PD-L1 assessment in lung cancer biopsies-pitfalls and limitations.

The programmed cell death-ligand 1 (PD-L1) protein expression on tumor cells predicts the efficacy of immunotherapy in patients with non-small cell lung cancer. However, the assessment of PD-L1 expression on tumor cells has limited power for selecting patients for immunotherapy due to intra-tumoral heterogeneity and inter-tumoral heterogeneity of PD-L1 expression, the inter-observer variability in scoring PD-L1 staining, and reproducibility. These difficulties and pitfalls in interpreting the PD-L1 assessment are discussed in detail in this review.

Cost-effectiveness analysis of atezolizumab as adjuvant treatment of patients with stage II-IIIA non-small cell lung cancer, PD-L1+≥50% of tumor cells in France: A modeling study.

INTRODUCTION: The objective of this study was to assess the cost-effectiveness of atezolizumab versus best supportive care (BSC) as adjuvant treatment following resection and platinum-based chemotherapy for patients with stage II-IIIA non-small cell lung cancer (NSCLC) whose tumours have a programmed death-ligand 1 (PD-L1) expression ≥ 50% of tumour cells and excluding those with ALK/EGFR mutations, from a French collective perspective. MATERIAL AND METHODS: A five state Markov model over a 20-year time horizon was considered, including disease-free survival (DFS1) from IMpower010 trial, three progression states (locoregional recurrence, first and second-line metastatic recurrence) and death. Utilities, quality-adjusted life year (QALY) decrements associated to adverse events, costs, resource use, and transition probabilities were considered in the model. These inputs were sourced from IMpower010 trial, literature, and clinical experts' opinion. Model uncertainty was assessed through deterministic, probabilistic sensitivity analyses and scenario analyses. RESULTS: Atezolizumab was associated with a QALY gain of 1.662, mainly driven by additional time spent in the DFS state, and a life-year gain of 2.112 years. The incremental cost-effectiveness ratio (ICER) for atezolizumab versus BSC was €21,348/QALY gained. The sensitivity analyses highlighted that uncertainty within the model had limited impact on results. Changing the DFS survival curves to other plausible distributions produced ICERs below €20,000/QALY. Introducing an increasing proportion of cured patients (91.5%) from year two to year five reduced the ICER to €13,083/QALY, while including a loss of efficacy at year two in the atezolizumab treatment arm increased the ICER to €33,755/QALY. DISCUSSION: Atezolizumab as adjuvant treatment in stage II-IIIA NSCLC resected patients with PDL1 ≥ 50% and without ALK/EGFR mutations has a lower ICER than other oncology drugs in France and a similar ICER to other adjuvant treatment in oncology.

Brain metastases in Japanese NSCLC patients: prognostic assessment and the use of osimertinib and immune checkpoint inhibitors-retrospective study.

BACKGROUND: The Graded Prognostic Assessment for lung cancer using molecular markers (Lung-molGPA) has not been validated for use with Japanese non-small cell lung cancer (NSCLC) patients with brain metastasis (BM) and the factors impacting survival need to be assessed. METHODS: We retrospectively analyzed 294 NSCLC patients who were newly diagnosed with BM between 2013 and 2020 and had received radiotherapy for BM initially at the Hokkaido Cancer Center. We evaluated the effect on the prognosis of Lung-molGPA items, the expression of PD-L1 (classified as high, low, and no expression), and the treatment history. The main outcome was the survival measured from the day of the diagnosis of BM, and log-rank tests were performed to evaluate the results. RESULTS: The median overall survival (OS) times for adenocarcinoma by groups of GPA scores (0‒1.0, 1.5‒2.0, 2.5‒3.0, and 3.5‒4.0) were 5.5, 14.8, 28.3, and 39.0 months (p < 0.0001), respectively. The median survival times for non-adenocarcinoma by groups of GPA scores (0‒1.0, 1.5‒2.0, and 2.5‒3.0) were 3.2, 11.0, and 16.0 months (p = 0.0011), respectively. In adenocarcinoma patients with gene mutations, osimertinib significantly improved the outcome (median OS: 34.2 and 17.6 months with and without osimertinib, respectively (p = 0.0164)). There was no significant difference in the OS between patients who were initially treated with tyrosine-kinase inhibitor for BM and those who initially received radiotherapy (p = 0.5337). In patients tested for PD-L1 expression, the median survival times after the diagnosis of BM were 5.6, 22.5, and 9.3 months for the high-, low- and no-expression groups (p = 0.2198), respectively. Also, in patients with high PD-L1 expressions, those with ICI had survival (median OS, 8.6 months) than those without (median OS, 3.6 months). CONCLUSIONS: We confirmed that Lung-molGPA successfully classified Japanese NSCLC patients with BM by the prognosis. Osimertinib prolonged survival of EGFR-positive NSCLC patients with BM, and ICI was effective in patients with high PD-L1 expressions.

