs. 2.2 months, p < .0001) and overall survival (16.1 vs. 9.0 months, p = .0235) than those without PD-L1-high CTCs. CONCLUSION: The PD-L1 level on CTCs may serve as a clinically actionable biomarker for immunotherapy, and its dynamic changes could predict the therapeutic response. IMPLICATIONS FOR PRACTICE: This study was designed to investigate the role of programmed death-ligand 1 (PD-L1) expression on circulating tumor cells in predicting and monitoring response to programmed death-1 (PD-1)/PD-L1 blockade immunotherapies in patients with advanced cancer. The results of the study showed that PD-L1-high-expression circulating tumor cells (CTCs) were both a predictive biomarker and a prognostic factor in patients with advanced cancer treated with anti-PD-1/PD-L1 monoclonal antibodies. These observations suggest that PD-L1 level on CTCs is a potential clinical biomarker for immunotherapy.

Longitudinal assessment of PD-L1 expression and gene expression profiles in patients with head and neck cancer reveals temporal heterogeneity.

BACKGROUND: Programmed death-ligand 1 (PD-L1) is the most validated predictive biomarker used for the treatment of head and neck squamous cell carcinoma (HNSCC) with immune checkpoint inhibitors (ICI). Several gene expression-based signatures surrogate of the activation of IFN-gamma pathway and of the presence of tertiary lymphoid structures (TLS) have also been proposed as potential biomarkers. While they may have a potential therapeutic implication, the longitudinal changes of either PD-L1 or gene expression profiles between the initial and recurrent HNSCC lesions is unknown. METHODS: PD-L1 immunohistochemistry (IHC) and targeted RNA-sequencing of 2,549 transcripts were analyzed on paired specimens from the initial diagnosis and recurrent HNSCC. PD-L1 status was defined using the combined positive score (CPS). PD-L1 mRNA levels were compared with protein expression levels by IHC. Enrichment scores of surrogate signatures for TLS and IFN-gamma (IFN-γ) pathway activation were computed using the single sample gene set enrichment analysis (ssGSEA). RESULTS: PD-L1 status was 64% (21/33) concordant between the initial and recurrent lesions using a CPS 1 threshold and 67% (22/33) concordant using a CPS 20 threshold. CPS score was associated with PD-L1 gene expression levels. There was a 43% (15/35) and 66% (23/35) concordance for the IFN-γ and TLS signature scores, respectively. CONCLUSION: Our study reveals temporal heterogeneity of PD-L1 status and TLS/IFN-γ gene expression surrogates in HNSCC that need to be considered when interpreting biomarker studies.

[A Real-world Study on the Assessment of Pathological Characteristics and Targeted Therapeutic Effect of Non-small Cell Lung Cancer Patients with Positive Driving Genes and High PD-L1 Expression].

BACKGROUND: Targeted therapy for patients with driver genes positive and immunotherapy for patients with driver gene-negative but high programmed death ligand 1 (PD-L1) expression are the standards of first-line treatment for patients with advanced non-small cell lung cancer (NSCLC). The treatment options for patients with driver gene positive and high PD-L1 expression are still worth exploring. METHODS: The characteristics of 315 patients with NSCLC were identified to analyze the clinicopathological characteristics of patients with driver gene positive and high PD-L1 expression, and the efficacy of targeted therapy. RESULTS: Among the 315 patients, the total positive rate of driver genes was 62.2%, and the high PD-L1 expression rate (≥50.0%) was 11.2%. The proportion of patients with driver gene positive and high PD-L1 expression was 10.7%. PD-L1 was highly expressed in patients with epidermal growth factor receptor (EGFR) mutation, KRAS mutation, ALK fusion, BRAF mutation, and MET 14 exon skip mutation, the proportions were 7.8% (11/141), 18.2% (4/22), and 23.1%, (3/13), 50.0% (2/4) and 100.0% (1/1) respectively. EGFR mutation positive with PD-L1 high expression was mainly in patients with stage IV lung adenocarcinoma. KRAS mutation positive with PD-L1 high expression was mainly in patients with a history of smoking. Among them, two patients were followed in detail for targeted therapy, who with ALK fusion-positive and PD-L1 high expression (90.0%), EGFR L858R mutation and PD-L1 high expression (70.0%) respectively. The total OS of the patients was 5 months, 2 months. CONCLUSIONS: The high PD-L1 expression rate in NSCLC patients with different driver gene mutations was variable, which maybe correlated with distinct clinicopathological characteristics. Patients with sensitive mutations and high PD-L1 expression may be less benefit from targeted therapy and have poor prognosis.

