Programmed Death Ligand 1 Testing Research Articles

Programmed Death Ligand 1 (PD-L1) Expression and its Association with Clinicopathologic Profile in Patients with Non-Small Cell Lung Cancer in a Philippine Tertiary Medical Center

Introduction. The current management of advanced non-small cell lung cancer (NSCLC) includes the characterization of Programmed Death Ligand-1 (PD-L1) expression for potential immune checkpoint inhibitor treatment. There is currently no available data regarding the patterns of PD-L1 expression in NSCLC, as well as their association with clinicopathologic profile in Filipino patients. Methodology. Clinicopathologic characteristics of 187 consecutive NSCLC clinical samples with PD-L1 testing using the clone 22C3 pharmaDx kit were collected. The presence of stromal tumor-infiltrating lymphocytes (TILs) were assessed in hematoxylin and eosin-stained slides. PD-L1 expression on tumor cells (TC) and stromal TILs were evaluated. Results. Of the 187 cases, there were 112 males and 75 females. The mean age at diagnosis was 66.4 years old (32-92 years old). It is composed of 131 cases of Adenocarcinoma, 15 Squamous cell carcinoma, 4 Adenosquamous carcinoma, 32 Non-small cell carcinoma, not otherwise specified, 3 poorly differentiated malignancy, 1 Large cell carcinoma, and 1 Mucinous carcinoma. Specimen types included 17 pleural fluid cell blocks, 60 tumor cell block samples, and 110 tissue biopsies. Tumor cell PD-L1 expression was identified in 59.1% of the 110 tissue biopsies. PD-L1 TPS for histologic specimens are as follows: TPS >50%, TPS 1-49%, and TPS <1% were observed in 23.6%, 35.5%, and 40.9% in our lung cancer cohort, respectively. Of the 77 cytology specimens, 50.6% presented with TC PD-L1 expression. TPS for this subgroup include: 49.4% with no PD-L1 expression, 35.1% with low PD-L1 expression, and 15.6% showing high PD-L1 expression. PD-L1 expression on TC did not correlate with age, sex, or histology for both specimen type subgroups. Stromal tumor-infiltrating lymphocytes were noted in 74.5% of tissue biopsies. Tumor cell block samples did not demonstrate stromal TILs. For tissue biopsies, female gender and TPS 1-49% were more likely to have <50% PD-L1 expression on TILs. Conclusion. Overall TC PD-L1 expression was observed in more than half (55.6%) of NSCLC patients in our cohort. The prognostic value of PD-L1 and clinical response to immune checkpoint inhibitors in the Filipino population needs to be further investigated.

PD-L1 Tumor Cell Expression in Upper Tract Urothelial Carcinomas is Associated With Higher Pathologic Stage.

Upper tract urothelial carcinomas (UTUCs) are a rare and unique subset of urothelial carcinoma (UC). Patients with UTUC may qualify for treatment with immune checkpoint inhibitors if their tumor cells express programmed death ligand-1 (PD-L1). While several large studies have looked at PD-L1 expression in UC, most have not investigated UTUC as a separate group, and most have not used Food and Drug Administration approved PD-L1 stains and scoring systems. Moreover, comparison between studies of PD-L1 expression is challenging as a wide variety of different PD-L1 antibody clones, testing platforms, and cutoff values have been used in the literature. This is a retrospective study of 37 cases of resected UTUC. Representative tissue from each case was compiled into tissue microarrays and immunohistochemical stains for PD-L1 (Dako antibody clones 22C3 and 28-8) were performed. PD-L1 staining was evaluated using several established Food and Drug Administration approved scoring systems: tumor proportion score (TPS), combined positive score, and immune cell score. Associations between PD-L1 expression and clinicopathologic features were investigated. Overall expression of PD-L1 in UTUC was 29.7% when using a TPS cutoff of ≥1%. Total of, 55.6% of cases with higher pathologic stage (pT3 or pT4) were positive for PD-L1, compared with only 5.3% of cases with lower pathologic stage (pTis, pT1, or pT2; P=0.0011). When using a combined positive score cutoff of ≥10, there was no significant association between tumor stage and PD-L1 expression. There was no association between PD-L1 positivity and tumor grade, tumor location, sex, or age. There was 100% concordance between 22C3 and 28-8 in terms of positivity rate. Our study using approved testing methods shows that PD-L1 expression in UTUC is more often associated with high pathologic stage, which may reflect an immune response evasion mechanism that UC cells acquire later in disease progression. In addition we show that 29.7% of UTUCs are positive for PD-L1 TPS expression, comparable to the 20% to 30% reported in UC literature. Finally, PD-L1 22C3 and 28-8 clones show similar overall patterns of staining in this setting.