Assessment of association between PD-L1 expression and clinicopathological characteristics of Indonesian patients with high grade bladder urothelial carcinoma.

INTRODUCTION: Urothelial carcinoma (UC) is the most common type of bladder cancer. One of the treatments that are currently being explored for UC involves the use of immune checkpoint inhibitors, especially those targeting PD-1/PD-L1 interaction. This interaction has been previously suggested to aid in the prediction of outcomes. This study was aimed to investigate PD-L1 expression in high grade UC cases in Indonesia, both at mRNA and protein levels, and assess its associated clinicopathological characteristics. MATERIALS AND METHODS: The study involved analysis of 51 formalin-fixed paraffin-embedded (FFPE) tissue samples, obtained from patients diagnosed with high grade UC. PD-L1 expression was measured using immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction. RESULTS: PD-L1 IHC staining was found to be positive in five (9.80%) cases. Upregulated expression of PD-L1 mRNA was reported in the patients belonging to older age group (p = 0.049) and mainly involved less invasive cases (p = 0.019), when compared with normoregulated group. Age was positively correlated with PD-L1 expression, as observed in IHC (r = 0.281, p = 0.046). In comparison to this, mitotic index was found to be inversely correlated with PD-L1 mRNA levels (r = -0.369, p = 0.008). CONCLUSION: IHC staining results showed that PD-L1 expression was lower as compared to previous studies, which might suggest poor response to anti PD-1/PD-L1 agents. The results of the study showed that higher mRNA levels were associated with lower proliferation and less invasive behavior. Thus, the study suggested the potential of PD-L1 mRNA levels to be used as a predictive factor for patient outcomes.

A simple, rapid and low-cost qPCR assay for evaluating the severity of exosomal PD-L1-mediated T cell exhaustion in blood samples.

A novel dual-aptamer activated proximity-induced qPCR assay was developed for the quantitative analysis of exosomal PD-L1 on T cell-exosome complexes in blood samples.

Comprehensive assessment of PD-L1 expression, tumor mutational burden and oncogenic driver alterations in non-small cell lung cancer patients treated with immune checkpoint inhibitors.

OBJECTIVES: Immune checkpoint inhibitors (ICIs) have proven to be effective treatment for lung cancer. However, a precise predictive immuno-oncology biomarker is still under development. We investigated the associations among PD-L1 expression, tumor mutational burden (TMB), and oncogenic driver alterations in advanced non-small cell lung cancer (NSCLC) patients treated with ICIs. MATERIALS AND METHODS: This multicenter cohort study included 1017 lung cancer patients. PD-L1 expression using four IHC assays (22C3, 28-8, SP263, SP142), TMB by whole-exome sequencing and oncogenic driver alterations were analyzed comprehensively. Clinical characteristics, treatment and survival data were collected. RESULTS: The results of 22C3 and 28-8 for PD-L1 expression showed acceptable concordance (k = 0.89; 95% confidence interval [CI], 0.87-0.92), and the clinical outcomes of ICIs classified according to PD-L1 expression by both assays were also approximately the same. There was slight concordance (k = 0.16; 95% CI, 0.11-0.22) between 22C3 and SP142, and high PD-L1 expression by SP142 was correspond to very high PD-L1 expressions by other assays. Patients with both high PD-L1 expression and high TMB showed a good response to ICIs with the response rate of 64% and median progression-free survival of 9.0 months despite of small population. Common EGFR or STK11 mutations showed a lower rate of high PD-L1 expression and a worse efficacy of ICIs and KRAS mutations had no negative impact on response to ICIs. CONCLUSION: Comprehensive assessment of PD-L1 expression, TMB, and oncogenic driver alterations would help to better predict the clinical outcomes of ICIs in NSCLC patients.

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.

Hepatoid adenocarcinoma of lung: A diagnostic challenge - Series of six cases with histopathological, predictive molecular and PD.L1 assessment.

