Positive PD-L1 Expression Research Articles

Spectrum of Gastric Carcinoma in a Tertiary Care Centre with Special Reference to PDL1 and Cyciln D1

Introduction: Gastric carcinoma is the fifth most frequently diagnosed tumor and the fourth leading cause of death. They represent a heterogenous group of tumors with multifactorial etiologies, both environmental and genetic. PD-L1 is a transmembrane protein, and a positive PD-L1 expression in gastric carcinoma may be a predictive biomarker of the response to PD-1/PD-L1 immune checkpoint inhibitors. Cyclin D1 is an important cell cycle regulatory protein and involved in the carcinogenesis of various cancers including gastric cancer. Aims: The aim of this study is to find out the clinicopathological spectrum of gastric carcinoma and to show the immunohistochemical expression of Cyclin D1 and PD-L1 to evaluate their prognostic importance and their therapeutic impact. Study Design: It is an observational cross-sectional study conducted in the Department of Pathology in collaboration with the Department of Surgery, in a tertiary care hospital. Partial and total gastrectomies were selected from January 2021 to July 2022 in a tertiary care hospital. Clinical history was collected in the study proforma. Immunohistochemical staining for Cyclin D1 and PD-L1 was performed. Material and Methods: The clinicopathological parameters like age, gender, histological type, regional lymph node status, lymphovascular invasion, perineural invasion, and pathological stage were compared and correlated with Cyclin D1 and PD-L1 expression. Results: Positive Cyclin D1 and PDL1 expression were found in 50% and 70% cases of gastric carcinoma, respectively. Cyclin D1 expression showed statistically significant correlation with anemia, regional lymph node status, and lymphovascular invasion. PD-L1 and Cyclin D1 expression showed statistically significant association between them (p value-0.0006). Conclusion: Cyclin D1 and PDL1 are important biomarkers in gastric carcinoma. Their contribution towards prediction of progression and prognosis, along with newer therapeutic modalities, is of immense importace in these patients. A statistically significant correlation was found between these two markers.

Brief Report: Prognostic impact of adjuvant immunotherapy in patients with resectable non-small cell lung cancer following neoadjuvant chemoimmunotherapy

ObjectiveThe potential survival benefits of adjuvant immunotherapy for resectable non-small cell lung cancer (NSCLC) following neoadjuvant chemoimmunotherapy, as well as the optimal number of adjuvant immunotherapy cycles, remain uncertain. This study aims to evaluate the prognostic impact of adjuvant immunotherapy and determine the optimal number of cycles. MethodsA total of 438 patients who received neoadjuvant chemoimmunotherapy between August 2019 and June 2022 across four hospitals were enrolled in this study, with a median follow-up time of 31.3 months. Recurrence-free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier methods and tested by log-rank test. Unstratified Cox proportional hazards models were fitted to the subgroups. ResultsIn this multi-center cohort, 29.7% of patients (n=130) achieved a pathologic complete response (pCR). Patients who received adjuvant immunotherapy experienced significant survival benefits compared to those who did not (RFS: hazard ratio [HR] 0.63, 95% confidence interval [CI] 0.41-0.98, P = 0.037; OS: HR 0.27, 95% CI 0.13-0.57, P < 0.001). Subgroup analyses showed that patients with a squamous histologic type, positive PD-L1 expression, and those with a major pathologic response (MPR) particularly benefited from adjuvant immunotherapy. Additionally, we found that six cycles of adjuvant immunotherapy served as a threshold for better prognostic differentiation, suggesting that six or more cycles may be more beneficial. ConclusionsOur study demonstrated that the addition of adjuvant immunotherapy to neoadjuvant chemoimmunotherapy is significantly associated with improved RFS and OS in patients with resectable NSCLC. We also identified that six cycles of adjuvant immunotherapy may be the optimal regimen for these patients.

Can multiplexing Immunohistochemistry for PD-L1, CD68, and CD3 improve scoring for “Keytruda®” Indication?

