The optimal threshold of PD-L1 combined positive score to predict the benefit of PD-1 antibody plus chemotherapy for patients with HER2-negative gastric adenocarcinoma: a meta-analysis.

BACKGROUND: Immune checkpoint inhibitors (ICIs) combined with chemotherapy have become the first-line treatment of metastatic gastric and gastroesophageal adenocarcinomas (GEACs). This study aims to figure out the optimal combined positive score (CPS) cutoff value. METHODS: We searched for randomized phase III trials to investigate the efficacy of ICIs plus chemotherapy for metastatic GEACs compared with chemotherapy alone. Pooled analyses of hazard ratios (HRs) based on PD-L1 expression were performed. RESULTS: A total of six trials (KEYNOTE-062, KEYNOTE-590, KEYNOTE-859, ATTRACTION-04, CheckMate 649, and ORIENT-16) were included, comprising 5,242 patients. ICIs plus chemotherapy significantly improved OS (HR: 0.79, 95% CI 0.72-0.86 in global patients; HR: 0.75, 95% CI 0.57-0.98 in Asian patients) and PFS (HR: 0.74, 95% CI 0.68-0.82 in global patients; HR: 0.64, 95% CI 0.56-0.73 in Asian patients) compared with chemotherapy alone. The differences in OS (ratio of HR: 1.05, 95% CI 0.79-1.40; predictive value: - 5.1%) and PFS (ratio of HR: 1.16, 95% CI 0.98-1.36; predictive value: - 13.5%) were not statistically significant between the global and Asian patients. Subgroup analyses indicated that the optimal CPS threshold was at ≥ 5 for OS and ≥ 10 for PFS with the highest predictive values. CONCLUSIONS: The benefit derived from ICIs plus chemotherapy is similar between Asian and global GEAC patients. However, those with a PD-L1 CPS < 5 or CPS < 10 may not have significant benefits from ICIs therapy. Therefore, it is advisable to routinely assess PD-L1 expression in GEAC patients considered for ICIs treatment.

An artificial intelligence-powered PD-L1 combined positive score (CPS) analyser in urothelial carcinoma alleviating interobserver and intersite variability.

AIMS: Immune checkpoint inhibitors targeting programmed death-ligand 1 (PD-L1) have shown promising clinical outcomes in urothelial carcinoma (UC). The combined positive score (CPS) quantifies PD-L1 22C3 expression in UC, but it can vary between pathologists due to the consideration of both immune and tumour cell positivity. METHODS AND RESULTS: An artificial intelligence (AI)-powered PD-L1 CPS analyser was developed using 1,275,907 cells and 6175.42 mm2 of tissue annotated by pathologists, extracted from 400 PD-L1 22C3-stained whole slide images of UC. We validated the AI model on 543 UC PD-L1 22C3 cases collected from three institutions. There were 446 cases (82.1%) where the CPS results (CPS ≥10 or <10) were in complete agreement between three pathologists, and 486 cases (89.5%) where the AI-powered CPS results matched the consensus of two or more pathologists. In the pathologist's assessment of the CPS, statistically significant differences were noted depending on the source hospital (P = 0.003). Three pathologists reevaluated discrepancy cases with AI-powered CPS results. After using the AI as a guide and revising, the complete agreement increased to 93.9%. The AI model contributed to improving the concordance between pathologists across various factors including hospital, specimen type, pathologic T stage, histologic subtypes, and dominant PD-L1-positive cell type. In the revised results, the evaluation discordance among slides from different hospitals was mitigated. CONCLUSION: This study suggests that AI models can help pathologists to reduce discrepancies between pathologists in quantifying immunohistochemistry including PD-L1 22C3 CPS, especially when evaluating data from different institutions, such as in a telepathology setting.

Artificial intelligence enhances whole-slide interpretation of PD-L1 CPS in triple-negative breast cancer: A multi-institutional ring study.

BACKGROUND AND AIMS: Evaluation of the programmed cell death ligand-1 (PD-L1) combined positive score (CPS) is vital to predict the efficacy of the immunotherapy in triple-negative breast cancer (TNBC), but pathologists show substantial variability in the consistency and accuracy of the interpretation. It is of great importance to establish an objective and effective method which is highly repeatable. METHODS: We proposed a model in a deep learning-based framework, which at the patch level incorporated cell analysis and tissue region analysis, followed by the whole-slide level fusion of patch results. Three rounds of ring studies (RSs) were conducted. Twenty-one pathologists of different levels from four institutions evaluated the PD-L1 CPS in TNBC specimens as continuous scores by visual assessment and our artificial intelligence (AI)-assisted method. RESULTS: In the visual assessment, the interpretation results of PD-L1 (Dako 22C3) CPS by different levels of pathologists have significant differences and showed weak consistency. Using AI-assisted interpretation, there were no significant differences between all pathologists (P = 0.43), and the intraclass correlation coefficient (ICC) value was increased from 0.618 [95% confidence interval (CI) = 0.524-0.719] to 0.931 (95% CI = 0.902-0.955). The accuracy of interpretation result is further improved to 0.919 (95% CI = 0.886-0.947). Acceptance of AI results by junior pathologists was the highest among all levels, and 80% of the AI results were accepted overall. CONCLUSION: With the help of the AI-assisted diagnostic method, different levels of pathologists achieved excellent consistency and repeatability in the interpretation of PD-L1 (Dako 22C3) CPS. Our AI-assisted diagnostic approach was proved to strengthen the consistency and repeatability in clinical practice.