Hepatoid adenocarcinoma of lung is a rare entity, accounting for 5% of all hepatoid adenocarcinoma. Distinguishing it from metastatic hepatocellular carcinoma is essential, but occasionally can be very challenging, especially with concurrent liver mass. A judicious immunohistochemical panel is warranted for accurate diagnosis and subsequent preservation of tissue for molecular testing. There is limited data on the mutational status, behavior and management strategies of this type of lung adenocarcinoma. We report largest series of six cases of hepatoid adenocarcinoma of lung citing the clinical, histopathological, immunohistochemical and molecular parameters including PD-L1 immunoexpression as a predictive biomarker for immunotherapy. None of the evaluated cases showed targetable mutation; however, four out of six cases showed significant PD-L1 expression. All the cases presented with advanced stage and received chemotherapy, however overall prognosis was dismal. In view of significant PD-L1 expression in these tumors and poor response to conventional chemotherapy, these cases might be considered for upfront immunotherapy.

Comprehensive assessment of PD-L1 and PD-L2 dysregulation in gastrointestinal cancers.

Background:PD-L1 and PD-L2 are ligands of PD-1. Their overexpression has been reported in different cancers. However, the underlying mechanism of PD-L1 and PD-L2 dysregulation and their related signaling pathways are still unclear in gastrointestinal cancers. Materials & methods: The expression of PD-L1 and PD-L2 were studied in The Cancer Genome Atlas and Genotype-Tissue Expression databases. The gene and protein alteration of PD-L1 and PD-L2 were analyzed in cBioportal. The direct transcription factor regulating PD-L1/PD-L2 was determined with ChIP-seq data. The association of PD-L1/PD-L2 expression with clinicopathological parameters, survival, immune infiltration and tumor mutation burden were investigated with data from The Cancer Genome Atlas. Potential targets and pathways of PD-L1 and PD-L2 were determined by protein enrichment, WebGestalt and gene ontology. Results: Comprehensive analysis revealed that PD-L1 and PD-L2 were significantly upregulated in most types of gastrointestinal cancers and their expressions were positively correlated. SP1 was a key transcription factor regulating the expression of PD-L1. Conclusion: Higher PD-L1 or PD-L2 expression was significantly associated with poor overall survival, higher tumor mutation burden and more immune and stromal cell populations. Finally, HIF-1, ERBB and mTOR signaling pathways were most significantly affected by PD-L1 and PD-L2 dysregulation. Altogether, this study provided comprehensive analysis of the dysregulation of PD-L1 and PD-L2, its underlying mechanism and downstream pathways, which add to the knowledge of manipulating PD-L1/PD-L2 for cancer immunotherapy.

Cutting Edge: Augmenting Muscle MHC Expression Enhances Systemic Pathogen Control at the Expense of T Cell Exhaustion.

Myocytes express low levels of MHC class I (MHC I), perhaps influencing the ability of CD8+ T cells to efficiently detect and destroy pathogens that invade muscle. Trypanosoma cruzi infects many cell types but preferentially persists in muscle, and we asked if this tissue-dependent persistence was linked to MHC expression. Inducible enhancement of skeletal muscle MHC I in mice during the first 20 d of T. cruzi infection resulted in enhanced CD8-dependent reduction of parasite load. However, continued overexpression of MHC I beyond 30 d ultimately led to a collapse of systemic parasite control associated with immune exhaustion, which was reversible in part by blocking PD-1:PD-L1 interactions. These studies demonstrate a surprisingly strong and systemically dominant effect of skeletal muscle MHC expression on maintaining T cell function and pathogen control and argue that the normally low MHC I expression in skeletal muscle is host protective by allowing for pathogen control while preventing immune exhaustion.

Immune checkpoint inhibitors of the PD-1/PD-L1-axis in non-small cell lung cancer: promise, controversies and ambiguities in the novel treatment paradigm.

Immune checkpoint inhibitors (ICIs) have received much attention not least for melanoma since the award of the Nobel prize in 2018. Here, we review the current state of knowledge about the use of these monoclonal antibodies (mAbs) in non-small cell lung cancer (NSCLC). These drugs have generally been conditionally approved on limited early data and there are few long-term follow-up data from randomized clinical trials. The effect observed for NSCLC thus far is, on average, moderately better than that obtained with chemotherapy. Severe side-effects are more common than might have been expected. The drugs themselves are expensive and are associated with time-consuming histopathologic testing even though the predictive value of these tests can be discussed. In addition, monitoring for side-effects involves increased workload and budgetary expense for clinical chemistry laboratories. Here, we review and summarize the current knowledge, controversies and ambiguities of ICIs for the treatment of NSCLC.