PD-L1 expression in urothelial bladder cancer varies more among specimen types than between companion assays

Urothelial bladder cancer (UBC) patients ineligible to platinum-based chemotherapy can be treated with immune-checkpoint inhibitors (ICI) in Programmed Death Ligand 1 (PD-L1) positive cases. Although concordance exists between different PD-L1 assays, little is known on PD-L1 expression variability in matched UBC samples. We compared PD-L1 expression in whole slides of matched transurethral resections (TURBT), radical cystectomies (RC), and lymph node metastasis (LN). Immunohistochemistry using the VENTANA PD-L1 (SP263) assay was performed on 115 patients and scored positive if expression occurred in ≥25% immune cells (IC), ≥25% tumour cells (TC), or both. PD-L1 was positive in 42.7% TURBT, 39.8% RC, and 27.3% LN specimens. Concordance was moderate (κ=0.52; P<0.001) between TURBT and RC, and fair between LN and TURBT (κ=0.31; P=0.048) or RC (κ=0.25; P=0.075). Comparison with the VENTANA PD-L1 (SP142) assay which had been performed previously on the same cohort showed moderate to substantial inter-assay agreement (κ=0.42–0.66). Although TC staining is not part of the SP142 scoring algorithm, discordant PD-L1 assay outcome could be attributed to SP263 TC≥25% staining in only 41% of cases. These results show that PD-L1 expression variability between matched specimens is higher than that between individual assays. Optimal specimen determination for PD-L1 testing needs to be addressed in future studies.

Performance of Different Diagnostic PD-L1 Clones in Head and Neck Squamous Cell Carcinoma.

Background: The approval of immune checkpoint inhibitors in combination with specific diagnostic biomarkers presents new challenges to pathologists as tumor tissue needs to be tested for expression of programmed death-ligand 1 (PD-L1) for a variety of indications. As there is currently no requirement to use companion diagnostic assays for PD-L1 testing in Germany different clones are used in daily routine. While the correlation of staining results has been tested in various entities, there is no data for head and neck squamous cell carcinomas (HNSCC) so far.Methods: We tested five different PD-L1 clones (SP263, SP142, E1L3N, 22-8, 22C3) on primary HNSCC tumor tissue of 75 patients in the form of tissue microarrays. Stainings of both immune and tumor cells were then assessed and quantified by pathologists to simulate real-world routine diagnostics. The results were analyzed descriptively and the resulting staining pattern across patients was further investigated by principal component analysis and non-negative matrix factorization clustering.Results: Percentages of positive immune and tumor cells varied greatly. Both the resulting combined positive score as well as the eligibility for certain checkpoint inhibitor regimens was therefore strongly dependent on the choice of the antibody. No relevant co-clustering and low similarity of relative staining patterns across patients was found for the different antibodies.Conclusions: Performance of different diagnostic anti PD-L1 antibody clones in HNSCC is less robust and interchangeable compared to reported data from other tumor entities. Determination of PD-L1 expression is critical for therapeutic decision making and may be aided by back-to-back testing of different PD-L1 clones.

Molecular Biomarker and Programmed Death-Ligand 1 Expression Testing in Patients With Advanced Stage Non-small Cell Lung Cancer Across North Carolina Community Hospitals

Precision medicine in advanced non-small cell lung cancer (NSCLC) requires molecular biomarker testing in patients with nonsquamous and select patients with squamous histologies, and programmed death-ligand 1 (PD-L1) testing in both. What are rates of molecular and PD-L1 biomarker testing in patients with advanced NSCLC in community practices, and do rates vary by sociodemographic factors? What is the prevalence of molecular biomarker mutations and PD-L1 expression levels? From 389 stage IV NSCLC pathology reports obtained through the University of North Carolina Lineberger Comprehensive Cancer Center's Rapid Case Ascertainment Program from 38 community hospitals across North Carolina, we abstracted demographics, histology, molecular biomarker testing and results, and PD-L1 testing and expression. We geocoded patient and hospital addresses to determine travel time, distance to care, and census block level contextual variables. We compared molecular biomarker and PD-L1 testing rates, the prevalence of molecular biomarkers, and PD-L1 expression levels by race and sex, using χ2 tests. We determined predictors of testing, using multivariable logistic regression and report adjusted ORs and 95%CI. Among patients with nonsquamous NSCLC, 64.4%were tested for molecular biomarkers, and among all NSCLC patients 53.2%were tested for PD-L1 expression. Differences in biomarker testing rates by sociodemographic factors were not statistically significant in univariate or adjusted analyses. Adjusted analyses showed that patients living in areas with higher household internet access were more likely to undergo PD-L1 testing (adjusted OR= 1.66, 95%CI, 1.02-2.71). Sociodemographic differences in molecular biomarker prevalence and PD-L1 expression levels were not statistically significant, except for human epidermal growth factor receptor 2 (HER2) mutations, which occurred in 16.7%of males vs0%in females, P= .05. Biomarker testing remains underused in NSCLC. Future work should include larger populations and evaluate hospital-specific testing protocols to identify and address barriers to guideline-recommended testing.