Discordant PD-L1 results between 28-8 and 22C3 assays are associated with outcomes of gastric cancer patients treated with nivolumab plus chemotherapy.

BACKGROUND: We evaluated the concordance/discordance of PD-L1 staining results between the 28-8 and 22C3 assays and its impact on the efficacy outcomes of advanced gastric cancer patients treated with nivolumab plus chemotherapy. METHODS: This retrospective study involved 143 gastric cancer patients treated with first-line nivolumab plus chemotherapy whose PD-L1 results with both 28-8 and 22C3 assays were available. The concordance/discordance between these assays and the inter-observer variability were evaluated for PD-L1 combined positive score (CPS) positivity. Discordant PD-L1 results were analyzed regarding survival outcomes. RESULTS: The agreement rates and Cohen's kappa values between the 28-8 and 22C3 assays were 78.3% and 0.56 (for CPS ≥ 1), 81.8% and 0.60 (for CPS ≥ 5), and 88.8% and 0.66 (for CPS ≥ 10), respectively. Inter-observer variability, as represented by the intra-class correlation coefficient, was 0.89 and 0.88 for the 28-8 and 22C3 assays, respectively. With PD-L1 CPS ≥ 5 defined as positive, 35 (24.5%) and 82 (57.3%) had concordantly positive and negative results, respectively, between the 28-8 and 22C3 assays, whereas 26 (18.2%) had discordant results. Progression-free survival was shorter for those who exhibited negatively concordant PD-L1 results and discordant PD-L1 positivity between the 28-8 and 22C3 assays relative to those with positively concordant PD-L1 results (P = 0.013). CONCLUSION: PD-L1 assays by 28-8 and 22C3 showed suboptimal concordance, while inter-observer variability was not critical in advanced gastric cancer. Discordant PD-L1 results between 28-8 and 22C3 assays may be associated with unfavorable efficacy outcomes in patients treated with nivolumab plus chemotherapy.

Factors associated with the efficacy of first-line nivolumab plus chemotherapy in advanced gastric cancer patients with deficient mismatch repair.

BACKGROUND: We aimed to investigate clinicopathologic factors leading to different clinical outcomes in patients with deficient mismatch repair protein (d-MMR) gastric cancer (GC) treated with nivolumab plus chemotherapy (nivolumab chemotherapy). METHODS: This retrospective study included 28 patients with d-MMR advanced GC treated with first-line nivolumab chemotherapy. As a control group, 68 treated with first-line chemotherapy alone were included. Clinicopathological factors, including the neutrophil-to-lymphocyte ratio (NLR) and PD-L1 combined positive score (CPS), were analyzed with regards to the efficacy outcomes. RESULTS: Progression-free survival (PFS) was longer (median PFS; not reached [NR] vs. 5.2 months, hazard ratio [HR] 0.28, P < 0.001), and overall survival (OS) tended to be longer (median OS; NR vs. 17.9 months, HR 0.43, P = 0.057) in patients treated with nivolumab chemotherapy than those treated with chemotherapy. The PFS benefit of nivolumab chemotherapy over chemotherapy was pronounced in the subgroup with a lower NLR (< 3.80 [median NLR]) (HR 0.10), whereas it was less prominent in patients with a high NLR (≥ 3.80) (HR 0.58). Among patients treated with nivolumab chemotherapy, PFS was worse in patients with a higher NLR (≥ 3.80) than in those with a lower NLR (< 3.80), and survival outcomes were similar between those with PD-L1 CPS ≥ 5 and < 5. CONCLUSION: Nivolumab chemotherapy was associated with better efficacy outcomes than chemotherapy alone among patients with d-MMR GC, but survival outcomes were poor even with nivolumab chemotherapy for those with a high NLR. Survival outcomes were not different according to PD-L1 CPS among d-MMR patients treated with nivolumab chemotherapy.