Regulatory perspectives on next-generation sequencing and complementary diagnostics in Japan.

INTRODUCTION: The 'one biomarker/one drug' scenario is unsustainable because cancer is a complex disorder that involves a number of molecular defects. In the past decade, major technological advances have lowered the overall cost and increased the efficiency of next-generation sequencing (NGS). AREAS COVERED: We review recent regulations on NGS and complementary diagnostics in Japan, mainly focusing on high-quality studies that utilized these new diagnostic modalities and were published within the last 5 years. We highlight significant changes in regulation, and explain the direction of efforts to translate the results of NGS and complementary diagnostics into clinical practice. EXPERT OPINION: NGS holds a number of advantages over conventional companion and complementary diagnostics that enable simultaneous analyzes of multiple cancer genes to detect actionable mutations. Parallel technological developments and regulatory changes have led to the rapid adoption of NGS into clinical practice. NGS-based genomic data have been leveraged to better understand the characteristics of a disease that affects its patient's response to a given therapy. As NGS-based tests become more widespread, however, Japanese authorities will face significant challenges particularly with respect to the complexity of genomic data, which will have to be managed if NGS is to benefit patients.

Adequate tumour cellularity is essential for accurate PD-L1 immunohistochemistry assessment on cytology cell-block specimens.

OBJECTIVES: PD-L1 immunohistochemistry (IHC) is an essential predictive biomarker for patients with non-small cell lung cancer (NSCLC), required to inform treatment decisions regarding anti-PD-1 immune checkpoint inhibitor therapy. This study aims to investigate the concordance between PD-L1 IHC assessed on NSCLC cytology and histology specimens and to determine the impactce of tumour cellularity. METHODS: Matched cytology and histology NSCLC specimens were retrieved from the archives of the Royal Melbourne Hospital and the Royal Prince Alfred Hospital. PD-L1 IHC was performed concurrently on both specimens at the Peter MacCallum Cancer Centre using the SP263 assay kit on the Ventana Benchmark Ultra staining platform and scored by two experienced pathologists. RESULTS: Overall agreement between matched cytology and histology specimens was good (intraclass correlation coefficient = 0.653, n = 58); however, markedly increased when the analysis was limited to cell-blocks with >100 tumour cells (intraclass correlation coefficient = 0.957, n = 29). Specificity at both 1% and 50% cut-offs was high regardless of cellularity; however, sensitivity decreased in samples with <100 tumour cells. CONCLUSIONS: PD-L1 IHC on cytology cell-block specimens in NSCLC is an acceptable alternative to histological specimens, provided adequate tumour cells are present. Clinicians and pathologists should be mindful of the risk of false negative PD-L1 IHC in samples with low tumour cellularity, to avoid excluding patients from potentially beneficial treatment.

Cost-Utility Analysis of Pembrolizumab Versus Chemotherapy as First-Line Treatment for Metastatic Non-Small Cell Lung Cancer With Different PD-L1 Expression Levels.

To evaluate the cost-utility of pembrolizumab versus chemotherapy as the first-line setting for metastatic non-small cell lung cancer (NSCLC) from the US health care system perspective, a Markov model was developed to compare the lifetime cost and effectiveness of pembrolizumab versus chemotherapy for untreated metastatic NSCLC, based on the clinical data derived from phase III randomized controlled trial (KEYNOTE-042; ClinicalTrials.gov; NCT02220894). Weibull distribution was fitted to simulate the parametric survival functions. Drug costs were collected from official websites, and utility values were obtained from published literature. Total costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) were computed as primary output indicators. The impact of different PD-L1 expression levels on ICER was also evaluated. One-way and probabilistic sensitivity analyses were performed to assess the model uncertainty. Compared with chemotherapy, patients treated with pembrolizumab provided an additional 1.13, 1.01, and 0.59 QALYs in patients with PD-L1 expression levels of ≥50%, ≥20%, and ≥1%, with corresponding incremental cost of 53,784, 47,479, and 39,827, respectively. The resultant ICERs of pembrolizumab versus chemotherapy were 47,596, 47,184, and 68,061/QALY, in three expression levels of PD-L1, respectively, all of which did not exceed the WTP threshold of 180,000/QALY. Probability sensitivity analysis outcome supported that pembrolizumab exhibited evident advantage over chemotherapy to be cost-effective. One-way sensitivity analysis found that ICERs were most sensitive to utility value of pembrolizumab in progression survival state. All the adjustment of parameters did not qualitatively change the result. For treatment-naive, metastatic NSCLC patients with PD-L1+, pembrolizumab was estimated to be cost-effective compared with chemotherapy for all PD-L1 expression levels at a WTP threshold of 180,000/QALY in the context of the US health care system.