Feasibility study of cryobiopsy for practical pathological diagnosis of primary lung cancer including immunohistochemical assessment.

BACKGROUND: Precision medicine in non-small cell lung cancer requires attainment of a sufficient amount of high-quality tumor tissue. Transbronchial cryobiopsy has emerged as a new diagnostic method for non-neoplastic lung disease with a better potential to assess morphology compared with conventional methods. However, the influence of cryobiopsy on specimen quality, particularly detection of protein expression, is unknown. We performed a comparative immunohistochemical study in specimens obtained by cryobiopsy versus conventional sampling to evaluate the feasibility of cryobiopsy for lung cancer diagnosis. METHODS: Pairs of artificial biopsy specimens, collected using a cryoprobe or conventional scalpel, were obtained from 43 surgically resected primary lung tumors. Formalin-fixed, paraffin-embedded blocks were prepared in an ISO15189-certified laboratory. Immunohistochemical staining of thyroid transcription factor-1, p40, Ki67 and programmed death-ligand 1 (22C3) was performed. The H-scores for thyroid transcription factor-1 and p40, labeling index for Ki67 and tumor proportion score for programmed death-ligand 1 were assessed. Pearson's correlation coefficients between two sampling types were calculated. RESULTS: The thyroid transcription factor-1 and p40 H-scores showed perfect correlations between the cryobiopsy and conventional scalpel-obtained specimens (R2 = 0.977 and 0.996, respectively). Ki67 labeling index and PD-L1 tumor proportion score also showed strong correlations between the two sample types (R2 = 0.896 and 0.851, respectively). Five cases (11.6%) exhibited differences in tumor proportion score category between sample types, potentially because of intratumoral heterogeneity. CONCLUSIONS: Immunohistochemical expression of certain tumor markers showed a high concordance between cryobiopsy and conventional scalpel sampling. Cryobiopsy is feasible for pathological diagnostics including PD-L1 evaluation.

A meta-analysis of CD274 (PD-L1) assessment and prognosis in colorectal cancer and its role in predicting response to anti-PD-1 therapy.

BACKGROUND: PD-1 checkpoint inhibitors are novel therapeutic agents in colorectal cancer (CRC). Immunohistochemical staining for CD274 assessment is standardised in upper GI cancer, but not in CRC. METHODS: Methodologies of relevant studies were scrutinized and meta-analysis of survival and CD274/PDCD1 performed. Furthermore, anti-PD-1 therapy clinical trial results in CRC were assessed with particular emphasis on CD274 assessment. RESULTS: 24 studies were included. CD274 on immune cells was associated with good prognosis. CD274 on tumour cells has heterogenous outcomes and does not meet requirements of a prognostic marker. As a marker of response to anti-PD-1 therapy, CD274 assessment is not standardised in CRC. CONCLUSION: CD274 does not appear useful as a prognostic marker. As a marker of response to anti-PD-1 therapy, assessment methodology requires standardisation. As the Combined Positive Score (CPS) is used in upper GI cancer, this seems a logical method to adopt. Thresholds for CRC remain to be determined.

Cost-effectiveness analysis of atezolizumab in advanced triple-negative breast cancer.

BACKGROUND: The IMpassion130 trial demonstrated that adding atezolizumab to nanoparticle albumin-bound (nab)-paclitaxel improved the survival of patients with untreated, advanced, programmed death ligand 1 (PDL1)-positive triple-negative breast cancer (TNBC). In view of the high cost of immunotherapy, it is important to examine its value with respect to both benefits and costs. In this study, the cost-effectiveness of atezolizumab/nab-paclitaxel combination therapy relative to nab-paclitaxel monotherapy was evaluated for the first-line treatment of advanced, PDL1-positive TNBC, from a healthcare system perspective. METHODS: A three-state partitioned-survival model was developed to compare the clinical and economic outcomes of treatment with atezolizumab/nab-paclitaxel combination therapy with nab-paclitaxel monotherapy in patients with advanced TNBC. Clinical data were obtained from the IMpassion130 trial and extrapolated to 5 years. Health state utilities were retrieved from the literature, while direct costs (in Singapore dollars, S$) were sourced from public healthcare institutions in Singapore. The primary outcomes of the model were life years (LYs), quality-adjusted LYs (QALYs), costs and incremental cost-effectiveness ratios (ICERs). One-way and probabilistic sensitivity analyses and scenario analyses were conducted to explore the impact of specific assumptions and uncertainties. RESULTS: Adding atezolizumab to nab-paclitaxel resulted in an additional 0.361 QALYs (0.636 LYs) at an ICER of S$324,550 per QALY gained. The ICER remained high at S$67,092 per QALY even when atezolizumab was priced zero. One-way sensitivity analysis showed that the ICER was most sensitive to variations in the cost of atezolizumab and the time horizon. Scenario analyses confirmed that the ICERs remained high even under extremely favourable assumptions. CONCLUSIONS: Given the exceedingly high ICER, adding atezolizumab to nab-paclitaxel was unlikely to represent good value for money for the treatment of advanced PDL1-positive TNBC. Our findings will be useful in informing funding policy decisions alongside other considerations such as comparative effectiveness, unmet need and budget impact.

