Fluorogenic enzyme-linked immunosorbent assay with a dual color variation

The development of accurate and high-throughput biomarker detection tools is crucial for the diagnosis, monitoring, and treatment of various diseases. In this study, a sensitive fluorogenic enzyme-linked immunosorbent assay (FELISA) using Amplex Red or QuantaBlu fluorescent substrate was developed for the detection of tumor necrosis factor alpha and programmed cell death-ligand 1. The limit of detection of FELISA was in the nanogram order and multiple samples were conveniently assayed within 20 h using FELISA, demonstrating its applicability as a powerful immunoassay tool. FELISA can be widely used for rapid and accurate TNFα and PDL1 detection and applied to various fluorogenic immunoassays against other antigens of interest.

Genomic Landscape of Pulmonary Sarcomatoid Carcinoma

PURPOSE

Pulmonary sarcomatoid carcinoma (PSC) is a rare aggressive subtype of non-small cell lung cancer (NSCLC) with limited therapeutic strategies. We attempted to elucidate the evolutionary trajectories of PSC using multiregional and longitudinal tumor samples.

MATERIALS AND METHODS

A total of 31 patients were enrolled in this study and 11 longitudinal samples were available from them. Using whole exome sequencing data, we analyzed the mutational signatures in both carcinomatous and sarcomatous areas in primary tumors of the 31 patients and longitudinal samples obtained from 11 patients. Furthermore, digital droplet polymerase chain reaction (ddPCR), and programmed death-ligand 1 (PD-L1) immunohistochemistry using the Ventana SP263 assay were performed.

RESULTS

TP53 was identified as the most frequently altered gene in the primary (74%) and metastatic (73%) samples. MET exon 14 skipping mutations, confirmed by ddPCR, and TP53 mutations were mutually exclusive; whereas, MET exon 14 skipping mutations frequently co-occurred with MDM2 amplification. Metastatic tumors showed dissimilar genetic profiles from either primary component. During metastasis, the signatures of APOBEC decreased in metastatic lesions compared with that in primary lesions. PSC showed higher MET and KEAP1 mutations and stronger PD-L1 protein expression compared with that recorded in other NSCLCs.

CONCLUSION

Decreased APOBEC signatures and subclonal diversity were detected during malignant progression in PSC. Frequent MET mutations and strong PD-L1 expression distinguished PSC from other NSCLCs. The aggressiveness and therapeutic difficulties of PSC were possibly attributable to profound intratumoral and intertumoral genetic diversity. Next-generation sequencing could suggest the appropriate treatment strategy for PSC.

A self-assembly active nanomodulator based on berberine for photothermal immunotherapy of breast cancer via dual regulation of immune suppression

Breast cancer (BC) remains a significant global health concern, especially affecting women, necessitating the development of effective treatment strategies. Photothermal immunotherapy has holds promise for addressing BC by eradicating tumors, preventing metastasis, and reducing recurrence rates. However, the dynamic amplification of indoleamine 2,3-dioxygenase 1 (IDO-1) and programmed cell death-ligand 1 (PD-L1) triggered by photothermal therapy (PTT) poses presents a significant barrier to immune cell infiltration, thus promoting immune evasion. To enhance overall efficiency, a hyaluronic acid (HA)-coated berberine (BBR)-indocyanine green self-assembly active nano modulator (HBI NDs) was successfully developed. This nano modulator aims to reverse immune resistance and further contribute to the synergistic anti-tumor effects. The prepared HBI NDs demonstrated a uniform spherical morphology, high drug loading, and favorable optical properties. The results based on in vitro cell experiments and tumor animal models confirmed that HBI NDs selectively accumulated in tumor tissues, downregulated PD-L1 and IDO-1 protein expression, and induced elevated cell apoptosis. Consequently, these effects result in efficient immune infiltration and positive anti-tumor outcomes. In conclusion, the HBI NDs nanodrug exhibits considerable potential as a novel agent for enhancing anticancer efficacy and promoting immune infiltration.

Immune signature of small bowel adenocarcinoma and the role of tumor microenvironment

In this editorial we comment on the article published "Clinical significance of programmed cell death-ligand expression in small bowel adenocarcinoma is determined by the tumor microenvironment". Small bowel adenocarcinoma (SBA) is a rare gastrointestinal neoplasm and despite the small intestine's significant surface area, SBA accounts for less than 3% of such tumors. Early detection is challenging and the reason arises from its asymptomatic nature, often leading to late-stage discovery and poor prognosis. Treatment involves platinum-based chemotherapy with a 5-fluorouracil combination, but the lack of effective chemotherapy contributes to a generally poor prognosis. SBAs are linked to genetic disorders and risk factors, including chronic inflammatory conditions. The unique characteristics of the small bowel, such as rapid cell renewal and an active immune system, contributes to the rarity of these tumors as well as the high intratumoral infiltration of immune cells is associated with a favorable prognosis. Programmed cell death-ligand 1 (PD-L1) expression varies across different cancers, with potential discrepancies in its prognostic value. Microsatellite instability (MSI) in SBA is associated with a high tumor mutational burden, affecting the prognosis and response to immunotherapy. The presence of PD-L1 and programmed cell death 1, along with tumor-infiltrating lymphocytes, plays a crucial role in the complex microenvironment of SBA and contributes to a more favorable prognosis, especially in the context of high MSI tumors. Stromal tumor-infiltrating lymphocytes are identified as independent prognostic indicators and the association between MSI status and a favorable prognosis, emphasizes the importance of evaluating the immune status of tumors for treatment decisions.

Pembrolizumab With or Without Lenvatinib for First-Line Metastatic NSCLC With Programmed Cell Death-Ligand 1 Tumor Proportion Score of at least 1% (LEAP-007): A Randomized, Double-Blind, Phase 3 Trial

INTRODUCTION

Lenvatinib plus pembrolizumab was found to have antitumor activity and acceptable safety in previously treated metastatic NSCLC. We evaluated first-line lenvatinib plus pembrolizumab versus placebo plus pembrolizumab in metastatic NSCLC in the LEAP-007 study (NCT03829332/NCT04676412).

METHODS

Patients with previously untreated stage IV NSCLC with programmed cell death-ligand 1 tumor proportion score of at least 1% without targetable EGFR/ROS1/ALK aberrations were randomized 1:1 to lenvatinib 20 mg or placebo once daily; all patients received pembrolizumab 200 mg every 3 weeks for up to 35 cycles. Primary end points were progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors version 1.1 and overall survival (OS). We report results from a prespecified nonbinding futility analysis of OS performed at the fourth independent data and safety monitoring committee review (futility bound: one-sided p < 0.4960).

RESULTS

A total of 623 patients were randomized. At median follow-up of 15.9 months, median (95% confidence interval [CI]) OS was 14.1 (11.4‒19.0) months in the lenvatinib plus pembrolizumab group versus 16.4 (12.6‒20.6) months in the placebo plus pembrolizumab group (hazard ratio = 1.10 [95% CI: 0.87‒1.39], p = 0.79744 [futility criterion met]). Median (95% CI) PFS was 6.6 (6.1‒8.2) months versus 4.2 (4.1‒6.2) months, respectively (hazard ratio = 0.78 [95% CI: 0.64‒0.95]). Grade 3 to 5 treatment-related adverse events occurred in 57.9% of patients (179 of 309) versus 24.4% (76 of 312). Per data and safety monitoring committee recommendation, the study was unblinded and lenvatinib and placebo were discontinued.

CONCLUSIONS

Lenvatinib plus pembrolizumab did not have a favorable benefit‒risk profile versus placebo plus pembrolizumab. Pembrolizumab monotherapy remains an approved treatment option in many regions for first-line metastatic NSCLC with programmed cell death-ligand 1 tumor proportion score of at least 1% without EGFR/ALK alterations.

Novel Programmed Death Ligand 1-AKT-engineered Mesenchymal Stem Cells Promote Neuroplasticity to Target Stroke Therapy

Although tissue plasminogen activator (t-PA) and endovascular thrombectomy are well-established treatments for acute ischemic stroke, over half of patients with stroke remain disabled for a long time. Thus, a significant unmet need exists to develop an effective strategy for treating acute stroke. We developed a combination of programmed cell death-ligand 1 (PD-L1) and AKT-modified umbilical cord mesenchymal stem cells (UMSC-PD-L1-AKT) implanted through intravenous (IV) and intracarotid (IA) routes to enhance therapeutic efficacy in a murine stroke model for overcoming the hypoxic environment of the ischemic brain, to prolong stem cell survival, and to attenuate systemic inflammation to protect neuroglial cells from ischemic injury. Higher cellular proliferation and survival upon exposure to toxic agents were observed in UMSC-PD-L1-AKT cells than in UMSCs in vitro. Moreover, increased attenuation of CFSE+ cell proliferation and increased survival of primary cortical cells were verified by the interaction with UMSC-PD-L1-AKT. Consistently, dual-route administration (IV + IA) of UMSC-PD-L1-AKT resulted in a significant reduction in infarction volume and improvement of neurological dysfunction in a stroke model. Furthermore, enhancing CD8+CD122+IL-10+ T-regulatory (Treg) cells and reducing CD11b+CD80+ microglial/macrophages and CD3+CD8+TNF-α+ and CD3+CD8+ IFN-α+ cytotoxic T cells induced an anti-inflammatory microenvironment to protect neuroglial cells in the ischemic brain. Collectively, therapeutic intervention using UMSC-PD-L1-AKT could provide a niche for inducing neuroplastic regeneration in brains after stroke.

Clinical significance of programmed cell death-ligand expression in small bowel adenocarcinoma is determined by the tumor microenvironment

BACKGROUND

Comprehensive genomic analysis has shown that small bowel adenocarcinoma (SBA) has different genomic profiles from gastric and colorectal cancers. Hence, it is essential to establish chemotherapeutic regimens based on SBA characteristics. The expression of programmed cell death-ligand 1 (PD-L1) and programmed cell death-ligand 2 (PD-L2) in SBA is not fully understood. Anti-PD-L1/PD-1 therapy uses tumor-infiltrating lymphocytes (TILs); therefore, the status of TILs in the tumor microenvironment (TME) may influence their efficacy. The ratio of FoxP3+ to CD8+ T cells has been reported to be useful in predicting the prognosis of digestive system cancers.