Abstract Introduction/Objective FDA-approved companion diagnostics immunohistochemistry scoring for PD-L1 is essential for Keytruda ® treatment in patients with NSCLC. The challenge with PD-L1 testing alone is false positive PD-L1 expression score due to alveolar macrophage infiltration. Multiplexing with PD-L1, CD68, and CD3 could help alleviate this issue. By viewing PD-L1 expression on tumor cells, CD68 expression on macrophages, and the presence of CD3+ T cells on a single slide, pathologists will be able to see the presence of an immune microenvironment (high PD-L1 expression with abundant macrophages) and the potential for response to other types of Immunotherapies (presence of T cells). Methods/Case Report Positive NSCLC FFPE blocks were sectioned and stained using Agilent Dako Omnis. Two combinations of multiplex staining were prepared for each block by staining PD-L1 (brown) alone first followed by CD3 and CD68. First slide: CD3(Vina Green), CD68(Magenta); Second slide: CD3(Magenta), CD68(Vina Green). To prevent wash out, dehydration and clearing occurred with two changes of 100% alcohol and three changes of xylene for manual cover slipping. Results (if a Case Study enter NA) Manual scoring of PD-L1 alone vs two different multiplex combinations was compared to Agilent Proscia digital AI scoring using a preliminary study set (9 positives, 2 negatives). CD68-green and CD3-magenta showed better discrimination than CD68-magenta and CD3-green at a glance. This could be due to the staining intensity and nonspecific background staining of CD68-magenta. Manual scoring was higher compared to digital scoring, which could be due to the human error of positive bias. Digital scoring was significantly lower for PD-L1 alone vs both multiplex stains. The digital scoring for the multiplex stains showed a higher scoring percentage by removing false positive macrophages. Conclusion Reflex scoring workflow is being developed to focus on difficult cases using the multiplex triple stain, i.e. clear negative and clear &amp;gt;50% with 3+ intensity. More cases will be collected and studied to further investigate the improved PD-L1 scoring with digital imaging assisted by artificial intelligence and to compare the multiplex color combinations.

Real-world effectiveness and safety of recombinant human endostatin plus PD-1 inhibitors and chemotherapy as first-line treatment for EGFR/ALK-negative, advanced or metastatic non-small cell lung cancer

BackgroundThis study aimed to evaluate the effectiveness and safety of recombinant human endostatin (Rh-endostatin) plus programmed cell death 1 (PD-1) inhibitors and chemotherapy as first-line treatment for advanced or metastatic non-small cell lung cancer (NSCLC) in a real-world setting.MethodsThis was a retrospective study on patients with EGFR/ALK-negative, advanced or metastatic NSCLC. Patients received Rh-endostatin plus PD-1 inhibitors and chemotherapy every three weeks for 4 to 6 cycles. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety.ResultsA total of 68 patients were included in this retrospective analysis. As of data cutoff (December 13, 2022), the median follow-up of 21.4 months (interquartile range [IQR], 8.3-44.4 months). The median PFS and OS was 22.0 (95% confidence interval [CI]: 16.6-27.4) and 31.0 months (95% CI: 23.4-not evaluable [NE]), respectively. The ORR was 72.06% (95% CI: 59.85-82.27%), and DCR was 95.59% (95% CI: 87.64-99.08%). Patients with stage IIIB/IIIC NSCLC had significantly longer median PFS (23.4 vs. 13.2 months), longer median OS (not reached vs. 18.0 months), and higher ORR (89.2% vs. 51.6%) than those with stage IV NSCLC (all p ≤ 0.001). The ORR was higher in patients with high PD-L1 expression (tumor proportion score [TPS] ≥ 50%) than in those with low PD-L1 expression or positive PD-L1 expression (75% vs. 50%, p = 0.025). All patients experienced treatment-related adverse events (TRAEs), and ≥ grade 3 TRAEs occurred in 16 (23.53%) patients.ConclusionsRh-endostatin combined with PD-1 inhibitors plus chemotherapy as first-line treatment yielded favorable effectiveness with a manageable profile in patients with advanced or metastatic NSCLC, representing a promising treatment modality.