Suitability of endobronchial ultrasound-guided transbronchial needle aspiration samples for programmed death ligand-1 testing in non-small cell lung cancer, the Bristol experience.

Treatment for non-small cell lung cancer (NSCLC) is now personalised using molecular mutation testing. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy suitability for anaplastic lymphoma kinase (ALK) and epidermal growth factor receptor (EGFR) mutation testing is established. Less is currently known about EBUS-TBNA suitability for PD-L1 (programmed death ligand-1) testing. To assess EBUS-TBNA biopsy adequacy for ALK, EGFR and PD-L1 testing, we conducted a prospective study of 279 consecutive NSCLC patients referred to a tertiary EBUS-TBNA centre in South West England. One hundred eight-four (62.6%) patients were found to have adenocarcinoma, 83 (28.2%) had squamous cell carcinoma, and 27 (9.2%) were identified as NSCLC-not otherwise specified. EGFR testing was successful in 166 of 168 patients (98.8%), ALK testing in all 115 and PD-L1 testing in 43 of 49 patients (88.2%). Previous EGFR and ALK testing did not affect biopsy PD-L1 testing success. PD-L1 testing failures occurred in three of five (60.0%) of 22G needle biopsies, one of five (20.0%) of 21G needle biopsies and two of 39 (5.1%) of 19G needle biopsies, P=.016. EBUS-TBNA biopsies are mostly suitable for PD-L1 testing. Larger needle size may improve PD-L1 (but not EGFR and ALK) testing success but requires further study in a controlled trial.

Clinicopathologic and Genomic Characterization of PD-L1 Positive Urothelial Carcinomas

Pembrolizumab was approved with an accompanying companion diagnostic (CDx) assay (PD-L1 DAKO 22C3) for urothelial carcinoma (UC). In this study, we further characterize the clinicopathologic and genomic features of UC that are programmed death-ligand 1 (PD-L1) positive. The cohort of this study consisted of a total of 528 consecutive UC patients with PD-L1 immunohistochemistry (IHC) and comprehensive genomic profiling (CGP). All PD-L1 IHC testing was performed using the DAKO 22C3 CDx assay for UC. PD-L1 positivity was determined at a combined positive score ≥ 10. A total of 44.5% (235/528) patients with UC were PD-L1positive . A lower PD-L1 positivity rate was detected in primary (42.3%, 148/350) versus metastatic sites (48.9%, 87/178). PD-L1 positivity was dependent on the location of the metastatic sites. CGP revealed PD-L1positive patients had more frequent genomic alterations (GAs) in TP53 (p = .006) and RB1 (p = .003) and less frequent GAs in FGFR3 (p = .001) and MTAP (p = .028). The APOBEC mutational signature and tumor mutational burden (TMB)-high were more common in PD-L1positive patients. By testing patients with UC with CGP, in addition to PD-L1 IHC, an additional 97 patients (18.4%) in the total cohort were eligible for immunotherapy based on TMB status. PD-L1positive and PD-L1negative urothelial carcinomas are genomically different. Also, our study provides the framework for future clinical investigation with regard to specimen site selection for PD-L1 testing as well as candidate biomarker genomic alterations that may predict for better response or lack of response to immune checkpoint inhibitors. In this study, a higher prevalence of TP53 and RB1 alterations and APOBEC mutational signatures in the PD-L1positive urothelial carcinoma disease subset and enrichment of FGFR3 alterations in the PD-L1negative disease subset were found. These data provide the basis for future investigation into the role of these genomic changes as positive and negative predictors of immunotherapy response. Also, differences wer seen in PD-L1 positivity based on the collection site of the sample, which can provide a framework for future clinical trial design and could influence sample selection for PD-L1 testing in patients with urothelial carcinoma when multiple samples are available.

Interpretation According to Clone-Specific PD-L1 Cutoffs Reveals Better Concordance in Muscle-Invasive Urothelial Carcinoma.