Survival impact of sequential chemotherapy following pembrolizumab for recurrent or metastatic head and neck squamous cell carcinoma.

BACKGROUND: Pembrolizumab alone or combined with chemotherapy is the standard of care for first-line treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) with positive programmed death-ligand 1 combined positive scores. However, data on second-line chemotherapy following pembrolizumab are scarce. METHODS: A single-center, retrospective study was conducted to determine the efficacies of pembrolizumab and pembrolizumab plus chemotherapy as first-line treatments and the efficacy of second-line chemotherapy for patients with R/M HNSCC who were refractory or intolerant to first-line treatment. RESULTS: Fifty-four patients were treated with pembrolizumab, and 29 received second-line therapy, with 27 opting for cetuximab-containing regimens. The median progression-free survival (PFS), overall survival (OS), and PFS on next-line therapy for first-line treatment were 4.7 (95% confidence interval [CI], 2.1-8.7), 22.1 (95% CI, 12.6-not reached), and 15.6 months (95% CI, 9.7-not reached) in the pembrolizumab group and 5.4 (95% CI, 3.3-6.8), 15.8 (95% CI, 8.6-not reached), and 13.7 months (95% CI, 8.1-not reached) in the pembrolizumab plus chemotherapy group, respectively. The overall response rate and median PFS for second-line treatment were 48.3% (95% CI, 30.4-67.0) and 6.1 months (95% CI, 2.30-8.84). The median OS for patients who received second-line treatment was 18.4 months, which was superior to the median OS of 6.0 months for patients who received the best supportive care (log-rank p = 0.10). CONCLUSION: This study indicates that cetuximab-containing second-line chemotherapy can improve outcomes in R/M HNSCC, even after first-line therapy failure or intolerance.

High Interobserver Variability Among Pathologists Using Combined Positive Score to Evaluate PD-L1 Expression in Gastric, Gastroesophageal Junction, and Esophageal Adenocarcinoma.

Reliable, reproducible methods to interpret programmed death ligand-1 (PD-L1) expression on tumor cells (TC) and immune cells (IC) are needed for pathologists to inform decisions associated with checkpoint inhibitor therapies. Our international study compared interpathologist agreement of PD-L1 expression using the combined positive score (CPS) under standardized conditions on samples from patients with gastric/gastroesophageal junction/esophageal adenocarcinoma. Tissue sections from 100 adenocarcinoma pretreatment biopsies were stained in a single laboratory using the PD-L1 immunohistochemistry 28-8 and 22C3 (Agilent) pharmDx immunohistochemical assays. PD-L1 CPS was evaluated by 12 pathologists on scanned whole slide images of these biopsies before and after a 2-hour CPS training session by Agilent. Additionally, pathologists determined PD-L1-positive TC, IC, and total viable TC on a single tissue fragment from 35 of 100 biopsy samples. Scoring agreement among pathologists was assessed using the intraclass correlation coefficient (ICC). Interobserver variability for CPS for 100 biopsies was high, with only fair agreement among pathologists both pre- (range, 0.45-0.55) and posttraining (range, 0.56-0.57) for both assays. For the 35 single biopsy samples, poor/fair agreement was also observed for the total number of viable TC (ICC, 0.09), number of PD-L1-positive IC (ICC, 0.19), number of PD-L1-positive TC (ICC, 0.54), and calculated CPS (ICC, 0.14), whereas calculated TC score (positive TC/total TC) showed excellent agreement (ICC, 0.82). Retrospective histologic review of samples with the poorest interpathologist agreement revealed the following as possible confounding factors: (1) ambiguous identification of positively staining stromal cells, (2) faint or variable intensity of staining, (3) difficulty in distinguishing membranous from cytoplasmic tumor staining, and (4) cautery and crush artifacts. These results emphasize the need for objective techniques to standardize the interpretation of PD-L1 expression when using the CPS methodology on gastric/gastroesophageal junction cancer biopsies to accurately identify patients most likely to benefit from immune checkpoint inhibitor therapy.

PD-L1 and HLA-class I expression status and their therapeutic implication in oesophageal small-cell carcinoma.