AIM

To investigate the clinicopathological significance of PD-L1/2 expression according to the status of TILs in SBA tissues.

METHODS

We performed immunohistochemical analysis for PD-L1, PD-L2, CD8, FoxP3, and DNA mismatch repair (MMR) proteins using formalin-fixed, paraffin-embedded tissues from 50 patients diagnosed with primary SBA. The immunoreactivities of PD-L1 and PD-L2 were determined separately in tumor cells and tumor-infiltrating immune cells throughout the tumor center and invasive margins, and finally evaluated using the combined positive score (CPS). We assessed CD8+ and FoxP3+ T cells in the intratumoral and tumor-surrounding stroma. Subsequently, we calculated and summed the ratio of FoxP3 to CD8+ T cell counts. Immune-related cell densities were graded as low or high. Immunohistochemical results were compared with clinicopathological factors and patient prognosis. The distribution of cancer-specific survival (CSS) was estimated using the Kaplan-Meier method, and the log-rank test was used to test for significant differences in CSS. A Cox proportional hazard model was also used to assess the effect of tumor variables on CSS.

RESULTS

PD-L1 expression was positive in 34% in tumor cells (T-PD-L1) and 54% in tumor-infiltrating immune cells (I-PD-L1) of the cases examined. T-PD-L2 was positive in 34% and I-PD-L2 was positive in 42% of the cases. PD-L1 CPS ≥ 10 and PD-L2 CPS ≥ 10 were observed in 50% and 56% of the cases, respectively. Deficient MMR (dMMR) was 14% of the cases. T-PD-L1, I-PD-L1 and PD-L1 CPS ≥ 10 were all significantly associated with dMMR (P = 0.037, P = 0.009, and P = 0.005, respectively). T-PD-L1, I-PD-L1, and PD-L1 CPS ≥ 10 were all associated with deeper depth of invasion (P = 0.001, P = 0.024, and P = 0.002, respectively). I-PD-L2 expression and PD-L2 CPS ≥ 10 were significantly higher in the differentiated histological type (P = 0.015 and P = 0.030, respectively). The I-PD-L1 and I-PD-L2 levels were significantly associated with better CSS (P = 0.037 and P = 0.015, respectively). CD8-high was significantly associated with less lymph node metastasis (P = 0.047), less distant metastasis (P = 0.024), less peritoneal dissemination (P = 0.034), and earlier TNM stage (P = 0.047). The CD8-high group had better prognosis than the CD8-low group (P = 0.018). FoxP3 expression was not associated with any clinicopathological factors or prognosis. We found that patients with PD-L2 CPS ≥ 10 tended to have worse prognosis in the FoxP3/CD8-low group (P = 0.088).

CONCLUSION

The clinicopathological significance of PD-L1/2 expression may differ depending on the TME status. Immune checkpoint inhibitors may improve the prognosis of SBA patients with low FoxP3/CD8 ratio and PD-L2 expression.

Prognostic role and clinical significance of tumor-infiltrating lymphocyte (TIL) and programmed death ligand 1 (PD-L1) expression in gastric cancer: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

This study intended to evaluate the prognostic effects of programmed death-ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in survival and their associations with clinicopathological characteristics in patients with gastric cancer.

METHODS

PubMed, Scopus, ProQuest, Web of Science, and Ovid databases were searched to obtain the relevant studies. Eleven studies with 2298 patients were included in this study.

RESULTS

Like the level of TILs, there were no significant associations between PD-L1 expression and TNM stage, lymph node metastasis, vascular invasion, and tumor location (All p values ≥ 0.05). Furthermore, there was no significant association between PD-L1 expression with overall survival (OS) (HR = 0.76, 95% CI: 0.55 to 1.05, p value = 0.10) and disease-free survival (DFS) (HR = 0.62, 95% CI: 0.10 to 3.68, p value = 0.59). In the assessment of TILs presence and survival association, the analysis showed no association between TILs presence and overall survival (OS) (HR = 0.95, 95% CI: 0.62 to 1.45).

CONCLUSIONS

In conclusion, the study has revealed no prognostic effect of PD-L1 and TILs in gastric cancer patients.

Intratumor heterogeneity is associated with less CD8+ T cell infiltration and worse survival in patients with small cell lung cancer

PURPOSE

Small cell lung cancer (SCLC) is a heterogeneous malignancy with genetic and phenotypic disparity. However, the association between intratumor heterogeneity (ITH) and immunological features as well as the impact of ITH on prognosis has never been explored in SCLC. Hence, we investigated the relationship between ITH and their immunological features and explored the effect of ITH on overall survival (OS) in patients with SCLC.

METHODS

Programmed cell death-ligand 1 (PD-L1), CD8⁺ cell infiltration was calculated through immunohistochemical staining and tumor mutational burden (TMB), tumor neoantigen burden (TNB), and ITH levels via whole-exome sequencing (WES).

RESULTS

Significant correlation was not found in ITH versus TMB, ITH versus TNB (P = 0.1821, P = 0.0612). No significant variation in ITH was found between negative PD-L1 SCLC patients and positive PD-L1 ones (P = 0.0610 for TPS, P = 0.6347 for CPS). Interestingly, we demonstrated the negative correlation between CD8⁺ T cell infiltration and ITH (P = 0.0220). More importantly, significant OS benefit was detected in ITH-low SCLC patients in comparison with ITH-high ones (P = 0.0049). ITH was an independent prognostic factor on OS with clinicopathological variables adjusted (HR, 2.044; 95% CI 1.190-3.512; P = 0.010). We also demonstrated significantly different driver genes and CNV between ITH-low and ITH-high SCLC.

CONCLUSION

Our work pointed the negative association of ITH with CD8⁺ T cell infiltration and suggested ITH as a potential predictor of OS in SCLC, putting forward a direction for more precise and individualized therapeutic strategies for SCLC.

[Pathological features and immune microenvironment in HER-2 intratumoral heterogeneous breast cancers]

Objective: To observe the clinical pathology features, and immune microenvironment of HER-2 intratumoral heterogeneity breast cancer. Methods: Thirty cases of HER-2 intratumoral heterogeneous breast cancer were retrospectively analyzed in Tianjin Medical University Cancer Institute and Hospital from November 2017 to June 2020. HER-2 expression was detected by immunohistochemistry and verified by dual color silver-enhanced in-situ hybridization (D-SISH). HER-2 intratumoral positive and negative regions were divided. The pathological characteristics, subtype, and the level of tumor infiltrating lymphocytes (TILs) and the expression of programmed cell death-ligand 1 (PD-L1) were evaluated respectively. Results: The proportion of HER-2 positive cells of the breast cancer ranged from 10% to 90%. The pathological type was mainly invasive non-special typecarcinoma. Six cases presented different pathological types between HER-2 positive and negative regions. The HER-2-positive areas included 2 cases of carcinoma with apocrine differentiation, and the negative areas included 2 cases of invasive micropapillary carcinoma, 1 case of invasive papillary carcinoma, and 1 case of carcinoma with apocrine differentiation. In HER-2 positive regions, 17 cases were Luminal B and 13 cases were HER-2 overexpressed types. There were 22 cases of Luminal B and 8 cases of triple negative tumors in the HER-2 negative areas. The levels of TILs in HER-2 positive and negative areas accounted for 53.3% (16/30) and 26.7% (8/30), respectively, with a statistically significant difference (P=0.035). The positive expression of PD-L1 in HER-2 positive area and HER-2 negative area were 6 cases and 9 cases, respectively. Among 8 cases with HER-2 negative regions containing triple negative components, 4 cases were positive for PD-L1 expression. Conclusions: In the case of HER-2 intratumoral heterogeneity, it is necessary to pay attention to both HER-2 positive and negative regions, and evaluate subtype separately as far as possible. For HER-2 intratumoral heterogeneous breast cancer containing triple negative components, the treatment mode can be optimized by refining the intratumoral expression of PD-L1.

Integrative prognostic analysis of tumor-infiltrating lymphocytes, CD8, CD20, programmed cell death-ligand 1, and tertiary lymphoid structures in patients with early-stage triple-negative breast cancer who did not receive adjuvant chemotherapy

PURPOSE

Stromal tumor-infiltrating lymphocytes (TILs) are independent prognostic factors in systemically untreated early-stage triple-negative breast cancer (TNBC). Other immune biomarkers including CD8, CD20, programmed cell death-ligand 1 (PD-L1), and tertiary lymphoid structures (TLS) are also reported to be associated with prognosis. However, whether combining other immune biomarkers with TILs would allow for further prognostic stratification is unknown.

METHODS

We retrospectively analyzed 125 patients with early-stage TNBC not receiving perioperative chemotherapy. Stromal TILs and TLS were evaluated on hematoxylin-eosin slides. PD-L1 expression was evaluated using the SP142 assay. CD8 and CD20 were assessed by immunohistochemistry and counted by digital pathology.

RESULTS

Immune biomarker levels were positively correlated (p < 0.001). Adding CD8 and PD-L1 to multivariable analysis including clinicopathological factors (stage and histological grade) and TILs significantly improved the prognostic model (likelihood ratio χ² = 9.24, p = 0.01). In Cox regression analysis, high CD8 was significantly associated with better prognosis [hazard ratio (HR) 0.69, 95% confidence interval (CI) 0.48-0.98, p = 0.04], and PD-L1 positivity was significantly associated with worse prognosis (HR 4.33, 95%CI 1.57-11.99, p = 0.005). Patients with high CD8/PD-L1 (-) tumors had the most favorable prognosis [5 year invasive disease-free survival (iDFS), 100%], while patients with low CD8/PD-L1( +) tumors had the worst prognosis (5 year iDFS, 33.3%).

CONCLUSION

CD8 and PD-L1 levels add prognostic information beyond TILs for early-stage TNBC not receiving perioperative chemotherapy. CD8-positive T cells and PD-L1 may be useful for prognostic stratification and in designing future clinical trials of TNBC.