Because immune checkpoint inhibitors have been approved for treating advanced urothelial carcinoma (UC), programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) assays have been widely used as companion or complementary diagnostic tests for predicting treatment outcomes. Because different clones, scoring algorithms, and cutoffs have been used for interpretation, this study investigated the variation, correlation, and concordance of four validated PD-L1 clones (SP142, SP263, 22C3, and 28-8) and proposed a practical solution for the harmonization of PD-L1 IHC. A tissue microarray, including 46 muscle-invasive UCs, was constructed for PD-L1 testing with the four clones. Tumor cell (TC) and immune cell (IC) expression was analyzed. SP142 had significantly low TC expression, whereas SP263, 22C3, and 28-8 exhibited a moderate correlation (rho ≥ 0.6), with almost perfect concordance (intraclass correlation coefficient > 0.8) in TC expression. Fair to moderate correlation and concordance were observed in IC expression in most pairwise comparisons of clones. Substantial concordance (kappa > 0.6) was noted when high PD-L1 expression was defined by applying clone-specific cutoffs to each clone. Our findings imply that a universal cutoff value is not feasible for UC; we propose that PD-L1 IHC assays for UC should be interpreted according to a clone-specific scoring algorithm and cutoff value.

The importance of histological patterns on PD-L1 staining heterogeneity: Should we use pattern-based approach for selecting tumor samples for PD-L1 testing in lung adenocarcinomas?

Background/aimProgrammed death ligand-1 (PD-L1) is a predictive marker for immunotherapeutic agents. However, heterogeneous staining of PD-L1 can cause false-negative results. The aim of this study is to evaluate the importance of histological patterns on PD-L1 staining heterogeneity in lung adenocarcinomas (LAC). Materials and methods : PD-L1 immunohistochemistry (IHC) stain was performed to two different tissue cores of 128 LAC cases, and cut-off values are given for grouping the cases according to the percentage of staining (1%-10%, 11%-49%, 50%-100%). Staining rates between cores were compared and analyzed by their histological patterns. Also, the relation of the PD-L1 expression with the clinicopathological characteristics of the cases was analyzed. ResultsOverall, PD-L1 expression was observed in 53 of 128 cases (41.4%, 1% cut-off), 23.5% of them were positive at 10% cut-off and 14.1% at 50% cut-off. PD-L1 expression was significantly related to the high grade micropapillary and solid patterns of adenocarcinomas (p:0.01). Staining cut-offs were mostly similar between cores (43/50, 86%) (k:0.843). However, 14% of them were positive only in one core (7 of 50). This false negativity was mostly related to the histological patterns.ConclusionOur data reveal the heterogeneous staining of PD-L1 expression, also micropapillary and solid patterns show higher rates of PDL expression. Therewithal, these findings also highlight the importance of taking into consideration of histological patterns, when choosing a paraffin block for the PDL1.

PD-L1 Testing and Squamous Cell Carcinoma of the Head and Neck: A Multicenter Study on the Diagnostic Reproducibility of Different Protocols.

Simple SummaryThe introduction of therapies with immune checkpoint inhibitors targeting the programmed cell death protein 1 and its ligand (PD-L1) axis in head and neck squamous cell carcinoma prompted the need of reliable bio-selectors to stratify patients that would benefit from these treatments. The assessment of PD-L1 expression through immunohistochemistry represents the most widely used method to perform this task, being recently approved by regulatory authorities. However, borrowing from previous experiences in lung cancer, the heterogeneity of antibodies and platforms used in the routine clinical practice requires a strict multi-institutional harmonization effort. In this setting, the present study is aimed to assess the performances of different PD-L1 staining protocols and the inter-observer reliability for its interpretation.Immune checkpoint inhibitors for blocking the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis are now available for squamous cell carcinoma of the head and neck (HNSCC) in relapsing and/or metastatic settings. In this work, we compared the resulting combined positive score (CPS) of PD-L1 using alternative methods adopted in routine clinical practice and determined the level of diagnostic agreement and inter-observer reliability in this setting. The study applied 5 different protocols on 40 tissue microarrays from HNSCC. The error rate of the individual protocols ranged from a minimum of 7% to a maximum of 21%, the sensitivity from 79% to 96%, and the specificity from 50% to 100%. In the intermediate group (1 ≤ CPS < 20), the majority of errors consisted of an underestimation of PD-L1 expression. In strong expressors, 5 out of 14 samples (36%) were correctly evaluated by all the protocols, but no protocol was able to correctly identify all the “strong expressors”. The overall inter-observer agreement in PD-L1 CPS reached 87%. The inter-observer reliability was moderate, with an ICC of 0.774 (95% CI (0.651; 0.871)). In conclusion, our study showed moderate interobserver reliability among different protocols. In order to improve the performances, adequate specific training to evaluate PD-L1 by CPS in the HNSCC setting should be coordinated.