AIMS: Oesophageal small-cell carcinoma is a rare and highly aggressive subtype of oesophageal cancer with a dismal prognosis. To explore the potential applicability of immunotherapy, we investigated the expression status of programmed death ligand 1 (PD-L1) and human leukocyte antigen (HLA)-class I and the degree of tumour-infiltrating lymphocytes (TILs) in oesophageal small-cell carcinoma. METHODS AND RESULTS: PD-L1 and HLA-class I expression levels were evaluated in 10 pure small-cell carcinomas and five mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs). The combined positive score (CPS) and tumour proportion score (TPS) were used for PD-L1 assessment. Immunohistochemistry for mismatch repair (MMR) proteins was also performed. PD-L1 immunohistochemistry demonstrated CPS ≥1 in nine (60%), CPS ≥10 in five (33%), and TPS ≥1 in five (33%) cases. Overall survival was significantly longer in patients with CPS ≥1 than in those with CPS <1. HLA-class I deficiency (>50% tumour cells) was noted in five cases (33%), with no significant correlation with PD-L1 expression status. Among the five MiNENs, HLA-class I expression was decreased in the small-cell carcinoma component of three cases. HLA-class I deficiency was significantly associated with higher TNM stage and reduced TIL levels. MMR deficiency was not observed in any case. CONCLUSION: Given that a significant subset (40%) exhibited PD-L1 CPS ≥1 with preserved HLA-class I expression and high levels of TIL, the PD-1/PD-L1 pathway is a potential therapeutic target for oesophageal small-cell carcinoma.

Efficacy of PD-1 Inhibitors in First-Line Treatment for Advanced Gastroesophageal Junction and Gastric Cancer by Subgroups: A Systematic Review and Meta-Analysis.

BACKGROUND: PD-1 inhibitors have been approved for the first-line treatment of patients with advanced gastric cancer, gastroesophageal junction cancer, or esophageal adenocarcinoma. However, the results of several clinical trials are not entirely consistent, and the dominant population of first-line immunotherapy for advanced gastric/gastroesophageal junction cancer still needs to be precisely determined. OBJECTIVE: This objective of this study is to evaluate the efficacy of anti-PD-1/PD-L1 therapy in advanced gastric/gastroesophageal junction adenocarcinoma patients through a systematic review and meta-analysis of relevant clinical trials. METHOD: The PubMed, Embase, and Cochrane Library electronic databases were searched up to August 1, 2022, for clinical trials of anti-PD-1/PD-L1 immunotherapy for the first-line treatment of advanced gastroesophageal cancer. Hazard ratios and 95% confidence intervals for overall survival, progression-free survival, and objective response rates were extracted and pooled for meta-analysis. Prespecified subgroups included the following: agent type, PD-L1 expression, and high microsatellite instability. RESULTS: This study analyzed 5 RCTs involving 3,355 patients. Compared with the chemotherapy group, the combined immunotherapy group had a significantly higher objective response rate (OR = 0.63, 95% CI: 0.55-0.72, p < 0.00001) and prolonged overall survival (HR = 0.82, 95% CI: 0.76-0.88, p < 0.00001) and progression-free survival (HR = 0.75, 95% CI: 0.69-0.82, p < 0.00001). The combination of immunotherapy and chemotherapy prolonged OS in both MSI-H (HR = 0.38, p = 0.002) and MSS (HR = 0.78, p < 0.00001) populations, but there was a significant difference between groups (p = 0.02). However, in improving ORR, the benefit of ICI combined with chemotherapy in the MSS group and MSI-H group was not significantly different between groups (p = 0.52). Combination therapy with ICIs was more effective than chemotherapy alone in prolonging OS in the subgroup with a high CPS, regardless of the CPS cutoff for PD-L1. However, when the cutoff of CPS was 1, the difference between subgroups did not reach statistical significance (p = 0.12), while the benefit ratio of the MSI-H group was higher when the cutoff was 10 (p = 0.004) than when the cutoff value was 5 (p = 0.002). CONCLUSIONS: For first-line treatment of advanced gastroesophageal cancer, an ICI combination strategy is more effective than chemotherapy. The subgroup of patients with a CPS ≥10 has a more significant benefit, and CPS ≥10 has the potential to be used as an accurate marker of the dominant population of immuno-combined therapy.

Clinicopathological and prognostic significance of PD-L1 expression in colon adenocarcinoma tumor budding.

OBJECTIVE: In this study, we investigated the relationship between programmed cell death ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) expression in colon adenocarcinoma tumor budding. METHODS: This study included 122 patients with colon adenocarcinomas. The largest sample of formaldehyde-fixed paraffin-embedded tumor tissues was selected for analysis. Expression of membranous PD-L1 (clone 22C3) and the Combined Positive Score (CPS) in tumor tissues was calculated and graded according to the percentages of peritumoral and intratumoral tumor cells (0 %, 1 %, 1-5 %, >5 %). The effects of these factors on the prognosis were analyzed. RESULTS: Tumor budding was associated with adverse clinicopathological features and poor overall survival. PD-L1 (CPS%) peritumoral tumor budding (1 %/<1 %) was statistically significant in the univariate model (p = 0.004). Age, organ metastases (liver, lung, liver, lung, and peritoneum), and metastases were statistically significant in the multivariate model (p = 0.001, p = 0.004, p = 0.001, p = 0.002, p = 0.004, and p = 0.032, respectively). PD-L1 positive staining was mostly observed around the tumor and during tumor budding. PD-L1 peritumoral tumor budding rates and patients' survival rates differed significantly (log-rank = 12.07, p = 0.007). CONCLUSION: We found that patients with PD-L1 (CPS%) > 1 % in tumor budding had a shortened life expectancy and demonstrated the importance of including tumor budding areas in the samples used for biomarker evaluation. We previously reported that PD-L1 expression in tumor budding is associated with more aggressive cancer biology and poor survival, although overall survival is of limited statistical significance.