Sequence-specific 1H, 13C and 15N backbone NMR assignments for the N-terminal IgV-like domain (D1) and full extracellular region (D1D2) of PD-L1

The co-inhibitory immune checkpoint interaction between programmed cell death-protein 1 (PD-1) and programmed cell death-ligand 1 (PD-L1) serves to regulate T-cell activation, promoting self-tolerance. Over-expression of PD-L1 is a mechanism through which tumour cells can evade detection by the immune system. Several therapeutic antibodies targeting PD-L1 or PD-1 have been approved for the treatment of a variety of cancers, however, the discovery and development of small-molecule inhibitors of PD-L1 remains a challenge. Here we report comprehensive sequence-specific backbone resonance assignments (¹H, ¹³C, and ¹⁵N) obtained for the N-terminal IgV-like domain of PD-L1 (D1) and the full two domain extracellular region (D1D2). These NMR assignments will serve as a useful tool in the discovery of small-molecule therapeutics targeting PD-L1 and in the characterisation of functional interactions with other protein partners, such as CD80.

Treatment of gastric carcinoma with lymphoid stroma by immunotherapy: A case report

BACKGROUND

Gastric cancer with lymphoid stroma (GCLS) is a rare type of gastric cancer characterized by abundant lymphocytic infiltration of the stroma. It is an Epstein-Barr virus-associated gastric cancer with a better prognosis than typical gastric cancer but with similar symptoms. GCLS diagnosis is based on pathological, histological and immunohistochemical examination and there are no standardized guidelines for treatment.

CASE SUMMARY

This case report describes a 72-year-old man with a 6-mo history of abdominal pain. Endoscopy revealed ulcerative lesions in the stomach and gastric cancer was suspected. A preoperative endoscopic biopsy indicated undifferentiated carcinoma and postoperative pathological, histological and immunohistochemical analyses of the resected specimen confirmed a final diagnosis of GCLS.

CONCLUSION

The patient showed high programmed cell death-ligand 1 expression and recovered well after immunotherapy.

Inter-assay reliability of programmed cell death-ligand 1 in head and neck squamous cell carcinoma

OBJECTIVES

The programmed cell death-ligand 1 (PD-L1) 22C3 pharmDx assay is used as a companion diagnostic test to select head and neck squamous cell carcinoma (HNSCC) patients that may benefit from treatment with the checkpoint inhibitor pembrolizumab. Because the Dako platform is not universally available, we studied the performance of a 22C3 laboratory developed test (LDT) performed on a Ventana BenchMark Ultra compared to the 22C3 pharmDx assay.

MATERIALS AND METHODS

Serial sections from tissue micro arrays (TMAs) containing tumour tissue from 97 HNSCC patients were stained with the 22C3 pharmDx assay and 22C3 LDT. All TMA cores were scored by three dedicated head and neck pathologists for PD-L1 expression.

RESULTS

Substantial interobserver agreement was reported for both the standardized 22C3 pharmDx assay and the 22C3 LDT (respectively Fleiss' κ 0.62, 95% CI 0.57-0.67 and 0.63, 95% CI 0.58-0.68). Concordance between the assays was almost perfect on core and patient level (respectively Weighted κ 0.84, 95% CI 0.79-0.89 and 0.84, 95% CI 0.75-0.92). Intratumor heterogeneity between the cores per patient case was similar in both assays.

CONCLUSION

After validation a 22C3 LDT is non-inferior to the standardized 22C3 pharmDx assay and can be safely used to select HNSCC patients for pembrolizumab treatment.

Complete response to pembrolizumab in a patient with recurrent and metastatic urothelial bladder carcinoma reflecting coexisting sarcomatoid subtype and glandular differentiation: a case report

In advanced urothelial carcinoma (UC), approximately 20% of patients respond to pembrolizumab, an anti-programmed cell death-1 (PD-1) antibody. Herein, we reported a single case of UC showing coexistence of sarcomatoid subtype and glandular differentiation. Notably, only glandular differentiation was recurrent, probably progressive, and metastatic, which showed complete response to pembrolizumab. An 80-year-old woman presented with hematuria and dysuria, and an intra-vesical tumor was detected on ultrasound. Transurethral resections (TUR) were performed three times. In the first TUR, a sub-pedunculated tumor and a flat lesion were closely but independently located. Pathologically, the sub-pedunculated tumor was an invasive UC, sarcomatoid subtype. Meanwhile, the flat lesion was invasive UC with glandular differentiation. Despite the second and the additional TUR, the tumor was growing and a lymph node metastasis was detected. The third TUR specimen showed UC with glandular differentiation, and a positive PD-L1 expression as well as high density CD8-positive lymphocytic cells infiltration were observed. Pembrolizumab was administered for four courses after terminating the chemotherapy. The CT scan revealed shrinkage of both primary tumor and metastases. Cystectomy and lymph nodes dissection were performed, and no residual carcinoma was detected. The therapeutic effect was regarded as pathological complete response. Pembrolizumab could be effective for special subtype or divergent differentiation of UC, particularly in an event of an 'immune hot' tumor.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13691-022-00568-5.

Characterizing the Shifting Real-World Treatment Landscape by PD-L1 Testing Status and Expression Level in Advanced Non-Small Cell Lung Cancer

INTRODUCTION

Contemporary real-world data on advanced non-small cell lung cancer (aNSCLC) treatment patterns across programmed cell death-ligand 1 (PD-L1) expression levels and testing status are limited.

METHODS

A retrospective cohort was selected of adults newly diagnosed with aNSCLC between January 1, 2018, and July 31, 2021, who initiated first-line treatments, which were described by PD-L1 status and expression levels (≥ 50%, 1-49%, < 1%). Treatment received before and after PD-L1 test results were described for patients initiating first-line treatment before PD-L1 results. For patients who initiated chemotherapy alone before PD-L1 results, the probability of receiving immune checkpoint inhibitors (ICIs) after PD-L1 results was estimated by PD-L1 level and associated factors were explored.

RESULTS

Among 12,202 patients with aNSCLC initiating first-line treatment [54.7% male, mean (standard deviation) age 69.2 (9.4) years], the most common therapies were ICI-based regimens across PD-L1 levels, and chemotherapy alone among PD-L1-untested patients. Use of chemotherapy alone decreased between 2018 and 2019 and stabilized thereafter, accounting for 21-29% of first-line treatments across PD-L1 levels and 48% of untested patients in 2021. Of 1468 patients initiating first-line treatment before PD-L1 results, treatments remained unchanged in most patients after PD-L1 results. Among patients initiating chemotherapy alone before PD-L1 results, the probability of receiving ICIs within 45 days after test results was 40.5% [95% confidence interval (CI) 31.6-48.3%], 28.6% (95% CI 20.3-36.0%), and 22.9% (95% CI 16.9-28.4%) at PD-L1 ≥ 50%, 1-49%, and < 1%, respectively.

CONCLUSION

While ICI-based regimens accounted for most first-line treatments across PD-L1 levels, chemotherapy alone was initiated in > 20% of patients tested for PD-L1 and 48% of untested patients in 2021. Patients who initiated chemotherapy alone had a low probability of receiving ICIs after PD-L1 test results. These results highlight the need for understanding the role and timing of PD-L1 test results for informing treatment decisions for patients with aNSCLC.

Carboplatin and nab-paclitaxel chemotherapy with or without atezolizumab as front-line management for treatment-naïve metastatic nonsquamous non-small cell lung cancer with PD-L1 staining: a retrospective study

Purpose

The aim of this retrospective review was to compare the efficacy and safety of the atezolizumab plus carboplatin and nab-paclitaxel regimen versus the carboplatin and nab-paclitaxel regimen as front-line management for treatment-naïve, metastatic nonsquamous programmed death-ligand 1 (PD-L1)-positive non-small cell lung cancer (NSCLC) in a selected population.

Methods

Consecutive patients with untreated, metastatic nonsquamous PD-L1-positive NSCLC who initially received the atezolizumab plus carboplatin and nab-paclitaxel (ACN) regimen or carboplatin and nab-paclitaxel (CN) regimen were retrospectively identified in two medical institutions from 2017 to 2020. The co-primary end points were overall survival (OS) and progression-free survival (PFS); secondary end point was the rate of key adverse events (AEs).

Results

In sum, 171 patients were retrospectively analysed, 47 of whom were excluded according to the criteria used in this study, leaving 124 patients (ACN: n = 60, median age 64 years [range 46–75]; CN: n = 64, 63 years [47–72]). The median duration of follow-up was 27 months [range 1–37]. At the final follow-up, the median OS was 19.9 months (95% confidence interval [CI], 16.3–22.5) in the ACN group vs. 14.8 months (95% CI 12.5–17.2) in the CN group (hazard ratio [HR] 0.51, 95% CI 0.33–0.77; p = 0.001). A marked distinction in the median PFS was seen (8.5 months [95% CI 6.7–9.4] in the ACN group vs. in the CN group [5.1 months [95% CI 3.6–6.8; HR 0.60; 95% CI 0.38–0.95; p = 0.005]). The rates of the key AEs (neutropenia and anaemia) were greater in the ACN group than in the CN group (all p < 0.05), but these AEs were manageable.

Conclusion

Among selected populations of individuals with treatment-naïve, metastatic nonsquamous PD-L1-positive NSCLC, atezolizumab combined with carboplatin and nab-paclitaxel chemotherapy might have encouraging anticancer activity, with a tolerable safety profile.

Selectively down-regulated PD-L1 by albumin-phenformin nanoparticles mediated mitochondrial dysfunction to stimulate tumor-specific immunological response for enhanced mild-temperature photothermal efficacy

Background

Mild-temperature photothermal therapy (mild-PTT) has emerged as a highly promising antitumor strategy by triggering immunogenic cell death (ICD) to elicit both innate and adaptive immune responses for tumor control. However, mild-PTT still leads to the risk of tumor recurrence or metastasis because it could hardly completely eradicate tumors due to its impaired immunological efficacy owing to the enhanced PD-L1 expression in tumor cells after treatment.