Cost-Effectiveness Analysis of Upfront SBRT for Oligometastatic Stage IV Non-Small Cell Lung Cancer Based on Mutational Status.

OBJECTIVES: Current National Comprehensive Cancer Network (NCCN) guidelines support systemic therapy based on mutational status in stage IV non-small cell lung cancer (NSCLC), with stereotactic body radiation therapy (SBRT) reserved for oligoprogression. We aimed to evaluate the cost-effectiveness of the routine addition of SBRT to upfront therapy in stage IV NSCLC by mutational subgroup. MATERIALS AND METHODS: A Markov state transition model was constructed to perform a cost-effectiveness analysis comparing SBRT plus maintenance therapy with maintenance therapy alone for oligometastatic NSCLC. Three hypothetical cohorts were analyzed: epidermal growth factor receptor or anaplastic lymphoma kinase mutation-positive, programmed death ligand-1 expressing, and mutation-negative group. Clinical parameters were obtained largely from clinical trial data, and cost data were based on 2018 Medicare reimbursement. Strategies were compared using the incremental cost-effectiveness ratio with effectiveness in quality-adjusted life years (QALYs) and evaluated with a willingness to pay threshold of $100,000 per QALY gained. RESULTS: SBRT plus maintenance therapy was not cost-effective at a $100,000/QALY gained threshold, assuming the same survival for both treatments, resulting in an incremental cost effectiveness ratio of $564,186 and $299,248 per QALY gained for the epidermal growth factor receptor or anaplastic lymphoma kinase positive and programmed death ligand-1 positive cohorts, respectively. Results were most sensitive to the cost of maintenance therapy. A large overall survival gain with SBRT could potentially result in upfront SBRT becoming cost-effective. For the mutation-negative cohort, upfront SBRT was nearly cost-effective, costing $128,424 per QALY gained. CONCLUSION: Adding SBRT to maintenance therapy is not a cost-effective strategy for oligometastatic NSCLC compared with maintenance therapy alone for mutation-positive groups. However, this should be validated via randomized trials.

Cost-effectiveness analysis of pembrolizumab monotherapy and chemotherapy in the non-small-cell lung cancer with different PD-L1 tumor proportion scores.

OBJECTIVES: This study aimed to assess the cost-effectiveness of pembrolizumab monotherapy compared with chemotherapy as first-line treatment in patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC) with different tumor proportion scores (TPS), from perspectives of payers in China. MATERIALS AND METHODS: Basic information was derived from the KEYNOTE-042 trial. A Markov model was developed to simulate the process of NSCLC. Model inputs were based on published clinical trials and previous literatures. Costs were calculated from perspectives of payers in China. Sensitivity analyses were conducted to explore the impact of uncertainty. RESULTS: Treatment with pembrolizumab monotherapy for patients with high TPS (≥50%) was estimated to increase costs by $65,322 compared with chemotherapy, with a gain of 1.79 quality adjusted life years (QALYs) for an incremental cost-effectiveness ratio (ICER) of $36,493 per QALY. For patient population with TPS ≥ 20%, the ICER was $42,311 per QALY, while the corresponding ICER was $39,404 per QALY for patients with TPS ≥ 1%. Sensitive analyses for three different TPS populations were similar, which indicated the cost of PFS state in pembrolizumab arm and the price of pembrolizumab were the most influential factors in our study. CONCLUSION: ICERs yield by pembrolizumab monotherapy among different TPS populations were beyond the threshold we set, three times of the Gross Domestic Product per Capita of China in 2018 ($26,508/QALY). It is not a cost effective choice compared with standard chemotherapy for patients with locally advanced or metastatic NSCLC from the perspective of Chinese payer, regardless of TPS. Deeper discount of its current price would make pembrolizumab a preferable choice.