The impact of combined PD-L1 positive score on clinical response to nivolumab in patients with advanced esophageal squamous cell carcinoma.

BACKGROUND: Nivolumab is recommended for patients with advanced esophageal squamous cell carcinoma (aESCC) refractory or intolerant to fluoropyrimidine- and platinum-based chemotherapy regardless of the tumor proportion score (TPS). However, the role of combined positive score (CPS) in predicting nivolumab efficacy remains unclear. We aimed to study whether TPS or CPS is a more suitable biomarker for predicting nivolumab efficacy in these patients. METHODS: We retrospectively collected data from patients with aESCC treated with fluoropyrimidines and platinum and subsequently received nivolumab monotherapy between January 1, 2014 and September 15, 2020. Next, we evaluated the efficiencies of TPS and CPS in predicting the clinical response to nivolumab using PD-L1 IHC 22C3 pharmDx assay. RESULTS: This study included 50 patients (CPS groups: ≥ 10/1-10/ < 1, n = 24/18/8, respectively; TPS groups, ≥ 10%/1%-10%/ < 1%, n = 17/8/25, respectively). The median progression-free survival was 3.2, 2.5, and 1.5 months in the ≥ 10, 1-10 [hazard ratio (HR) vs. CPS of ≥ 10 group, 1.01; p = 0.98; adjusted HR, 1.33; p = 0.56], and < 1 CPS groups (HR vs. CPS of ≥ 10 group, 3.44; p = 0.006; adjusted HR, 1.67; p = 0.41), respectively. For the patients with CPS of ≥ 10/1-10/ < 1 and TPS of ≥ 10%/1%-10%/ < 1%, the objective response rate was 30%/25%/0% and 36%/0%/19% and the disease control rate was 60%/50%/12% (p = 0.06) and 65%/40%/38% (p = 0.30), respectively. CONCLUSIONS: This study suggests that a CPS of < 1 is not a strong predictor of efficacy but can predict the absence of response to nivolumab in patients with aESCC.

Implication of changes in PD-L1 expression during neoadjuvant chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (DCF) regimen in esophageal squamous cell carcinoma.

BACKGROUND: Neoadjuvant docetaxel plus cisplatin and 5-FU (NAC-DCF) and adjuvant nivolumab monotherapy are the standard care for locally advanced resectable esophageal squamous cell carcinoma (ESCC). However, no effective biomarkers have been found in perioperative setting. We investigated how programmed death-ligand 1 (PD-L1) changes before and after NAC-DCF and how it relates to the therapeutic effect of NAC-DCF in resectable ESCC. METHODS: PD-L1 expression in paired diagnostic biopsy and surgically resected tissues from ESCC patients who underwent surgical resection after receiving two or three NAC-DCF cycles was evaluated. PD-L1 positivity was defined as a combined positive score (CPS) of 10% ≤ . Gene expression analysis was conducted using samples before NAC-DCF. RESULTS: Sixty-six paired samples from 33 patients were included in PD-L1 expression analysis, and 33 Pre-NAC samples acquired by diagnostic biopsy were included in gene expression analysis. Pretreatment, 3 (9%), 13 (39%), and 17 (52%) patients harbored tumors with CPS ranges of < 1%, 1%-10%, and 10% ≤ , respectively. After NAC-DCF, 5 (15%), 15 (45%), and 13 (39%) tumors presented CPS ranges of < 1%, 1%-10%, and 10% ≤ , respectively. The concordance rate between Pre-and Post-NAC-DCF samples was 45%. Patients with PD-L1-negative tumors both before and after NAC-DCF (n = 9) had shorter survival and different gene expression profile characterized by upregulation in WNT signaling or neutrophils. CONCLUSIONS: A substantial PD-L1 expression alteration was observed, resulting in low concordance rate before and after NAC-DCF. Tumors persistently lacking PD-L1 had distinct gene expression profile with worse clinical outcomes, raising the need for further investigation.

Pembrolizumab for the treatment of advanced esophageal cancer.