Results

In this study, we described a hydrogen peroxide (H₂O₂) responsive manganese dioxide mineralized albumin nanocomposite loading with mitochondria function inhibitor phenformin (PM) and near-infrared photothermal dye indocyanine green (ICG) by modified two-step biomineralization method. In combination with ICG induced mild-PTT and PM mediated mitochondria dysfunction, PD-L1 expression was obviously down-regulated and the generated immunological responses was able to effectively attack the remaining tumor cells. Meanwhile, the risk of tumor metastasis was effectively inhibited by reducing the expression of tumor invasion-related signal molecules (TGF-β and vimentin) after combining treatment.

Conclusion

Such a strategy offers novel insight into the development of nanomedicine for mild-PTT as well as cancer immunotherapy, which can provide protection against tumor relapse post elimination of their initial and metastatic tumors.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01124-8.

Over-expression of PD-L1 after mild-photothermal therapy significantly limited its efficacy.

Phenformin could effectively downregulate PD-L1 expression and inhibit tumor metastasis through AMPK activation.

Hydrogen peroxide responsive manganese dioxide mineralized albumin nanocomplex co-loading with phenformin and ICG named ICG@PM@NP was constructed by modified two-step biomineralization method.

ICG@PM@NP could enhance T cell infiltration and antitumor metastasis in vivo.

ICG@PM@NP mediated mild-photothermal therapy could make up the defects of conventional mild-photothermal therapy in lacking the anti-metastasis ability and inducing enhanced PD-L1 expression.

Programmed cell death-ligand 1 (PD-L1)+ tumour cells and low-reacting programmed cell death 1 (PD1)+ tumour-infiltrating lymphocytes predict poor prognosis in Epstein-Barr virus+ diffuse large B-cell lymphoma

Epstein-Barr virus (EBV)⁺ diffuse large B-cell lymphoma (DLBCL) has specific tumour cell characteristics, and these patients have worse outcomes than EBV-negative DLBCL patients. We compared 38 EBV⁺ DLBCL patients with 43 methotrexate-associated EBV⁺ B-cell lymphoproliferative disorders (MTX⁺/EBV⁺ BLPDs) and 30 non-germinal centre (GC) subtype DLBCL. Lymphoma cells of the EBV⁺ DLBCL group were positive for BCL2 in 17 patients (44.7%), CMYC in 23 patients (60.5%), and p53 in 33 patients (86.8%), which was significantly higher than in the MTX⁺/EBV⁺ BLPD group (P < 0.05), and were positive for CD30 in 29 patients (76.3%), compared with two in non-GC subtype DLBCL (6.7%) (P < 0.0001). Significantly more EBV⁺ DLBCL patients (n = 16, 42.1%) had programmed cell death-ligand 1 (PD-L1)⁺ tumour cells than patients with non-GC subtype DLBCL (n = 5, 16.7%; P = 0.024), and PD-L1⁺ tumour cells were more common in advanced stages than in early stages (P = 0.048). Twenty-five EBV⁺ DLBCL patients (69.4%) had few reactive PD1⁺ tumour-infiltrating lymphocytes (TILs), compared with 12 patients with MTX⁺/EBV⁺ BLPDs (37.5%) (P = 0.008). In the EBV⁺ DLBCL group, CD30, BCL2, CMYC, and p53 expression was not related to patient prognosis. Poor outcomes were associated with PD-L1⁺ tumour cells (P = 0.001) and low-reacting PD1⁺ TILs (P = 0.02), while their combination conferred a worse outcome (P < 0.0001). Immune evasion by PD-L1⁺ tumour cells and exhaustion of PD1⁺ TILs may occur in EBV⁺ DLBCL patients, and PD-L1/PD1 interactions may influence tumour progression and poor prognosis.

Immune Cell Infiltration and the Expression of PD-1 and PD-L1 in Primary PDGFRA-Mutant Gastrointestinal Stromal Tumors

PURPOSE

To characterize the immune cell profile and expression of PD-1, PD-L1, and IDO in PDGFRA-mutant gastrointestinal stromal tumors (GISTs).

METHODS

The clinicopathological data of PDGFRA-mutant GIST patients who received surgical resection in Zhongshan Hospital between January 2013 and August 2019 were reviewed retrospectively. The specimens of tissue chips were detected for immune cell infiltration and the expression of PD-1, PD-L1, and IDO by immunohistochemical staining.

RESULTS

CD3⁺, CD8⁺, and CD68⁺ cells were the main infiltrating immune cells in the 42 patients included in this study. In addition, CD4⁺, CD56⁺, Foxp3⁺, and CD20⁺ cells were also observed. A higher CD8⁺ T cell count was associated with smaller tumor size and PDGFRA D842V mutation (P = 0.047, P = 0.005). A higher CD3⁺ and CD68⁺ cell count was associated with a higher mitotic index (P = 0.022, P = 0.006). CD4⁺ and CD20⁺ cell count was associated with tumor morphology (P = 0.002, P = 0.045). PD-1 expression was present in 37 (88%) samples. Eighteen samples were positive for PD-L1 expression, and it was higher in small vs. large tumors (P = 0.012) and epithelioid and mixed cell type vs. spindle cell type GISTs (P = 0.046). IDO expression was positive in all 42 patients. The number of CD4⁺ cells was significantly greater in the specimens with high IDO expression (P = 0.012).

CONCLUSION

There were abundant infiltrating immune cells in PDGFRA-mutant GISTs. PD-L1 expression was negatively associated with tumor size. The immunotherapy targeting PD-1/PD-L1 checkpoint and IDO may be valuable.

Programmed cell death-ligand 1 assessment in urothelial carcinoma: prospect and limitation

Programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) inhibition has revolutionized the treatment paradigm of urothelial carcinoma (UC). Several PD-L1 assays are conducted to formulate appropriate treatment decisions for PD-1/PD-L1 target therapy in UC. However, each assay has its own specific requirement of antibody clones, staining platforms, scoring algorithms, and cutoffs for the determination of PD-L1 status. These prove to be challenging constraints to pathology laboratories and pathologists. Thus, the present article comprehensively demonstrates the scoring algorithm used and differences observed in each assay (22C3, SP142, and SP263). Interestingly, the SP142 score algorithm considers only immune cells and not tumor cells (TCs). It remains controversial whether SP142 expressed only in TCs truly accounts for a negative PD-L1 case. Moreover, the scoring algorithm of each assay is complex and divergent, which can result in inter-observer heterogeneity. In this regard, the development of artificial intelligence for providing assistance to pathologists in obtaining more accurate and objective results has been actively researched. To facilitate efficiency of PD-L1 testing, several previous studies attempted to integrate and harmonize each assay in UC. The performance comparison of the various PD-L1 assays demonstrated in previous studies was encouraging, the exceptional concordance rate reported between 22C3 and SP263. Although these two assays may be used interchangeably, a clinically validated algorithm for each agent must be applied.

The Association of Tumor-Infiltrating Lymphocytes and Programmed Cell Death 1 Expression with the Incidence of Distant Metastasis in Triple-Negative Breast Cancer Subjects in Sanglah General Hospital, Bali, Indonesia

The triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with a high rate of distant metastasis. The tumor immunity microenvironment plays an important role, including tumor-infiltrating lymphocytes (TIL) and PD-1 (programmed cell death 1)/PD-L1 (programmed cell death-ligand 1), in promoting TNBC aggressiveness. This study aimed to determine the association of TIL and PD-L1 expression with the incidence of distant metastasis in TNBC. This study is a cross-sectional study involving TNBC subjects at Sanglah General Hospital, Denpasar, conducted in 2019. The parameters analyzed were the expression of TIL, PD-L1, and the incidence of distant metastasis. The expression of TIL was analyzed histopathologically while PD-L1 was measured with Ventana PD-L1 kit test. Subject characteristics were obtained from medical records. Data were collected and analyzed by SPSS 22.0. As many as 31 subjects with TNBC were included in this study, with 51.6% subjects with distant metastasis. The majority of subjects with distant metastasis had low TIL and low tumoral PD-L1 but high PD-L1 stromal in TIL. From statistical analysis, only PD-L1 stromal in TIL expression was associated significantly with distant metastasis (p = 0.043). In conclusion, there was a significant association between PD-L1 stromal in TIL and the incidence of distant metastasis in TNBC.

[Progress of PD-1/PD-L1 inhibitors in the treatment of small-cell lung cancer]

Small cell lung cancer (SCLC) is a neuroendocrine tumor, which accounts for about 15% of all lung cancers. SCLC is characterized by rapid growth and tendency to widespread metastasis at the initial stage. Although high response rates to first-line chemotherapy are observed, most patients relapse less than few months. In the past 5 years, some clinical trials found that the immune checkpoint inhibitors (ICIs) were effective in SCLC, especially programmed cell death 1/ligand 1 (PD-1/L1). Given this situation, the treatment patterns of SCLC have changed. This article briefly reviews the researches and studies of ICIs in the treatment of SCLC to provide reference to the clinicians.

Biphasic prognostic significance of PD-L1 expression status in patients with early- and locally advanced-stage non-small cell lung cancer

Programmed cell death-ligand 1 (PD-L1) expression on tumor cells is induced by interferon-gamma, suggesting the induction of an anti-tumor immune response. In turn, binding of PD-L1 to programmed cell death 1 (PD-1) triggers an immune checkpoint pathway that contributes to tumor growth. Though it remains to be elucidated, the clinical significance of PD-L1 expression might vary with tumor progression in non-small-cell lung cancer (NSCLC). Immunohistochemical analysis of PD-L1 was done in tumor specimens from patients who underwent radical surgery for stage I-IIIA NSCLC (n = 228). Tumor PD-L1 expression intensity was semi-quantitatively scored and its correlation with various clinicopathological features and postoperative relapse-free survival (RFS) was assessed relative to pathological stage. In stage I, postoperative RFS was significantly prolonged in patients with a high PD-L1 score compared with a low PD-L1 score, exhibiting 5-year relapse-free probabilities of 94.1% and 75.1%, respectively (P = 0.031). A multivariate analysis revealed that a high PD-L1 score was a prognostic factor of longer postoperative RFS (hazard ratio: 0.111, P = 0.033). Conversely, in stages II and IIIA, patients with a high PD-L1 score tended to suffer from postoperative tumor recurrence. In early-stage NSCLC, high tumor PD-L1 expression status represents a biomarker to predict good prognosis after radical surgery and may reflect the induction of an antitumor immune response. However, in locally advanced stage NSCLC, tumor PD-L1 expression status may reflect the execution of an immune checkpoint pathway and predicts the incidence of postoperative tumor recurrence.