PD-L1 and B7-H3 are Effective Prognostic Factors and Potential Therapeutic Targets for High-Risk Thyroid Cancer.

The prognosis of thyroid cancer in patients varies significantly based on different pathological types or distinct clinical situations. Investigating the expression of immune checkpoint molecules PD-L1 and B7-H3 in high-risk thyroid cancer and their correlation with clinicopathological features and prognosis will contribute to the development of novel therapeutic strategies. A retrospective sample of 202 patients with thyroid cancer who underwent surgery at the Cancer Hospital of the Chinese Academy of Medical Sciences was collected, including 33 cases of anaplastic thyroid cancer (ATC), 21 cases of differentiated thyroid cancer (DTC) with distant metastasis (DM), 7 cases of differentiated high-grade thyroid carcinoma (DHGTC), and 109 cases of aggressive subtypes of papillary thyroid carcinoma (PTC) (including 28 cases of tall cell PTC, 31 cases of diffuse sclerosing PTC, 20 cases of solid PTC, 15 cases of columnar cell PTC, and 15 cases of hobnail PTC). In the control group, there were 32 cases of classic PTC. The differences in protein expression between PD-L1 and B7-H3 in several high-risk thyroid cancers and normal tissues and controls were compared by immunohistochemical staining, and the clinicopathological features and prognostic relevance were statistically analyzed. The expression of PD-L1 in ATC (P < 0.001), tall cell PTC (P = 0.031), and DHGTC (P = 0.003) was significantly higher than that in classic PTC. The expression of B7-H3 in ATC (P < 0.001), DTC with DM (P = 0.001), diffuse sclerosing PTC (P = 0.013), columnar cell PTC (P = 0.007), solid PTC (P < 0.001), hobnail PTC (P < 0.001), and DHGTC (P < 0.001) was significantly higher than that in classic PTC. In ATC, PD-L1 expression correlated significantly with extrathyroidal extension (ETE) (P = 0.027) and B7-H3 expression correlated significantly with male patients (P = 0.031) and lymph node metastasis (LNM) (P = 0.026). The positive expression of B7-H3 (P = 0.041) was an independent risk factor for disease progression in ATC. B7-H3 positive expression (P = 0.049), PD-L1 positive expression (P = 0.015), and tumor diameter ≥ 2cm (P = 0.038) were independent risk factors for disease progression in patients with DTC with DM. PD-L1 positive expression (P = 0.019) and tumor diameter ≥ 2cm (P = 0.018) were independent risk factors for disease progression in patients with aggressive subtypes of PTC. B7-H3 and PD-L1 are expected to be effective prognostic indicators for patients with aggressive thyroid cancer, which can help in optimization of individualized treatment strategies. Immunotherapy targeting these two molecules may provide new and complementary ideas for the treatment of high-risk/refractory thyroid cancer.

Optimizing first-line TKI treatment efficacy in PD-L1-positive EGFR-mutated NSCLC: the impact of antiangiogenic agents.