The prognosis of patients with advanced esophageal cancer (EC) remains poor and there are limited effective therapeutic agents for EC. Pembrolizumab monotherapy exerts clinically meaningful benefits for advanced esophageal squamous cell carcinoma patients with a combined positive score of ≥10. Additionally, pembrolizumab plus doublet chemotherapy results in a significant survival benefit for patients with advanced EC as first-line treatment compared with chemotherapy alone. We provide an overview of immune checkpoint inhibitors and present important clinical data related to treatment for EC patients. In our opinion, pembrolizumab plus chemotherapy should be the standard first-line treatment for patients with advanced EC, regardless of histology and combined positive score. Biomarker studies to identify patient populations in which immune checkpoint inhibitors are expected to show efficacy are needed.

First-line pembrolizumab ± chemotherapy for recurrent/metastatic head and neck cancer: Japanese subgroup of KEYNOTE-048.

BACKGROUND: Here, we report the results of the Japanese subgroup of the phase 3 KEYNOTE-048 study of pembrolizumab alone, pembrolizumab plus platinum and 5-fluorouracil (pembrolizumab-chemotherapy), or cetuximab plus platinum and 5-fluorouracil (EXTREME) in previously untreated recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). METHODS: Primary end points were overall survival (OS) and progression-free survival (PFS). Efficacy was evaluated in patients with PD-L1 combined positive score (CPS) ≥ 20 and ≥ 1 and the total Japanese subgroup (n = 67). RESULTS: At data cutoff (25 February 2019), pembrolizumab led to longer OS versus EXTREME in the PD-L1 CPS ≥ 20 subgroup (median, 28.2 vs. 13.3 months; HR, 0.29 [95% CI 0.09-0.89]) and to similar OS in the total Japanese (23.4 vs. 13.6 months; HR, 0.51 [95% CI 0.25-1.05]) and CPS ≥ 1 subgroups (22.6 vs. 15.8 months; HR, 0.66 [95% CI 0.31-1.41]). Pembrolizumab-chemotherapy led to similar OS versus EXTREME in the PD-L1 CPS ≥ 20 (median, 18.1 vs. 15.8 months; HR, 0.72 [95% CI 0.23-2.19]), CPS ≥ 1 (12.6 vs. 15.8 months; HR, 1.19 [95% CI 0.55-2.58]), and total Japanese subgroups (12.6 vs. 13.3 months; unadjusted HR, 1.10 [95% CI 0.55-2.22]). Median PFS was similar for pembrolizumab and pembrolizumab-chemotherapy versus EXTREME in all subgroups. Grades 3-5 treatment-related adverse events occurred in 5 (22%), 19 (76%), and 17 (89%) patients receiving pembrolizumab, pembrolizumab-chemotherapy, and EXTREME, respectively. One patient receiving pembrolizumab-chemotherapy died because of treatment-related pneumonitis. CONCLUSION: These results support the use of first-line pembrolizumab and pembrolizumab-chemotherapy for Japanese patients with R/M HNSCC. Clinical trial registry ClinicalTrials.gov, NCT02358031.

PD-L1 Expression in High-Risk Early-Stage Colorectal Cancer-Its Clinical and Biological Significance in Immune Microenvironment.

Programmed death-ligand 1 (PD-L1) is an immune checkpoint molecule that can regulate immune responses in the tumor microenvironment (TME); however, the clinical applications of PD-L1 in early-stage colorectal cancer (CRC) remain unclear. In this study, we aimed to investigate the relationship between PD-L1 expression and survival outcome and explore its relevant immune responses in CRC. PD-L1 expression was evaluated by immunohistochemical staining to determine the tumor proportion score and combined positive score (CPS) in a Taiwanese CRC cohort. The oncomine immune response research assay was conducted for immune gene expression analyses. CRC datasets from the TCGA database were reappraised for PD-L1-associated gene enrichment analyses using GSEA. The high expression of PD-L1 (CPS ≥ 5) was associated with longer recurrence-free survival (p = 0.031) and was an independent prognostic factor as revealed by multivariate analysis. High PD-L1 expression was related to six immune-related gene signatures, and CXCL9 is the most significant overexpressed gene in differential analyses. High CXCL9 expression correlated with increased infiltration levels of immune cells in the TME, including CD8+ T lymphocytes and M1 macrophages. These findings suggest that high PD-L1 expression is a prognostic factor of early-stage CRC, and CXCL9 may play a key role in regulating PD-L1 expression.

Combined Positive Score for Programmed Death Ligand-1 Expression and Inflammatory Microenvironment in Gastrointestinal Stromal Tumors.