[Present and Future of Efficacy Biomarkers in Immune Checkpoint Inhibitors of Small Cell Lung Cancer]

近年来，免疫治疗在小细胞肺癌领域取得了令人瞩目的突破，为患者带来生存获益。然而，现有的临床研究结果表明试验组通常在治疗开始3个月-6个月以后方可看出获益的趋势，因此如何筛选优势人群是免疫治疗研究的重点。目前已有的临床试验对生物标记物进行了不断地探索，但结果不尽一致。我们亟需有力可靠的疗效预测指标有效地筛选优势人群、扩大受益群体。故本文将对小细胞肺癌免疫治疗疗效预测指标的现状及未来的发展前进方向展开阐述。

RNA N6-methyladenosine demethylase FTO regulates PD-L1 expression in colon cancer cells

Fat mass and obesity-associated protein (FTO) is an enzyme that demethylates N6-methyladenosine (m⁶A), the most abundant RNA modifications in a cell. The upregulated expression of FTO promotes the progression of various types of cancer by modulating cell-intrinsic genes which relate to malignant potential. However, the impact of FTO on the expression of immune-checkpoint molecules in the tumor cells, which are important for immune escape, has not been well understood. We examined the relevance of FTO to programmed cell death-ligand 1 (PD-L1) expression in colon cancer cells. HCT-116 cells showed high expression of both FTO and PD-L1 proteins. The knockdown of FTO by small interfering RNA decreased mRNA and protein levels of PD-L1 in HCT-116 cells. To elucidate the underlying mechanism by which FTO regulates the expression of PD-L1, we depleted FTO in HCT-116 in the presence of IFN-γ, which is a major stimulus to upregulate PD-L1 expression. Depletion of FTO reduced PD-L1 expression in an IFN-γ signaling-independent manner. RNA immunoprecipitation assay revealed the m⁶A modification of the PD-L1 mRNA and the binding of FTO to the PD-L1 mRNA in HCT-116. Taken together, our results indicated that FTO could regulate PD-L1 expression in colon cancer cells and provides new insights into the regulation of PD-L1 expression by RNA modification.

Therapeutic effect of dual CAR-T targeting PDL1 and MUC16 antigens on ovarian cancer cells in mice

BACKGROUND

More favorable treatment against epithelial ovarian cancer (EOC) is urgently needed because of its insidious nature at an early stage and a low rate of five-year survival. The current primary treatment, extensive surgery combined with chemotherapy, exhibits limited benefits for improving prognosis. Chimeric antigen receptor T (CAR-T) cell technology as novel immunotherapy has made breakthrough progress in the treatment of hematologic malignancies, and there were also benefits shown in a partial solid tumor in previous research. Therefore, CAR-T cell technology may be a promising candidate as an immunotherapeutic tool against EOC. However, there are some weaknesses in targeting one antigen from the previous preclinical assay, such as on-target off-tumor cytotoxicity. The dual-target CAR-T cell may be a better choice.

METHODS

We constructed tandem PD1-antiMUC16 dual-CAR, PD1 single-CAR, and anti-MUC16 single-CAR fragments by PCR and genetic engineering, followed by preparing CAR-T cells via lentiviral infection. The expression of CAR molecules on single and dual CAR-T cells was detected by flow cytometry. The killing capacity and activation of CAR-T cells were measured by cytotoxic assays and cytokines release assays in vitro. The therapeutic capacity of CAR-T cells was assessed by tumor-bearing mice model assay in vivo.

RESULTS

We successfully constructed CARs lentiviral expression vectors and obtained single and dual CAR-T cells. CAR-T cells demonstrated robust killing capacity against OVCAR-3 cells in vitro. Meanwhile, CAR-T cells released plenty of cytokines such as interleukin-2(IL-2), interferon-γ (IFN-γ) and tumor necrosis factor-α(TNF-α). CAR-T cells showed a therapeutic benefit against OVCAR-3 tumor-bearing mice and significantly prolonged the survival time. Dual CAR-T cells were shown to be two to four times more efficacious than single CAR-T cells in terms of survival time.

CONCLUSION

Although exhibiting a similar ability as single CAR-T cells against OVCAR-3 cells in vitro, dual CAR-T cells demonstrated enhanced killing capacity against OVCAR-3 cells as compared to single CAR-T cells in vivo and significantly prolonged the survival time of tumor-bearing mice. PD1-antiMUC16 CAR-T cells showed more potent antitumor activity than single CAR-T cells in vivo. The present experimental data may support further research work that will have the potential to lead to clinical studies.

High PD-1 expression level is associated with an unfavorable prognosis in patients with cervical adenocarcinoma

Purpose

The effectiveness of immunotherapy for cervical adenocarcinoma (CA) has not been demonstrated yet. Programmed cell death 1 (PD-1), programmed cell death-ligand 1 (PD-L1), and CD8 may be used as biomarkers of response to immune therapy in CA patients. In the present study, we aimed to investigate whether the expression levels of PD-1, PD-L1, and CD8 can predict the prognosis of patients with CA and their response to immune checkpoint inhibition therapy.

Methods

In the present study, the clinical stage for all 82 patients with cervical adenocarcinoma was classified according to the guidelines of the International Federation of Gynecology and Obstetrics (FIGO); there were 5, 48, 5, 14, 8, and 2 patients with stage IA, IB, IIA, IIB, IIIB, and IVB disease, respectively. The levels of PD-1, PD-L1, and CD8 were analyzed by the immunohistochemical analysis of the formalin-fixed paraffin-embedded tumor samples. The correlation between the expression levels and patient prognosis was analyzed using the Kaplan–Meier method and univariate and multivariate Cox proportional hazard regression models.

Results

We observed a significant inverse correlation between the expression of PD-1 and CD8 (p = 0.001, chi-square test). We also found a significant inverse correlation between the expression of PD-L1 and CD8 (p = 0.027). The overall survival and progression-free survival rates were significantly worse in patients with positive PD-1 expression (p = 0.031; p = 0.087, respectively).

Conclusion

Our results suggest that a high PD-1 expression is associated with a poor prognosis in patients with CA. Further research is necessary to identify the molecular mechanisms that mediate this association.

Electronic supplementary material

The online version of this article (10.1007/s00404-020-05589-0) contains supplementary material, which is available to authorized users.

Clinicopathological Features of Programmed Cell Death-ligand 1 Expression in Patients with Oral Squamous Cell Carcinoma

Objective

Programmed cell death-ligand 1 (PD-L1) expression has been shown to play important roles in various types of cancer. However, the role of PD-L1 expression has not been conclusively reported in patients with oral squamous cell carcinoma (OSCC). Accordingly, in this meta-analysis, we investigated the clinicopathological value of PD-L1 expression in patients with OSCC.

Methods

Google Scholar, PubMed, EMBASE, and CNKI databases were searched to find relevant studies published through to September 16, 2019. The relationships between PD-L1 expression in patients with OSCC and clinicopathological features were assessed using risk ratio (RR) and 95% confidence intervals (CIs).

Results

Sixteen studies including 1989 participants were included. The results indicated that high PD-L1 expression was correlated with sex (RR = 1.28, 95% CI: 1.16-1.42, P < 0.001), N stage (RR = 1.19, 95% CI: 1.06-1.33, P = 0.003), M stage (RR = 1.64, 95% CI: 1.01-2.66, P = 0.044), low differentiation (RR = 1.16, 95% CI: 1.01-1.33, P = 0.034), and human papilloma virus infection (RR = 1.38, 95% CI: 1.14-1.68, P = 0.001), but unrelated to TNM stage or T stage. There was no significant publication bias in the studies included in this analysis.

Conclusions

This meta-analysis revealed that high PD-L1 expression in patients with OSCC was correlated with clinicopathological features. Further large-scale studies are necessary to confirm our results.

18F-FDG maximum standard uptake value predicts PD-L1 expression on tumor cells or tumor-infiltrating immune cells in non-small cell lung cancer

OBJECTIVES

Programmed cell death-ligand 1 (PD-L1) is expressed on tumor cells (TC) and tumor-infiltrating immune cells (IC). We conducted a retrospective study to investigate the relationship between PD-L1 expression on TC/IC and ¹⁸F-FDG uptake in patients with surgically resected non-small cell lung cancer (NSCLC).

METHODS

Total 362 NSCLC patients (297 adenocarcinoma and 65 squamous cell carcinoma) who underwent preoperative ¹⁸F-FDG-PET/CT imaging were analyzed retrospectively. Immunohistochemistry analysis was performed for PD-L1 expression on TC and IC in NSCLC specimens with 28-8 antibody. The cut-off value of 5% for defining PD-L1 positivity was determined according to previous trials. The association between PD-L1 expression and clinicopathological variables were analyzed, including age, gender, smoking status, tumor diameter, lymph node metastasis, stage and the maximum standardized uptake value (SUVmax).

RESULTS

PD-L1 positive expression was 50.8% (184/362) in NSCLC patients. Its positive expression on TC and IC were 24.3% (88/362) and 42.5% (154/362), respectively. SUVmax was significantly higher in patients with PD-L1 positive expression on TC or IC than that with negative. Multivariate analysis demonstrated that PD-L1 expression were correlated with SUVmax. The best cut-off value of SUVmax for PD-L1 expression on TC/IC was 8.5 [area under the curve (AUC) = 0.607, 95% CI 0.549-0.665, P = 0.001, sensitivity 50.5% and specificity 71.4%] determined by ROC curve.

CONCLUSION

High SUVmax is linked to PD-L1 expression on TC and IC in our patients with surgically resected non-small cell lung cancer. ¹⁸F-FDG-PET/CT imaging may be used to predict the PD-L1 expression on TC and IC in NSCLC patients.