The prevalence of tumour markers in malignant pleural effusions associated with primary pulmonary adenocarcinoma: a retrospective study

ABSTRACT Background Oncological treatment of primary pulmonary adenocarcinoma (AC) includes drugs targeting the pathways involving programmed death-ligand 1 (PD-L1), epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK). The aim of the study was to report the prevalence of these tumour markers in pleural fluid with cytology positive for pulmonary AC and the potential influence of volume pleural fluid tested. Methods We retrospectively reviewed all thoracenteses performed in a two-year period at our interventional unit at Department of Respiratory Medicine at Zealand University Hospital Naestved, Denmark. ALK and PD-L1 testing was done using immunohistochemistry and EGFR testing using next-generation sequencing. We included pleural fluid specimens containing malignant cells originating from primary pulmonary AC and with at least one tumour marker requested by the clinicians. Results When screening 927 pleural fluid specimens, we identified 57 in accordance with the inclusion criteria. PD-L1, ALK and EGFR were obtained in 35/55 (64%), 38/57 (67%) and 26/47 (55%), respectively. The prevalence did not increase when analysing volumes > 50 mL (p = 0.21–0.58) Conclusion Tumour markers in pleural fluid specimens containing cells from pulmonary AC can be demonstrated in more than half of the cases. Therefore, supplementary invasive procedures than thoracentesis could potentially await these analyses.

PD-L1 testing based on theSP142 antibody in metastatic triple-negative breast cancer: summary of an expert round-table discussion.

Triple-negative breast cancer (TNBC) is more aggressive than other breast cancer subtypes. TNBC is characterized by increased expression of Programmed Death-ligand 1 (PD-L1), a signal used by many tumors to escape the immune response. Expression of PD-L1 is a positive predictor of response to immunotherapy; therefore, it should be investigated in TNBC in order to select patients who may benefit from anti-PD-L1 therapies. While many PD-L1 assays are available, only the VENTANA platform with the anti-PD-L1 (SP142) antibody is licensed as a companion diagnostic device for selecting patients with metastatic/advanced TNBC who are candidates for treatment with atezolizumab. In this article, we provide a summary of an expert round-table discussion about PD-L1 testing, using the SP142 antibody in metastatic TNBC.

Diffuse Large B Cell Lymphoma and Programmed Death-Ligand 1 Expression. a Clinical and Pathological Study of Patients Seen in Tawam Hospital UAE

Introduction: Diffuse Large B Cell Lymphoma (DLBL) is the most common type of Non-Hodgkin's Lymphoma (NHL) seen in Tawam hospital UAE. DLBL is a heterogenous disease arising either from a Germinal center (GC) or non- GCB cells. Molecular signature has identified 3 different groups of DLBL with significantly different prognosis (Primary mediastinal, Germinal center and Activated B Cell type). The therapy for DLBL has been without innovation since introduction of Rituximab more than 20 years ago and using R-CHOP. Attempts at improving the outcome has been uniformly unsatisfactory either by adding additional drugs, increasing the dose of drugs or deceasing the frequency of each cycle. New biomarkers and or targets are needed to improve the prognosis of patients with DLBL. Programmed Death-Ligand 1 (PDL1) has been shown to protect tumor cells by inducing T cell apoptosis (Dong et al., 2002). PDL1 targeting agents have been approved for many different types of malignancies including Hodgkin's Lymphoma. The role of PDL1 in DLBL is still under intense study. We report our findings of PDL1 expression in DLBL patients in UAE. Methods: Patients diagnosed with DLBL between December 1, 2019 till July 15th 2020. Patient records were reviewed in this study. Data was collected regarding patient demographics, clinical stage, International prognostic index (IPI), pathology and cell of origin {using immunohistochemistry (IHC) and Han's criteria}. PDL1 testing was performed by using FDA approved PharmaDx Dako Ab 22C3 kit for IHC on the gold standard Link 48 Dako platform. PDL1 expression was reported as Tumor proportion score (TPS). TPS in this assay was the percentage of viable tumor cells showing any perceptible partial or complete linear membranous (or membranous &amp; cytoplasmic) staining, in the large lymphoma cells. The specimen was considered PDL1 positive if the TPS was greater than or equal to 30%(Xu-Monette et al Blood 2018). All scores were reported by single pathologist Results Twenty-six patients were diagnosed with DLBL in the study period. The median age was 44 years (range 18-90 years). Majority of patients (75%) were less than sixty years of age. Advanced stage disease was seen in preponderance (66%) as compared to early stage (34%) while the LDH was elevated in 65 % patients (institutional normal &amp;lt; 225 IU per liter). Majority of patients (60%) were poor risk with IPI 3 or higher. Pathology review showed a uniformly elevated Ki 67 with the majority of specimens showing greater than 80 %. Molecular classification showed GCB type 50 % (n=13) as compared to non-GCB 42 % (n=11), data was not available for 2 patients. Epstein-Barr virus encoded small RNA (EBER) CISH was positive in only 3 patients (data was not available for 8 patients). PDL1 expression was tested in eighteen (GCB n=8, ABC n=10) patients. PDL1 expression was elevated in ABC type (90%) as compared GCB type (50 %) Fig 1. Conclusion The median age (44 years) is at least 2 decades less than the reported western cohort. Majority of the patients had high risk disease with advanced stage and IPI. Ki 67 was uniformly elevated (&amp;gt;80 % in 90 % of patients). There was a slight preponderance of GCB type (50 % vs 42%). PDL1 expression in ABC type DLBL was higher as compared to GCB. This observation needs to be validated in a larger cohort. Recent literature makes it very clear that ABC type DLBL has a poor outcome as compared to GCB type. PDL1 may offer an attractive target for treatment evaluation in ABC type DLBL. Figure Disclosures Alam: Pfizer:Honoraria;Roche:Honoraria.McCarthy:Karyopharm:Consultancy, Honoraria;Magenta:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board;Janssen:Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board;Takeda:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board;Juno Therapeutics, a Bristol-Myers Squibb Company:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board , Research Funding is to Roswell Park, Research Funding;AbbVie:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board;Genentech:Consultancy, Honoraria;Starton:Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board.