Background and Objectives: GISTs are the most frequent type of mesenchymal neoplasm of the digestive tract. The prognosis is mainly determined by tumor dimensions, mitotic rate and location, but other less well-documented factors can influence evolution and survival. The immune microenvironment and checkpoint molecule expression were proven to impact the prognosis in different types of cancer. The aim of this study was to determine PD-L1 expression in GISTs and to evaluate the level of intratumoral immune infiltration in relation to prognostic variables and survival. Materials and Methods: Sixty-five GISTs diagnosed in the same institution between 2015 and 2018 were immunohistochemically tested for PD-L1 and evaluated using CPS. Immune cells were emphasized, with CD3, CD4, CD8, CD20 and CD68 antibodies and quantified. All data were processed using statistical tools. Results: The median age was 61 years (range, 28-78) and 36 patients (55.4%) were males. The location of the tumors was predominantly gastric (46%), followed by the small bowel (17%) and colorectal (6%). In addition, 11% were EGISTs and 20% were secondary tumors (11% metastases and 9% local recurrences). PD-L1 had a variable expression in tumor and inflammatory cells, with a CPS ranging from 0 to 100. Moreover, 64.6% of cases were PD-L1 positive with no significant differences among categories of variables, such as the age and the sex of the patient, tumor location, the primary or secondary character of the tumor, dimensions, mitotic rate, the risk of disease progression and tumor cell type. Immune cells had a variable distribution throughout the tumors. CD3+ lymphocytes were the most frequent type. CD20+ cells were identified in a larger number in tumors ≤5 cm (p = 0.038). PD-L1-positive tumors had a higher number of immune cells, particularly CD3+, CD20+ and CD68+, in comparison to PD-L1-negative ones (p = 0.032, p = 0.051, p = 0.008). Epithelioid and mixed cell-type tumors had a higher number of CD68+ cells. Survival was not influenced by PD-L1 expression; instead, it was decreased in multifocal tumors (p = 0.0001) and in cases with Ki67 ≥ 50% (p = 0.008). Conclusions: PD-L1-positive expression and the presence of different immune cell types, in variable quantities, can contribute to a better understanding of the complex interactions between tumor cells and the microenvironment, with a possible therapeutic role in GISTs.

Correlation between imaging features on computed tomography and combined positive score of PD-L1 expression in patients with gastric cancer.

Objective: To explore the correlation between computed tomography (CT) features and combined positive score (CPS) of programmed cell death ligand 1 (PD-L1) expression in patients with gastric cancer (GC). Methods: This study reviewed an institutional database of patients who underwent GC operation without neoadjuvant chemotherapy between December 2019 and September 2020. The CPS results of PD-L1 expression of postoperative histological examination were recorded by pathology. Baseline CT features were measured, and their correlation with CPS 5 or 10 score groups of PD-L1 expression was analyzed. Results: Data for 153 patients with GC were collected. Among them, 124 were advanced GC patients, and 29 were early GC patients. None of the CT features significantly differed between CPS groups with a cutoff score of 5 and a score of 10 in patients with early GC. In advanced GC, the presence of lymph nodes with short diameters >10 mm was significantly different (P=0.024) between the CPS<5 and CPS≥5 groups. CT features such as tumor attenuation in the arterial phase, long and short diameter of the largest lymph node, the sum of long diameter of the two largest lymph nodes, the sum of short diameter of the two largest lymph nodes, and the presence of lymph nodes with short diameters >10 mm significantly differed between the CPS<10 and CPS≥10 groups in advanced GC. The sensitivity, specificity and area under receiver operating characteristic (ROC) curve of logistic regression model for predicting CPS≥10 was 71.7%, 50.0% and 0.671, respectively. Microsatellite instability (MSI) status was significantly different in CPS groups with cutoff score of 5 and 10 in advanced GC patients. Conclusions: CT findings of advanced GC patients with CPS≥10 showed greater arterial phase enhancement and larger lymph nodes. CT has the potential to help screen patients suitable for immunotherapy.

Distinct genomic landscapes of gastroesophageal adenocarcinoma depending on PD-L1 expression identify mutations in RAS-MAPK pathway and TP53 as potential predictors of immunotherapy efficacy.