Tumor immune response and immunotherapy in gastric cancer

Remarkable developments in immuno-oncology have changed the landscape of gastric cancer (GC) treatment. Because immunotherapy intervenes with tumor immune response rather than directly targeting tumor cells, it is important to develop a greater understanding of tumor immunity. This review paper summarizes the tumor immune reaction and immune escape mechanisms while focusing on the role of T cells and their co-inhibitory signals, such as the immune checkpoint molecules programmed death-1 and programmed deathligand 1 (PD-L1). This paper also describes past clinical trials of immunotherapy for patients with GC and details their clinical implications. Strong predictive markers are essential to improve response to immunotherapy. Microsatellite instability, Epstein-Barr virus, PD-L1 expression, and tumor mutational burden are now regarded as potent predictive markers for immunotherapy in patients with GC. Novel immunotherapy and combination therapy targeting new immune checkpoint molecules such as lymphocyte-activation gene 3, T cell immunoglobulin, and mucin domain containing-3, and indoleamine 2,3-dioxygenase have been suggested, and trials are ongoing to evaluate their safety and efficacy. Immunotherapy is an important treatment option for patients with GC and has great potential for improving patient outcome, and further research in immuno-oncology should be carried out.

Interobserver Reproducibility of PD-L1 Biomarker in Non-small Cell Lung Cancer: A Multi-Institutional Study by 27 Pathologists

Background

Assessment of programmed cell death-ligand 1 (PD-L1) immunohistochemical staining is used for treatment decisions in non-small cell lung cancer (NSCLC) regarding use of PD-L1/programmed cell death protein 1 (PD-1) immunotherapy. The reliability of the PD-L1 22C3 pharmDx assay is critical in guiding clinical practice. The Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists investigated the interobserver reproducibility of PD-L1 staining with 22C3 pharmDx in NSCLC samples.

Methods

Twenty-seven pathologists individually assessed the tumor proportion score (TPS) for 107 NSCLC samples. Each case was divided into three levels based on TPS: <1%, 1%–49%, and ≥50%.

Results

The intraclass correlation coefficient for TPS was 0.902±0.058. Weighted κ coefficient for 3-step assessment was 0.748±0.093. The κ coefficients for 1% and 50% cut-offs were 0.633 and 0.834, respectively. There was a significant association between interobserver reproducibility and experience (formal PD-L1 training, more experience for PD-L1 assessment, and longer practice duration on surgical pathology), histologic subtype, and specimen type.

Conclusions

Our results indicate that PD-L1 immunohistochemical staining provides a reproducible basis for decisions on anti–PD-1 therapy in NSCLC.

Clinical significance of PD-L1-positive cancer-associated fibroblasts in pN0M0 non-small cell lung cancer

OBJECTIVES

Cancer-associated fibroblasts (CAFs) are a dominant cell type in tumor stroma and support the generation of pro-tumorigenic microenvironment. CAFs have frequent opportunities to interact with immune cells infiltrating the tumor stroma, but the process remains to be determined. In this study, we focused on immune checkpoint mechanism. We also examined the induction of programmed cell death-ligand 1 (PD-L1) on CAFs by immune cell, and the clinical significance of PD-L1-expressed CAFs in non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

CAFs were isolated from human NSCLC tissues, and PD-L1 expression levels in CAFs were analyzed by real-time polymerase chain reaction and flow-cytometry. Following immunohistochemical analysis of PD-L1 in surgically resected pN0M0 NSCLC (n = 125, including 88 invasive adenocarcinomas and 37 squamous cell carcinomas), the correlation of PD-L1-positive CAFs with clinicopathological features was investigated.

RESULTS

PD-L1 mRNA and protein expression on CAFs was upregulated by exogenously supplemented interferon-gamma (IFN-γ) and downregulated through the depletion of IFN-γ. PD-L1 expression on CAFs was upregulated by co-culture with activated lymphocytes releasing IFN-γ. Immunohistochemistry revealed that PD-L1-positive CAFs were observed in 31 cases (24.8%). Postoperative relapse-free survival was significantly prolonged in patients with PD-L1-positive CAFs as compared with those with PD-L1-negative CAFs, with 5-year relapse-free probabilities of 84.5% and 66.3%, respectively (P = 0.031). Multivariate analysis revealed that PD-L1 expression on CAFs was an independent prognostic factor of longer relapse-free survival after surgery (hazard ratio: 3.225, P = 0.027).

CONCLUSION

PD-L1 expression on CAFs is reversibly regulated by environmental stimuli including IFN-γ from activated lymphocytes. In the non-metastatic NSCLC, PD-L1 expression on CAFs suggests the induction of anti-tumor immune responses, contributing to better prognosis after surgery.

First-line treatment for patients with advanced non-small cell lung carcinoma and high PD-L1 expression: pembrolizumab or pembrolizumab plus chemotherapy

Pembrolizumab monotherapy has become the preferred treatment for patients with advanced non-small cell lung carcinoma (NSCLC) and a programmed cell death-ligand 1 (PD-L1) tumor proportion score (TPS) of at least 50%. However, little is known about the value of adding chemotherapy to pembrolizumab in this setting. Therefore, we performed an indirect comparison for pembrolizumab plus chemotherapy versus pembrolizumab, using the frequentist methods. The primary outcomes were overall survival (OS), progression-free survival (PFS) and objective response rate (ORR). Data were retrieved from randomized trials comparing pembrolizumab plus chemotherapy or pembrolizumab monotherapy against chemotherapy. Five trials involving 1289 patients were included. Direct meta-analysis showed that both pembrolizumab plus chemotherapy (ORR: relative risk (RR) 2.16; PFS: hazard ratio (HR) 0.36; OS: HR 0.51) and pembrolizumab alone (ORR: RR 1.33; PFS: HR, 0.65; OS: HR 0.67) improved clinical outcomes compared with chemotherapy. Indirect comparison showed that pembrolizumab plus chemotherapy was superior to pembrolizumab alone, in terms of ORR (RR 1.62, 1.18–2.23) and PFS (HR 0.55, 0.32–0.97). A trend towards improved OS was also observed (HR 0.76, 0.51–1.14). In conclusion, the addition of chemotherapy to pembrolizumab further improves the outcomes of patients with advanced NSCLC and a PD-L1 TPS of at least 50%.

PD-L1 Testing in Non-small Cell Lung Cancer: Past, Present, and Future

Blockade of the programmed cell death-1 (PD-1) axis has already been established as an effective treatment of non-small cell lung cancer. Immunohistochemistry (IHC) for programmed death-ligand 1 (PD-L1) protein is the only available biomarker that can guide treatment with immune checkpoint inhibitors in non-small cell lung cancer. Because each PD-1/PD-L1 blockade was approved together with a specific PD-L1 IHC assay used in the clinical trials, pathologists have been challenged with performing various assays with a limited sample. To provide a more unified understanding of this, several cross-validation studies between platforms have been performed and showed consistent results. However, the interchangeability of assays may be limited in practice because of the risk of misclassification of patients for the treatment. Furthermore, several issues, including the temporal and spatial heterogeneity of PD-L1 expression in the tumor, and the potential for cytology specimens to be used as an alternative to tissue samples for PD-L1 testing, have still not been resolved. In the future, one of the main aims of immunotherapy research should be to find a novel predictive biomarker for PD-1 blockade therapy and a way to combine it with PD-L1 IHC and other tests.

Impact of EGFR mutation on the clinical efficacy of PD-1 inhibitors in patients with pulmonary adenocarcinoma

PURPOSE

We evaluated the predictive role of EGFR mutation on the efficacy of PD-1/PD-L1 inhibitor therapy in patients with advanced pulmonary adenocarcinoma while considering clinical factors such as PD-L1 expression, gender, and smoking status.

METHODS

Patients were required to have available data for EGFR mutation, PD-L1 expression, and efficacy of PD-1/PD-L1 inhibitors.

RESULTS

Among 178 patients with EGFR-mutant (n = 38) or wild-type (WT) (n = 140) tumors, the EGFR mutation group had a lower objective response rate (ORR) (15.8% vs. 32.9%, p = 0.04) than the EGFR WT group, similar to the pattern observed for other factors: weak/negative PD-L1 expression vs. strong PD-L1 expression (17.3% vs. 39.2%, p = 0.001); never smokers vs. smokers (19.4% vs. 35.1%, p = 0.03); and females vs. males (21.0% vs. 33.6%, p = 0.08). EGFR mutation and weak/negative PD-L1 expression were associated with a significantly shorter median PFS than EGFR WT (1.9 vs. 3.0 months, p = 0.04) and strong PD-L1 expression (1.6 vs. 3.9 months, p = 0.007), respectively. In multivariate analysis, EGFR mutation predicted worse ORR [hazard ratio (HR) 3.15; 95% confidence interval (CI) 1.15-8.63] and PFS (HR 1.75, 95% CI 1.11-2.75), as did weak/negative PD-L1 expression (ORR, HR 3.46, 95% CI 1.62-7.37; and PFS, HR 1.72, 95% CI 1.17-2.53).

CONCLUSIONS

Together with PD-L1 expression, EGFR mutation status is an important factor to predict the efficacy of PD-1/PD-L1 inhibitors in patients with pulmonary adenocarcinoma.

Tumour infiltrating lymphocytes and PD-L1 expression as potential predictors of outcome in patients with malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare and aggressive form of tumour. Some mesotheliomas have been proven to be highly immunogenic. Here, we investigated the correlation between tumour infiltrating lymphocytes (TILs) or programmed cell death ligand 1 (PD-L1) expression with overall survival (OS) in patients with MPM. 62 Paraffin-embedded formalin fixed (PEFF) samples were analysed for TILs and PD-L1 expression. Patients were divided in 4 groups according to a cut-off of the percentage of TILs found per sample as measured by immunohistichemistry: "0" or absent (between 0 and 5%), "1" or low (between 6 and 25%), "2" or moderate (between 26 and 50%) and "3" or high (between 51 and 75%). OS was then correlated with different TILs' expression patterns. Moreover, PD-L1 expression was assessed within the tumour as well as in the adjacent stroma on the same samples. Higher expression of peritumoral TILs (Group 2 + 3) versus Group 0 and 1 correlated with improved OS (p-value = 0.02). On the contrary PD-L1 expression seemed to be inversely correlated with clinical outcomes, even in the absence of statistical significance (HR 1.76; p = 0.083 95% IC 0.92-3.36 in areas within the tumour; HR 1.60; p = 0.176 95%; IC 0.80-3.19 in areas within the stroma). No relationship between TILs and PD-L1 expression was identified. Our research supports the use of TILs and PD-L1 expression as potential outcome predictors in patients with MPM. The use of TILs and PD-L1 as biomarkers for checkpoint inhibitors' efficacy warrants future investigation.