In individuals receiving treatment with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), those exhibiting positive PD-L1 expression might experience reduced progression-free survival (PFS). However, the effects on overall survival (OS) and the determination of efficacious treatment approaches are still not well-defined. In our retrospective study, we examined data from 193 NSCLC patients with advanced EGFR mutations who received first-line TKI treatments, treated at two centers of Shaw Hospital in Zhejiang, China. This analysis covered a period from 1 January 2016 to 30 April 2023. Patients with PD-L1 positivity exhibited a markedly shorter average PFS (9.5months versus 17.8months, P < 0.001) and OS (44.4months versus 65.7months, P = 0.016) relative to those without PD-L1 expression. This difference in both PFS and OS remained statistically significant even after adjusting for multiple factors (P < 0.001 for PFS and P = 0.028 for OS). In the PD-L1-positive cohort, introducing combination antiangiogenic significantly extended both PFS (from 9.1 to 25.7months, P = 0.026) and OS (from 42 to 53.5months, P = 0.03). Post-first-line TKI therapy, 39.3% of PD-L1-positive patients and 54.5% of PD-L1-negative patients developed the T790M mutation (P = 0.212), with no notable difference in PFS from second-line TKI treatments between the groups. Additionally, subsequent combination therapy with immunotherapy markedly prolonged OS in the PD-L1-positive group. However, for PD-L1-negative patients, neither combination antiangiogenic therapy nor later-line immunotherapy demonstrated significant benefits in PFS or OS. For PD-L1-positive patients, combined antiangiogenic treatments and immunotherapy can significantly improve survival outcomes. In contrast, PD-L1-negative patients show less benefit from these therapies, highlighting the greater efficacy of these treatments in PD-L1-positive individuals.

Immunotherapy and PD-L1 Tumor Expression in Moroccan Non-Small Cell Lung Cancer Patients with Various Metastasis.

The question of whether tumor expression of PD-L1 and the presence of distant metastasis could influence the efficacy of immunotherapy represents a major challenge and needs to be further elucidated. The aim of this study is to evaluate the predictive significance of tumor expression of PD-L1 as well as the number and site of metastasis in non-small cell lung cancer (NSCLC) among Moroccan patients treated with immunotherapy. Between January 2019 and February 2023, we recruited Moroccan patients with metastatic NSCLC. All were treated with immunotherapy, either as monotherapy or in combination with chemotherapy. Immunohistochemistry was used to assess PD-L1 (clone 22C3) and ALK (clone D5F3) status. EGFR status was established by qPCR. Tumor PD-L1 expression was classified into 2 levels: TPS <1% (negative expression) and TPS ≥1% (positive expression). Statistical analysis was performed using SPSS Statistics V.21 software. The median age of patients (N=40) was 67 years (39- 92 years) and the sex ratio was 9. Disease dissemination revealed that 22.5% (N=9) of patients had a metastatic burden ≥ 3 (MB≥3). As for the sites of metastasis, the results showed that 20% (N=8), 10% (N=4), 42.5% (N=17), 22.5% (N=9), 27.5% (N=11), 45% (N=18) and 27.5% (N=11) of patients had developed lymph node, liver, bone, brain, pleural, contralateral lung and adrenal metastasis respectively. Positive PD-L1 expression was significantly associated with shorter overall survival (OS = 17.19 vs. 28.85 months, p=0.01). High metastatic burden (MB ≥ 3) was associated with lower objective response rate (ORR), shorter progression-free survival (PFS), and reduced OS, respectively (ORR = 0 vs. 58.06%, p=0.002; PFS = 10.23 vs. 25.27 months, p=0.001; and OS = 11.60 vs. 27.91 months, p=0.003). Only the presence of osseous metastasis was significantly associated with lower ORR, shorter PFS, and OS compared to other metastatic locations (ORR = 5.88 vs. 73.9%, p=0.000; PFS = 10.72 vs. 31.33 months, p=0.000; and OS = 11.39 vs. 36.17 months, p=0.000). Finally, the presence of hepatic metastasis was significantly associated with shorter PFS (10.75 months) compared to those without hepatic metastasis (22.53 months) (p=0.046). Finally, the results of the multivariate analysis revealed that the presence of bone metastasis was strongly correlated with a significant decrease in progression-free survival (p=0.001) as well as overall survival (p=0.002). Our results suggest that tumor expression of PD-L1 and metastatic burden should play a significant role in predicting the response to immunotherapy. Furthermore, it is important to note that the presence of osseous and hepatic metastasis could negatively influence the clinical outcomes of immunotherapy.