Toward improving prognosis prediction in patients undergoing small lung adenocarcinoma resection: Radiological and pathological assessment of diversity and intratumor heterogeneity.

OBJECTIVES: Prediction of prognosis based on the ground-glass opacity (GGO) ratio for small (≤2 cm) lung adenocarcinomas is not completely accurate. The aim of this study was to clarify the diversity of small adenocarcinomas and to identify ways to more accurately predict prognosis. MATERIALS AND METHODS: We retrospectively reviewed 62 patients (64 lesions) that underwent lobectomy for small (≤2 cm) lung adenocarcinoma. Proportions of histological components were measured and the presence of tumor spread through air spaces (STAS) was assessed. The correlations between GGO and histological components were examined. Furthermore, histological components of pure GGO lesions were analyzed using CT values. The intratumor heterogeneity of programmed death ligand 1 (PD-L1) expression was analyzed in 40 lesions. Furthermore, the relationship between CT/histological findings and prognoses was analyzed. RESULTS: In 13 pure GGO lesions, 7 (53.8%) lesions contained invasive components such as papillary, acinar, solid, and colloid. Tumor spread through air spaces (STAS) was also found in pure GGO lesions. Pure GGO lesions containing invasive components (p =  0.002) and STAS-positive lesions (p =  0.011) demonstrated strongly higher CT value. Differences in expression of PD-L1 among histological subtypes were observed in four of six (66.7%) PD-L1 positive lesions. Patients with papillary component, positivity for STAS, or CT value ≥ -140.6 Hounsfield units (HU) had significant poorer prognoses than patients without those in disease-free survival analyses (p =  0.007, p =  0.048, p = 0.012). Patients with the CT value < -383.4 HU and GGO ≥ 50% did not have recurrence. CONCLUSIONS: Invasive component and STAS can be present even in small GGO lesions, and patients with papillary components or STAS showed significantly poorer prognoses. STAS-positive lesions were strongly associated with a high CT value, and combined use of GGO ratio and CT value may be able to predict recurrences of lung cancer more accurately.

Heterogeneity analysis of PD-L1 expression and copy number status in EBUS-TBNA biopsy specimens of non-small cell lung cancer: Comparative assessment of primary and metastatic sites.

OBJECTIVES: Most patients with non-small cell lung cancer (NSCLC) are diagnosed at advanced stages where small biopsy specimens obtained through endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are sometimes the only available samples for diagnosis. We aimed to determine whether EBUS-TBNA specimens are suitable for the evaluation of PD-L1 protein expression and copy number alterations (CNAs). MATERIALS AND METHODS: PD-L1 protein expression and CNAs in 71 EBUS-TBNA specimens of NSCLC were assessed. Sixty-eight corresponding transbronchial biopsy (TBB) specimens from primary sites, thirteen resected primary tumors, and six resected metastases were comparatively analyzed. PD-L1 expression in tumor cells was assessed by immunohistochemistry (E1L3N). Positivity of ≥1% was used as the cutoff. PD-L1 CNAs were assessed with fluorescent in situ hybridization and were classified into three categories: amplification, polysomy, and disomy. Concordance between EBUS-TBNA and other specimens was calculated. RESULTS: The cohort comprised 48 men (67.6%), 15 never-smokers (21.1%), and 39 adenocarcinomas (54.9%). The concordance of PD-L1 positivity between EBUS-TBNA and other specimens was moderate; κ = 0.63 for EBUS-TBNA vs. TBB, κ = 0.68 for EBUS-TBNA vs. resected primary tumors, and κ = 1.0 for EBUS-TBNA vs. resected metastases. The concordance of PD-L1 CNA status was comparable with that of PD-L1 expression: κ = 0.60 for EBUS-TBNA vs. TBB and κ = 0.74 for EBUS-TBNA vs. resected primary tumors. When PD-L1 copy number was assessed as a continuous variable, the correlation of PD-L1 CNAs was superior to that of PD-L1 expression. Intratumorally, PD-L1 copy number was less heterogeneous than protein expression in whole sections of resected tumors. CONCLUSION: EBUS-TBNA specimens can be used to assess PD-L1 CNAs and protein expression. Although spatial heterogeneity should be considered for accurate interpretation, the evaluation of PD-L1 CNAs provides more reproducible results than that of protein expression levels especially with regard to intratumoral heterogeneity.