Human Leukocyte Antigen Class I and Programmed Death-Ligand 1 Coexpression Is an Independent Poor Prognostic Factor in Adenocarcinoma of the Lung

Background

Both human leukocyte antigen (HLA) class I and programmed death-ligand 1 (PD-L1) molecules are known to play important roles in cancer immunity. In this study, we evaluated HLA class I expression in resected adenocarcinoma of the lung, and investigated its prognostic impact in correlation with PD-L1 expression.

Methods

HLA class I and PD-L1 expression was evaluated by immunohistochemistry in a total of 403 resected lung adenocarcinomas using tissue microarray. Correlations between the expression of HLA class I/PD-L1 and clinicopathologic features and prognostic significance were analyzed.

Results

HLA class I expression was reduced in 91.6% of adenocarcinoma, and more frequently reduced in patients with younger age, absence of vascular invasion, and low pathologic stage (p = .033, p = .007, and p = .012, respectively). Positive PD-L1 expression in tumor cells was 16.1% (1% cut-off), and associated with poor differentiation, presence of vascular invasion and nodal metastasis (p < .001, p = .002, and p = .032, respectively). On survival analysis, HLA class I or PD-L1 expression alone did not show any statistical significance. On the integrated analysis, HLA class I (+)/PD-L1 (+) subgroup showed a significantly shorter overall survival than other groups (p = .001). Multivariate analysis revealed that coexpression of HLA class I and PD-L1 was an independent poor prognostic factor of lung adenocarcinoma. (p < .001; hazard ratio, 6.106; 95% confidence interval, 2.260 to 16.501).

Conclusions

Lung adenocarcinoma with coexpression of HLA class I and PD-L1 was associated with poor prognosis. This subgroup may evade immune attack by expressing PD-L1 protein despite HLA expression.

High PD-L1 expression correlates with primary resistance to EGFR-TKIs in treatment naïve advanced EGFR-mutant lung adenocarcinoma patients

OBJECTIVES

The main objective was to investigate the relationship between Programmed cell Death-ligand 1 (PD-L1) expression levels and the frequency of primary resistance to Epidermal Growth Factor Receptor (EGFR)-Tyrosine Kinase Inhibitor (TKI) in treatment naïve advanced EGFR-mutant lung adenocarcinoma patients.

MATERIALS AND METHODS

From 2012-2017, we enrolled advanced EGFR-mutant lung adenocarcinoma patients who displayed primary resistance to EGFR-TKI therapy, along with patients with disease control, and patients experiencing either stable disease or partial response to EGFR-TKI treatment.

RESULTS

Sixty-six patients were enrolled as the primary resistance group, while 57 patients were included as the disease control group. Fifteen-five (22.7%) patients had a PD-L1 Tumor Proportion Score (TPS) ≧50% in the primary resistance group, with only one patient (1.8%) having that score in the disease control group (P＜0.001). Twenty (30.3%) patients had a PD-L1 ≧25% in the primary resistance group, with 2 (3.5%) patients having that level in the disease control group (P＜0.001). Thirty (45.5%) patients had a PD-L1 ≧1% in the primary resistance group, with 7 (12.3%) patients at that level in the disease control group (P = 0.001). Patients with a PD-L1≧1% displayed a higher incidence of primary resistance to EGFR-TKIs than those with a PD-L1＜1% (Odds Ratio (OR), 5.95; 95% Confidence Interval (CI), 2.35-15.05; P＜0.001). The phenomenon existed still when the cutoff value was changed to both 25% (OR, 11.96; 95% CI, 2.65-53.87; P = 0.001) and 50% (OR, 16.47; 95% CI, 2.10-129.16; P = 0.008). The estimated median Progression-free Survival (PFS) rate was 7.3 months in patients with a PD-L1＜1%, 2.1 months in patients with a PD-L1≧1%, 1.8 months in patients with a PD-L1≧25%, and 1.6 months in patients with a PD-L1≧50%.

CONCLUSIONS

Treatment for advanced EGFR-mutant lung adenocarcinoma patients displaying a higher PD-L1 expression level experienced a higher frequency of primary resistance to EGFR-TKIs.

PD-L2 Expression as a Potential Predictive Biomarker for the Response to Anti-PD-1 Drugs in Patients with Non-small Cell Lung Cancer

BACKGROUND/AIM

To investigate the role of programmed cell death-ligand 2 (PD-L2) expression as a predictive biomarker for response to anti-programmed cell death-1 (PD-1) drugs in patients with non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Ten patients who had undergone curative lung resection and received the anti-PD-1 drugs for the recurrence were enrolled. The cut-off value for PD-L2 (antibody clone 176611) expression on tumor cells was set at 50%. Tumor response was evaluated according to immune-related response criteria.

RESULTS

Seven patients (70.0%) were positive for PD-L2. The response rates were 28.6% (2/7) and 33.3% (1/3) in patients with PD-L2-positive and PD-L2-negative NSCLC, respectively. Disease control was obtained in 2 patients despite the programmed cell death-ligand 1 (PD-L1)-negativity (antibody clone 22C3: 0%, antibody clone SP142: 0%), and these tumors expressed PD-L2 (≥1%).

CONCLUSION

PD-L2 expression may be a target of immunotherapy in patients with PD-L1-negative NSCLC.

Differences in PD-L1 expression on tumor and immune cells between lung metastases and corresponding primary tumors

BACKGROUND

It has been reported that the tumor microenvironment, including tumor-associated immune cells (ICs) and programmed cell death-ligand 1 (PD-L1) expression, differs between primary and metastatic tumors. This study aimed to elucidate the differences in PD-L1 expression on tumor cells (TCs) and ICs between lung metastases and corresponding primary tumors.

METHODS

We analyzed paired lesions from 44 patients diagnosed with lung metastases between 2005 and 2017 at Kyushu University. The percentages of PD-L1-positive TCs and ICs in lung metastases and the primary tumor were classified into five categories (0: <1%; 1: 1%-4%; 2: 5%-9%; 3: 10%-49%; and 4: ≥50%). Lesions in which ≥1% of the TCs and ICs were PD-L1-positive were considered positive.

RESULTS

The primary cancers included rectal (n = 19), colon (n = 10), liver (n = 10), bile duct (n = 2), stomach (n = 1), gall bladder (n = 1) and breast (n = 1). Discrepancies in PD-L1 expression on TCs and ICs between lung metastases and primary lesions were observed in 5 (11.4%, κ = 0.23) and 9 (20.5%, κ = 0.11) of the 44 cases, respectively. PD-L1 expression on ICs was higher in lung metastases than paired primary tumors (p = 0.026), although the percentage of PD-L1-positive TCs was not significantly different between lung metastases and primary tumors (p = 0.767).

CONCLUSIONS

There were significant differences in PD-L1 expression on TCs and ICs between lung metastases and primary tumors. Clinicians should be aware of these differences in the tumor microenvironment when treating patients with immunotherapy.

Detection of high PD-L1 expression in oral cancers by a novel monoclonal antibody L1Mab-4

Programmed cell death-ligand 1 (PD-L1), which is a ligand of programmed cell death-1 (PD-1), is a type I transmembrane glycoprotein that is expressed on antigen-presenting cells and several tumor cells, including melanoma and lung cancer cells. There is a strong correlation between human PD-L1 (hPD-L1) expression on tumor cells and negative prognosis in cancer patients. In this study, we produced a novel anti-hPD-L1 monoclonal antibody (mAb), L₁Mab-4 (IgG_2b, kappa), using cell-based immunization and screening (CBIS) method and investigated hPD-L1 expression in oral cancers. L₁Mab-4 reacted with oral cancer cell lines (Ca9-22, HO-1-u-1, SAS, HSC-2, HSC-3, and HSC-4) in flow cytometry and stained oral cancers in a membrane-staining pattern. L₁Mab-4 stained 106/150 (70.7%) of oral squamous cell carcinomas, indicating the very high sensitivity of L₁Mab-4. These results indicate that L₁Mab-4 could be useful for investigating the function of hPD-L1 in oral cancers.

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Programmed cell death-ligand 1 (PD-L1) is expressed in many cancers.

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PD-L1 expression has not been fully investigated in oral cancers.

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A novel anti-PD-L1 mAb L₁Mab-4 was developed in this study.

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L₁Mab-4 stained 70.7% of oral SCCs in a membrane-staining pattern.

Clinical Significance of PD-L1 Expression in Brain Metastases from Non-small Cell Lung Cancer

AIM

To investigate the association between positivity for programmed cell death-ligand 1 (PD-L1) in brain metastases (BM) and the prognosis or clinical factors in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Thirty-two patients with surgically resected brain-metastatic NSCLC were enrolled. The PD-L1 expression in BM was analyzed using the antibody against human PD-L1 (clone SP142). The PD-L1 positivity was defined as PD-L1 expression on brain-metastatic tumor cells of ≥5%.

RESULTS

Seven (21.9%) out of 32 patients showed PD-L1 positivity in BM. The PD-L1-positive BM group had a significantly shorter brain-specific disease-free survival than the PD-L1-negative BM group (p<0.05). PD-L1 positivity in BM was significantly associated with a heavy smoking history and the administration of radiotherapy for BM before surgery (p<0.05 and p<0.05, respectively).

CONCLUSION

The PD-L1 expression in BM from NSCLC may be associated with local recurrence following surgery, and the smoking- or radiotherapy-derived effects.