What's new in gastric cancer?

In the locally advanced stage, multimodal therapies such as perioperative chemotherapy with FLOT or neoadjuvant radiochemotherapy are recommended. The integration of immunotherapy into these concepts could improve the prognosis. Phase II/III trials such as DANTE, KEYNOTE-585 and MATTERHORN show promising results in terms of pathological remissions but data on survival time extension for unselected patients are so far sobering. Immunotherapies and new targeted therapies offer hope in the palliative treatment of metastatic gastric cancer. Studies such as CheckMate-649 and KEYNOTE-859 show an improvement in survival and response rates. Currently, both pembrolizumab and nivolumab have been approved for the first-line treatment of tumors with positive PD-L1 expression. In HER2-positive tumors, the KEYNOTE-811 study showed that patients benefit from combination therapies with immune checkpoint inhibition and anti-HER2 therapies. The antibody-drug conjugate trastuzumab-deruxtecan is a promising second-line treatment option for HER2-positive tumors after treatment failure with trastuzumab.In addition, the bispecific antibody zanidatamab shows promising results in first-line treatment. New targeted therapies against CLDN18.2 and FGFR2b are showing promising results. The anti-claudin 18.2 (CLDN18.2) antibody zolbetuximab leads to improved survival compared to chemotherapy alone in patients with CLDN18.2 positive disease in first-line therapy, with approval expected in 2024.

PD-L1 expression in ovarian clear cell carcinoma using the 22C3 pharmDx assay

BackgroundOvarian clear cell carcinoma (OCCC), well known for its chemoresistance to platinum-based chemotherapy, exhibited a good response in clinical trials of anti–PD-1/PD-L1 inhibitors. By assessing PD-L1 expression, we sought to determine the potential therapeutic benefit of PD-1/PD-L1 inhibitors in OCCC.Methods and resultsThe retrospective study included 152 individuals with OCCC between 2019 and 2022 at Peking Union Medical College Hospital. Paired tumors of primary versus recurrent lesions (17 pairs from 15 patients) or primary versus metastatic lesions (11 pairs from 9 patients) were also included. The 22C3 pharmDx assay and whole sections were used for PD-L1 immunohistochemical staining. Pathologists with experience in premarket clinical trials evaluated PD-L1 expression based on various diagnostic criteria (TPS 1%, CPS 1, or CPS 10). The number and percentage of positive PD-L1 cases were 34 (22.4%, TPS ≥ 1%) and 59 (38.8%, CPS ≥ 1), respectively. Thirty-three (21.7%) of the cases had high PD-L1 expression (CPS ≥ 10). Half of the platinum-resistant patients (11/22) were PD-L1 positive (CPS ≥ 1). In addition, positive PD-L1 expression (CPS ≥ 1) was related to clinicopathological characteristics that represented a worse prognosis, such as advanced stages, lymph node metastasis, and distant metastasis (p = 0.032, p < 0.001 and p = 0.003, separately). PD-L1 was expressed equally or more in the recurrent lesion compared with its matched primary lesion.ConclusionsIn conclusion, anti–PD-1/PD-L1 inhibitors are a promising therapeutic choice for OCCC. For evaluation of PD-L1 expression, CPS is more recommended than TPS. Evaluation of recurrent lesion was still suitable and predictive when the primary tumor tissue was not available. Distant metastatic lesions can serve as alternative samples for PD-L1 evaluation, while usage of lymphatic metastatic lesions is not recommended.