1987P Discordant genomic correlates of PD-L1 expression in lung adenocarcinoma among multiple cohorts using dissimilar PD-L1 testing techniques

Programmed death-ligand 1 (PD-L1) is a crucial biomarker predicting efficacious treatment of immune checkpoint inhibitors (ICIs). Understanding the genetic association of PD-L1 expression provides insights into the tumor-immune interaction and further exploration of immunotherapeutic biomarkers. However, the diverse and dissimilar quantifying assays might lead to inconsonant and confusing results, not conducive to the following research. Previous studies identified distinct staining utility among multiple PD-L1 antibodies, however, whether the genomic correlate of stained PD-L1 is also impacted by different testing assays is largely unknown. We evaluated 873 Chinese LUAD patients with lung adenocarcinoma in whom FDA-approved PD-L1 testing (22C3, Dako, Glostrup, Denmark; SP263, Ventana, Tucson, AZ) and targeted next-generation sequencing (3D Medicines Inc.) was performed on the same tissue. Data from Memorial Sloan Kettering Cancer Center (MSKCC), The Cancer Genome Atlas (TCGA) and the OAK trial were analyzed for further validation. In the 3DMed database (n=873), PD-L1 expression in tumor cells was positively correlated with tumor mutational burden. (p<0.001). PD-L1 positivity was more common in metastatic lymph nodes compared to primary lung tumors and other metastatic samples (p =0.009). Deleterious mutations in KRAS, TP53, ALK and MET significantly associated with PD-L1 high expression (each p<0.05) and EGFR and ERBB2 mutations associated with PD-L1 negativity (each p<0.05). Comparing the results in the 3DMed, MSKCC, TCGA, and OAK cohorts using different methods to quantifying PD-L1 expression, most of the positive results were validated in at least two cohorts, except ERBB2. Specific genomic features are associated with differential expression of PD-L1. The differed results related to STK11, ALK, and ERBB2 alterations might be on account of the distinction between PD-L1 testing techniques, laboratory-developed E1L3N method and FDA-approved SP263/22C3 assays, and the racial differences of LUAD between western and Chinese population. A large comparative study into the regulation of PD-L1 expression by these genes across races is warranted.

Immunotherapy Alone or in Combination with Chemotherapy as First-Line Treatment of Non-Small Cell Lung Cancer.