BACKGROUND: The impact of molecular alterations on programmed death-ligand 1 (PD-L1) combined positive score (CPS) is not well studied in gastroesophageal adenocarcinomas (GEAs). We aimed to characterize genomic features of tumors with different CPSs in GEAs. PATIENTS AND METHODS: Genomic alterations of 2518 GEAs were compared in three groups (PD-L1 CPS ≥ 10, high; CPS = 1-9, intermediate; CPS < 1, low) using next-generation sequencing. We assessed the impact of gene mutations on the efficacy of immune checkpoint inhibitors (ICIs) and tumor immune environment based on the Memorial Sloan Kettering Cancer Center and The Cancer Genome Atlas databases. RESULTS: High, intermediate, and low CPSs were seen in 18%, 54% and 28% of GEAs, respectively. PD-L1 positivity was less prevalent in women and in tissues derived from metastatic sites. PD-L1 CPS was positively associated with mismatch repair deficiency/microsatellite instability-high, but independent of tumor mutation burden distribution. Tumors with mutations in KRAS, TP53, and RAS-mitogen-activated protein kinase (MAPK) pathway were associated with higher PD-L1 CPSs in the mismatch repair proficiency and microsatellite stability (pMMR&MSS) subgroup. Patients with RAS-MAPK pathway alterations had longer overall survival (OS) from ICIs compared to wildtype (WT) patients [27 versus 13 months, hazard ratio (HR) = 0.36, 95% confidence interval (CI): 0.19-0.7, P = 0.016] and a similar trend was observed in the MSS subgroup (P = 0.11). In contrast, patients with TP53 mutations had worse OS from ICIs compared to TP53-WT patients in the MSS subgroup (5 versus 21 months, HR = 2.39, 95% CI: 1.24-4.61, P = 0.016). CONCLUSIONS: This is the largest study to investigate the distinct genomic landscapes of GEAs with different PD-L1 CPSs. Our data may provide novel insights for patient selection using mutations in TP53 and RAS-MAPK pathway and for the development of rational combination immunotherapies in GEAs.

Prognostic value of PD-L1 combined positive score in patients with upper tract urothelial carcinoma.

PURPOSE: Upper tract urothelial carcinoma (UTUC) is relatively rare in Western countries. The impact of programmed death-ligand 1 (PD-L1) expression on UTUC remains unclear because previous studies have focused on bladder UC. We investigated the association of PD-L1 expression with clinicopathological features and prognosis in patients with UTUC. METHODS: We retrospectively reviewed the patients with UTUC that we treated at our institute from 2013 to 2018. In total, 105 patients with UTUC undergoing radical nephroureterectomy were analyzed to evaluate the PD-L1 expression on representative whole-tissue sections using the Combined Positive Score (CPS; Dako 22C3 pharmDx assay). A PD-L1 CPS ≥ 10 was considered positive. RESULTS: Among the 105 UTUC cases, 17.1% exhibited positive PD-L1 expression. A CPS ≥ 10 was significantly associated with higher tumor stage (≥ T2, p = 0.034) and lymph node invasion at diagnosis (p = 0.021). A multivariable analysis indicated that a CPS ≥ 10 was an independent prognostic predictor of shorter cancer-specific survival (hazard ratio [HR] = 4.59, 95% confidence interval [CI] = 1.66 - 12.7, p = 0.003) and overall survival (HR = 2.51, 95% CI = 1.19 - 5.27, p = 0.015). CONCLUSIONS: A PD-L1 CPS ≥ 10 in UTUC was associated with adverse pathological features and independently predicted worse cancer-specific and overall survival.

Programmed cell death protein 1/programmed death ligand 1 but not HER2 is a potential therapeutic target in gastric neuroendocrine carcinoma.

AIMS: Gastric neuroendocrine carcinoma (NEC) is a rare and aggressive subtype with a poor prognosis. We aim to investigate expression profiles of HER2 and programmed death ligand 1 (PD-L1) in gastric NEC to test the potential applicability of drugs targeting these molecules. METHODS AND RESULTS: Expression levels of HER2 and PD-L1 were evaluated in 25 gastric NECs, including 10 pure NECs and 15 mixed adenocarcinoma-NECs, and a combined positive score (CPS) was used to evaluate PD-L1 expression. The correlations of expression levels with both clinicopathological features and the expression of p53, retinoblastoma protein (Rb) and mismatch repair proteins were also analysed. Eighteen of the 25 (72%) cases showed a PD-L1 CPS of ≥ 1, which was previously shown to be associated with response to pembrolizumab. Positive nodal metastasis and low tumour-infiltrating lymphocyte (TIL) levels at the invasive margin were significantly associated with a PD-L1 CPS of < 1. The NEC component was HER2-negative in all cases, whereas HER2 positivity was observed in the adenocarcinoma component of six of 15 (40%) mixed adenocarcinoma-NECs. Mismatch repair deficiency, a mutant pattern of p53 expression and loss of Rb expression were observed in four (16%), 17 (68%) and nine (36%) cases, respectively, although these alterations were not associated with the PD-L1 CPS or other clinicopathological characteristics. CONCLUSIONS: HER2 is unlikely to be an effective target in gastric NEC owing to the lack of HER2 expression, whereas the PD-1/PD-L1 pathway is a potential therapeutic target for gastric NEC because of the relatively high prevalence of a PD-L1 CPS of ≥ 1 in this subtype.