The Significance of the PD-L1 Expression in Non-Small-Cell Lung Cancer: Trenchant Double Swords as Predictive and Prognostic Markers

Lung cancer is the leading cause of death due to cancer worldwide. Surgery, chemotherapy, and radiotherapy have been the standard treatment for lung cancer, and targeted molecular therapy has greatly improved the clinical course of patients with non-small-cell lung cancer (NSCLC) harboring driver mutations, such as in epidermal growth factor receptor and anaplastic lymphoma kinase genes. Despite advances in such therapies, the prognosis of patients with NSCLC without driver oncogene mutations remains poor. Immunotherapy targeting programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) has recently been shown to improve the survival in advanced NSCLC. The PD-L1 expression on the surface of tumor cells has emerged as a potential biomarker for predicting responses to immunotherapy and prognosis after surgery in NSCLC. However, the utility of PD-L1 expression as a predictive and prognostic biomarker remains controversial because of the existence of various PD-L1 antibodies, scoring systems, and positivity cutoffs. In this review, we summarize the data from representative clinical trials of PD-1/PD-L1 immune checkpoint inhibitors in NSCLC and previous reports on the association between PD-L1 expression and clinical outcomes in patients with NSCLC. Furthermore, we discuss the future perspectives of immunotherapy and immune checkpoint factors.

Discrepancy in Programmed Cell Death-Ligand 1 Between Primary and Metastatic Non-small Cell Lung Cancer

AIM

To investigate the discordance in the programmed cell death-ligand 1 (PD-L1) expression between primary and metastatic tumors and analyze the association between the discordance and the clinical factors in non-small cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

Twenty-one NSCLC patients who underwent surgery or biopsy for paired primary and metastatic lesions at our Institution from 2005 to 2016 were analyzed. Lesions with the PD-L1 expression being ≥5% were considered PD-L1-positive.

RESULTS

The metastatic sites included the brain (n=16), adrenal gland (n=3), spleen (n=1) and jejunum (n=1). Negative conversion of the primary PD-L1-positive NSCLC and positive conversion of the primary PD-L1-negative NSCLC were observed in 3 (14%) and 2 (10%) cases, respectively. Radiotherapy for the metastatic brain lesion before its resection showed a significant relationship with the positive conversion of the primary PD-L1-negative NSCLC (p=0.048).

CONCLUSION

Radiotherapy-derived effects may contribute to the positive conversion of the primary PD-L1-negative NSCLC.

Prognostic value of programmed death-1, programmed death-ligand 1, programmed death-ligand 2 expression, and CD8(+) T cell density in primary tumors and metastatic lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma

BACKGROUND

Anti-programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) immunotherapy has been proved to be effective on gastric cancer in ongoing clinical trials. However, the value of PD-L1 in predicting responses of patients with gastric cancer to anti-PD-1/PD-L1 immunotherapy is controversial. Some studies suggested that intra- and inter-tumoral heterogeneity of PD-L1 expression might explain the controversy. This study aimed to analyze the expression of PD-L1, PD-L2, and PD-1 as well as CD8(+) T-cell density in primary tumors and lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma to explore the heterogeneity of PD-1 signaling pathway molecules.

METHODS

In primary tumors and metastatic as well as non-metastatic lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma, we detected PD-L1 and PD-L2 expression with immunohistochemistry. CD8(+) T-cell density in primary tumors and PD-1 expression on CD8(+) T cells were detected with immunofluorescence. Univariate analysis was used to determine the prognostic values of them. Cox proportional hazard regression model was used to identify independent risk factors that affect patients' overall survival and disease-free survival.

RESULTS

Among 119 eligible patients who had undergone surgical resection, the positive rate of PD-L1 was higher in metastatic lymph nodes than in primary tumors (45.4% vs. 38.7%, P = 0.005); the positive rate of PD-1 on CD8(+) T cells was significantly higher in primary tumors and metastatic lymph nodes than in tumor-free lymph nodes (both P < 0.001). The intensity of PD-1 expression on CD8(+) T cells in primary tumors and in metastatic lymph nodes were stronger than that in tumor-free lymph nodes from the same patient. Beside, the positive rate of PD-L2 did not show any differences between primary tumors and metastatic lymph nodes. In multivariate analysis, PD-L1 expression, PD-L2 expression, a low density of CD8(+) T cells in primary tumors, and PD-1 expression on CD8(+) T cells in primary tumors were associated with poor prognosis.

CONCLUSION

The expression of PD-L1 is heterogeneous in primary tumors and in metastatic lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma, which might explain the inconsistent results in assessing the prognostic value of PD-L1 expression in previous studies.

Combination Therapy of Radiotherapy and Anti-PD-1/PD-L1 Treatment in Non-Small-cell Lung Cancer: A Mini-review

Immune checkpoint inhibitors against programmed cell death-1 (PD-1) or programmed cell death-ligand 1 (PD-L1) are a standard pharmacologic therapy for patients with non-small-cell lung cancer (NSCLC). Substantial data have accumulated in recent years showing that radiotherapy combined with immunotherapy is more effective than monotherapy alone. Preclinical studies have shown that PD-L1 expression is upregulated on tumor cells after radiotherapy, resulting in the synergistically enhanced antitumor effect of irradiation and PD-L1 blockade. In the clinical setting, patients receiving radiotherapy before anti-PD-1 treatment have had a significantly better prognosis than those who have not undergone radiotherapy. In the present report, we reviewed previous studies of the combination of radiotherapy and anti-PD-1/PD-L1 treatment for NSCLC. In addition, we report our case of a patient whose PD-L1 expression gradually increased in brain metastases from NSCLC after repeated radiotherapy. In the perspectives portion, we focused on the questions of how to integrate radiotherapy into anti-PD-1/PD-L1 agent regimens and described several ongoing clinical trials.

PD-L1 over-expression is associated with a poor prognosis in Asian non-small cell lung cancer patients

BACKGROUND

The prognostic role of programmed cell death-ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC) remains controversial. This meta-analysis was conducted to clarify the association of PD-L1 with survival in NSCLC patients.

METHODS

Relevant studies were collected from PubMed, Embase and Web of Science. Only studies in which PD-L1 expression was detected by immunohistochemical staining in NSCLC patients correlated with patient survival data were included. Stata 12.0 was performed in this meta-analysis.

RESULTS

Fifteen studies with 3116 patients were included in this meta-analysis. The combined hazard ratio (HR) of 1.18 (95%CI, 0.90-1.56; P>0.05) shows that PD-L1 over-expression in NSCLC patients didn't associate with overall survival (OS). However, subgroup analysis indicated that PD-L1 over-expression was correlated with poor OS in Asian patients (HR=1.84, 95%CI: 1.14-2.28; P<0.001). Moreover, the results suggested that a significant relationship between PD-L1 expression and OS was also showed in studies with late stage (HR=1.27, 95%CI: 1.06-1.48; P=0.031), poor tumor differentiation (HR=1.86, 95%CI: 1.35-2.64; P=0.001) and anaplastic lymphoma kinase (ALK) translocation (HR=2.58, 95%CI: 1.03-5.78; P=0.028).

CONCLUSIONS

PD-L1 over-expression is correlated with a poor prognosis in Asian NSCLC patients.

Scoring of PD-L1 expression intensity on pulmonary adenocarcinomas and the correlations with clinicopathological factors

Introduction

The contribution of programmed cell death ligand-1 (PD-L1) immune checkpoint molecule toward progression of non-small cell lung cancer (NSCLC) has not yet been elucidated, in part, because of lack of a standardised method to evaluate PD-L1 expression. In this study, we developed a novel method for the evaluation of PD-L1 expression on NSCLC cells and examined its correlation with clinicopathological characteristics.

Methods

After immunohistochemical examination of PD-L1 expression for surgically resected pulmonary adenocarcinomas (n=106), based on the findings that PD-L1 are consistently expressed on alveolar macrophages, PD-L1 staining intensity of tumour cells was classified into four levels relative to PD-L1 staining intensity in alveolar macrophages; PD-L1 expression scores (range, 0–300) were semiquantitatively assessed. An analysis of statistical association between PD-L1 expression score and clinicopathological characteristics was performed.

Results

Almost all of the alveolar macrophages in the specimens were moderately to strongly stained with PD-L1, serving as an internal positive control in the immunohistochemistry of PD-L1. PD-L1 expression score (median, 52.3) was significantly higher in tumours with G2/3 differentiation than in those with G1 (p=0.022) and higher in those with lymphatic invasion than in those without invasion (p=0.032). Postoperative relapse-free survival was significantly shorter in patients with a high PD-L1 expression score than in those with low PD-L1 expression score (p=0.035). Smoking habits, histological subtype, and epidermal growth factor receptor mutation status were not associated with PD-L1 expression score.

Conclusions

Given the heterogeneous distribution of PD-L1 expression in pulmonary adenocarcinoma cells, the scoring of PD-L1 expression on tumour cells relative to that in alveolar macrophages appears to be a valid indicator of PD-L1 status of patients with pulmonary adenocarcinomas, demonstrating a significant correlation with several factors associated with tumour progression.

The prognostic value of PD-L1 expression for non-small cell lung cancer patients: a meta-analysis

BACKGROUND

A meta-analysis was conducted to investigate the much-debated relationship between the gene expression of programmed cell death-ligand 1 (PD-L1) and cancer patient prognosis. The prognostic value of measuring PD-L1 expression in non-small cell lung cancer (NSCLC) patients was analyzed.

METHODS

We searched PubMed for studies about the relationship between PD-L1 expression and NSCLC patient prognosis. Only studies with patient survival data related to PD-L1 expression in NSCLC patients with different characteristics were included. The effect size (ES) for this analysis was the hazard ratio (HR) with 95% confidence intervals (CI) for overall survival (OS).

RESULTS

Six studies with 1157 patients were included with the defined including and excluding criteria. There is no significant heterogeneity among the studies (I(2) = 0%, p = 0.683). PD-L1 expression was significantly associated with the differentiation of tumor (poor vs. well: OR = 1.91, 95% CI: 1.33-2.75, p = 0.001). High PD-L1 expression was also correlated with poor prognosis in terms of the OS of patients with NSCLC (pooled HR = 1.75, 95% CI: 140-2.20, p < 0.001; heterogeneity test: I(2) = 0%, p = 0.643).

CONCLUSIONS

NSCLC patients with positive PD-L1 expression exhibited poor OS. The PD-L1 expression was higher in tumors with poor differentiation.