Immune checkpoint inhibitors (ICIs) have revolutionized the management of metastatic and selected cases of unresectable advanced non-small cell lung cancer (NSCLC). Importantly for patients, this implies that in the absence of a targetable oncogenic driver [especially epidermal growth factor receptor (EGFR) gene mutations and anaplastic lymphoma kinase (ALK) gene rearrangements] and in the presence of high programmed death-ligand 1 (PD-L1) expression (≥ 50%), they are eligible for mono-therapy with pembrolizumab thereby avoiding chemotherapy as the first line of treatment. This mono-immunotherapy approach for high PD-L1 metastatic NSCLC is associated with improved overall survival (OS) and radiological responses (RR) with lesser toxicity as compared with conventional platinum doublet chemotherapy for both non-squamous and squamous histological types.However, majority of NSCLC patients either have no or low expression of PD-L1 (< 50%) and such patients derive greater benefit from a combination of PD-1/PD-L1 ICIs with platinum doublet chemotherapy as compared with chemotherapy alone. Again, benefits are seen for both OS and RRs. However, combining immunotherapy with chemotherapy, in general, does lead to higher toxicity than those seen with either of the two alone.Additionally, for non-squamous NSCLC patients, clinicians should not initiate ICI treatment till the results of common targetable genetic alterations like EGFR mutation, ALK, and ROS1 gene rearrangement testing are known (preferably on broad next generation sequencing) and are negative (even if results of PD-L1 testing are available)-as targeted therapies remain the cornerstone of treatment for patients harboring these oncogenic drivers.It is worth mentioning that PD-1 and PD-L1 ICIs are very expensive, and their usage is associated with occurrence of immune-related adverse events (irAEs) which occasionally can be severe. Hence, it is important to discuss efficacy, toxicity, and cost-related to ICI treatment with each and every patient at diagnosis in order to help them decide if they are willing to go ahead with this form of therapy either singly (for high PD-L1 expressors) or in combination with chemotherapy (for others).

Expert consensus on PD-L1 expression testing in non-small-cell lung cancer in China

Cancer immunotherapy, especially the programmed death 1 (PD-1) and (or) programmed death ligand 1 (PD-L1) checkpoint inhibitors, has ushered in the modern oncology era and has achieved impressive success in the treatment of different tumors, including non-small-cell lung cancer (NSCLC). Yet, only a subset of patients achieved clinical benefit. Therefore, how to effectively screen the potential beneficiaries of PD-1 and (or) PD-L1 inhibitors has become a new challenge in the era of cancer immunotherapy. Clinical studies have shown that the expression level of PD-L1 in NSCLC is positively correlated with the efficacy of PD-1 and (or) PD-L1 inhibitors, and is one of the important predictive biomarkers. However, there are many challenges in PD-L1 testing. With the approving of various PD-1 and (or) PD-L1 inhibitors for immunotherapy setting of NSCLC, expert consensus of important issues regarding clinical significance of PD-L1 testing, testing time-point, as well as the standardization of PD-L1 testing procedure, including the PD-L1 testing operation steps, results' interpretation, quality control and so on, is of great significance for improving the accuracy of detection and reducing the difference between laboratories. On account to the practical questions of PD-L1 testing, this consensus was finally reached, which is based on the combination of literature, expert experience and internal discussion among committee members, in the hope of providing the guide for standardizing the PD-L1 testing and providing accurate and reliable result to screen the potential patients and predict clinical efficacy. It must be pointed out that in view of the existence of objective and complex factors of PD-L1 testing and the fact that the clinical application of PD-L1 testing is still at the early stage in China, there are still many issues need to be updated in near future based on further practice experience and research data.

Selected highlights of the 2019 Pulmonary Pathology Society Biennial Meeting: PD-L1 test harmonization studies.

Immune checkpoint inhibitors (ICI) including programmed death 1 (PD-1) inhibitors, such as nivolumab and pembrolizumab, or programmed death ligand 1 (PD-L1) inhibitors, such as atezolizumab and durvalumab, have recently emerged in advanced stage lung cancer as new standards of care. They are now indicated in first- line and second- or later-line treatment of metastatic or locally-advanced stage III non-small cell lung cancer (NSCLC), as well as for metastatic small cell lung cancer (SCLC), as single agent immunotherapy or in combination with chemotherapy. Four PD-L1 immunohistochemistry (IHC) assays have been established and validated in randomized trials, each for a specific ICI. They use different primary monoclonal antibodies, platforms and detection systems, as well as different scoring systems to assess PD-L1 expression either by tumor cells (TCs) and/or by infiltrating immune cells (ICs). Most studies have shown a close analytical performance of three of these clinically-validated standardized assays, but their use restricted to dedicated platforms, which are not all available in most laboratories, questions their applicability. In addition, the relative high costs of the assays have led to the development of in-house protocols in many pathology laboratories. Their use in clinical practice to assess the predictive value of PD-L1 expression for prescription of ICI raises the issue of their reliability and their validation as compared to standardized assays. This article discusses the main comparative studies available between LDT and assays, with clear evidence that LDT can reach a performance equivalent to the trial-validated assays. The requirements are an adequate validation as compared to an appropriate standard, and the participation to external quality assurance programs and training programs for PD-L1 IHC assessment for pathologists.