MicroRNAs aid the assessment of programmed death ligand 1 expression in patients with non-small cell lung cancer.

The qualification of patients with non-small cell lung cancer (NSCLC) for anti-programmed cell death 1 (PD-1) or anti-programmed death ligand 1 (PD-L1) antibody therapy is based on an immunohistochemistry (IHC) assessment of PD-L1 expression. Immunological checkpoint inhibitors improve the overall survival of patients with expression of PD-L1; however certain PD-L1-negative patients may also benefit from immunotherapy. This indicates the requirement for novel predictive factors for the qualification of immunotherapy. It is also necessary to understand the mechanisms that effect the expression of PD-L1 in tumor cells. The expression of PD-L1 in 47 formalin-fixed, paraffin-embedded, NSCLC specimens was assessed using IHC and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of 8 microRNAs (miRNAs, miRs) complementary to PD-L1-mRNA was also evaluated using RT-qPCR. A positive correlation was revealed between the expression level of PD-L1-mRNA and 2 miRs, miR-141 (R=0.533; P=0.0029) and miR-1184 (R=0.463; P=0.049). There was also a positive correlation between the percentage of PD-L1-positive tumor cells and the expression levels of miR-141 (R=0.441; P=0.0024), miR-200b (R=0.372; P=0.011) and miR-429 (R=0.430; P=0.0028), and between the percentage of the tumor area with immune cell infiltration and the expression levels of miR-141 (R=0.333; P=0.03) and miR-200b (R=0.312; P=0.046). Additionally, the percentage of tumor cells expressing PD-L1 positively correlated with miR-141 expression (R=0.407; P=0.0055). Correlations between the expression of the investigated miRs (particularly miR-141) and PD-L1 indicated that miRs may regulate PD-L1 expression at a post-transcriptional level.

Conformance Assessment of PD-L1 Expression Between Primary Tumour and Nodal Metastases in Non-Small-Cell Lung Cancer.

INTRODUCTION: Programmed death-ligand 1 (PD-L1) expression as measured by immunohistochemistry (IHC) has been employed to predict the efficacy of anti-PD-1/PD-L1 therapy. Nevertheless, heterogeneous PD-L1 expression represents a challenge for the selection of patients for anti-PD-1/PD-L1 therapy. METHODS: PD-L1 expression using clone 22C3 in 76 resected non-small-cell lung cancer and paired nodal metastases was assessed and classified according to the proportion of immunostained tumour cells using cutoff values of 1%, 5%, and 50%. RESULTS: The concordance rates for PD-L1 expression between primary and metastatic lymph nodes (N1) at these cutoff values were 67.7% (21/31) (Kappa value: 0.455, p<0.000), 60.0% (15/25) (Kappa value: 0.668, p<0.000), and 62.5% (5/8) (Kappa value: 0.497, p<0.000). In 36 paired N1 lymph nodes and N2 lymph nodes, 54.5% (6/11) (Kappa value: 0.625, p<0.000) of cases of PD-L1 expression were coincident at cutoffs of 1%. If stratified by adenocarcinoma and squamous cell carcinoma, 87.5% (14/16) (Kappa value: 0.830, p<0.000) of cases at the 1% cutoff and 46.7% (7/15) (Kappa value: 0.324, p<0.000) of cases at the 1% cutoff were coincident. CONCLUSION: The results of this study demonstrate that the concordance of PD-L1 expression between primary tumour and nodal metastases is low in non-small-cell lung cancer but is high in adenocarcinoma. Our results also suggest that PD-L1 expression in either lymph nodes or tumour tissues does not predict survival. PD-L1 detection in metastatic lymph nodes is not a suitable replacement for PD-L1 detection in the primary lesion.