Different response to ALK inhibitors in EML4-ALK positive mediastinal cancer of unknown primary.

104 Background: With the development of next-generation sequencing (NGS) and precision medicine, targeted therapy especially molecule-driven therapy irrespective of tumor site may play an important role in cancer patients with druggable targets. Cancer of unknown primary (CUP) especially mediastinal CUP (MCUP) has poor prognosis with empirical chemotherapy but may harbor targetable genetic alterations. In the study, we evaluate the response to ALK inhibitors in ALK-positive MCUP. Methods: We queried the cancer database of the Second Xiangya hospitalfrom 2018.10 to 2019.12 for patients with ALK-positive cancers regardless of tumor site.Then we selected ALK-positive MCUP patients treated with ALK inhibitors, on which both NGS and programmed death-ligand 1 (PD-L1) testing were performed. Results: Forty-eightpatients with ALK-positive cancers were registered in the database. Two MCUP patients were found and showed different response. The first MCUP patient obtaining remarkable response to alectinib harbored ALK/TP53 co-mutation and TERT wild type accompanied by low PD-L1 expression, while the second one showing stable disease with crizotinib carried ALK/TP53/TERT co-mutation and high PD-L1 expression. Conclusions: We reveal for the first time that ALK inhibitors are applied to MCUP as first-line therapy and alectinib is firstly reported to treat MCUP patients. ALK inhibitor alectinib is expected to improve outcomes of patients with ALK-positive MCUP. NGS and PD-L1 testing should be recommended for MCUP to get more information about therapy and efficacy. [Table: see text]

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for PD-L1 Testing in Non-small Cell Lung Cancer

Programmed death-ligand 1 (PD-L1) expression on cancer cells is a clinically important biomarker to select patients with non-small cell lung cancer (NSCLC) for treatment with programmed death-1/PD-L1 inhibitors. Clinical trials of immunotherapy in patients with NSCLC have required histologic evidence for PD-L1 testing; in clinical practice, cytologic samples commonly are acquired in patients with advanced disease. This study aims to investigate whether endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples are adequate for PD-L1 testing in NSCLC. This study investigates the sampling adequacy of EBUS-TBNA for PD-L1 testing when compared with other methods. Furthermore, the relationship between clinicopathologic characteristics and PD-L1 expression in the study population have been examined. Five hundred seventy-seven NSCLC specimens were analyzed from consecutive patients with NSCLC across six centers in the United Kingdom and one center in the United States between January 2015 and December2016. In the EBUS-TBNA group (189 specimens), the overall percentage of patients with successful PD-L1 testing was 94.7%. There was no significant difference in sampling adequacy with other methods of tissue acquisition. Older patients had higher failure rates of PD-L1 testing (OR, 1.06; P= .008). In multivariate analysis, advanced N-stage (P= .048) and presence of brain metastasis (P< .001) were associated with high PD-L1 expression. This large multicenter study shows that EBUS-TBNA provides samples adequate for PD-L1 testing and that advanced N stage and the presence of brain metastasis are associated with high PD-L1 expression.

High tumor mutation burden is associated with DNA damage repair gene mutation in breast carcinomas

BackgroundImmunotherapy has demonstrated encouraging clinical benefits in patients with advanced breast carcinomas and Programmed death ligand 1 (PD-L1) expression has been proposed as an immunotherapy biomarker. Challenges with current PD-L1 testing exist and tumor mutation burden (TMB) is emerging as a biomarker to predict clinical response to immunotherapy in melanoma and non-small cell lung cancer patients. However, TMB has not been well characterized in breast carcinomas.MethodsThe study cohort included 62 advanced breast cancer patients (13 primary and 49 metastatic). Genetic alterations and TMB were determined by FoundationOne CDx next generation sequencing (NGS) and the association with clinicopathologic features was analyzed.ResultsHigh TMB was observed in a relatively low frequency (3/62, 4.8%). TMB levels were positively associated tumor infiltrating lymphocytes and significantly higher TMB was observed in breast carcinomas with DNA damage repair gene mutation(s). There was no significant association between TMB levels and other analyzed clinicopathologic characteristics.ConclusionsOur data indicate the importance of DNA damage repair proteins in maintaining DNA integrity and immune reaction and breast carcinoma patients with DDR mutation may benefit from immunotherapy.