A retrospective analysis of efficacy and safety of lenvatinib combined with PD-1 inhibitor and chemotherapy in advanced biliary tract cancer (BTC).

e16173 Background: Lenvatinib combined with PD-1 inhibitor and chemotherapy has showed a relatively high antitumor activity for ICC in phase 2 clinical trials. This study retrospectively analyzes the efficacy and safety of real-world lenvatinib combined with PD-1 inhibitor and chemotherapy in BTC. Methods: Patients with advanced BTC who received lenvatinib combined with PD-1 inhibitor plus oxaliplatin and gemcitabine (Gemox) chemotherapy were retrospectively screened. The overall survival, progression-free survival, objective response rate, disease control rate and safety were evaluated. Results: From Jan 2021 to Apr 2023, 27 pathologically-confirmed advanced BTC pts were enrolled. The median age is 61 (range, 39-74) years, 18 (66.7%) were male. Fourteen patients had TNM stage Ⅳdisease, and 7 patients had stage III. Twenty-six (96.3%) patients had an ECOG performance status of 1. All patients were child-pugh A. Fourteen patients had metastasis, 8 patients with lymph node metastasis, 4 with bone metastasis. 11 (40.7%) had positive PD-L1 expression. At baseline, 18 (66.7%) patients had a CA19-9 level &gt; 200 U/mL. The median CEA level was 3.56 ng/mL; 48.1% of the patients had a level &gt; 5 ng/mL. At the date cut off (Dec 15, 2023), the median follow-up time was 10.4 months (range: 4.8-25.7). ORR was 70.4% (19/27), and disease control rate (DCR) was 85.2% (23/27). Three pts with locally advanced disease were down-staged and then underwent resection. They remained disease-free survival at the end of last follow-up. The median PFS was 9.0 months (95% CI: 4.0-14.0) and median duration of response (DOR) was 9.8 months. The median OS was 20.4 months (95% CI: 13.6-27.2). 12-months OS rate was 73.3% (95% CI: 57.5%-89.2%).20/27 pts experienced treatment-related adverse events (AE). No grade 5 AE was observed. The most common AE was fatigue 66.7% (18/27), headache 7.4% (2/27). Grade 3 fatigue and grade 3 kidney injury occurred in 1 patient separately. Conclusions: Lenvatinib combined with PD-1 inhibitor and Gemox chemotherapy provided remarkable efficacy with reasonable tolerability in advanced BTC patients.

Detection and surveillance of circulating tumor cells in sarcoma for predicting therapy response and prognosis.

e23573 Background: Generally sarcomas are categorized as soft tissue and bone sarcomas and represent heterogenous group of malignancies with more than 70 distinct histologic subtypes. Due to their rarity and heterogeneity, sarcomas present particular challenges for accurate diagnosis, prognosis, and treatment. The presence and persistence of circulating tumor cells (CTCs) in the peripheral blood are believed to be associated with poor prognosis and distant metastases. A blood-based CTCs test is thus greatly needed for monitoring disease progression and predicting clinical outcomes. Methods: In this study, we developed a CTCs test for the detection and surveillance of sarcoma patients’ CTCs, and subsequently explored its clinical value. 123 patients with sarcomas were enrolled as the cohort for serial CTCs tests. Dynamic CTCs counting, in combination with therapy evaluation and post-treatment follow-up, was used to explore predicting pre- and post-chemotherapy evaluation and prognosis. Results: Quantification of CTCs demonstrated a significant increase in sarcoma patients compared to healthy individuals. Furthermore, patients in stage III-IV had a higher CTC count than those in stage I-II (p&lt;0.01), suggesting a correlation between CTCs and disease development. Remarkably, there was variation in the quantity of CTCs among different types of sarcomas. The highest number of CTCs was observed in undifferentiated small round cell sarcoma, followed by soft tissue tumor, while bone tumors had the lowest number. In addition, the number of CTCs in patients with positive PD-L1 expression was considerably greater than in those with negative expression (p&lt;0.01). The count of CTCs shown a substantial decrease following neoadjuvant chemotherapy treatment. There was a decline in the number of CTCs both before and after postoperative adjuvant chemotherapy treatment, however, there was no significant statistical discrepancy. The number of CTCs at the baseline was shown to be considerably larger in the group of patients with progressive disease or stable disease (PD+SD) compared to the group with partial response or complete response (PR+CR) (p&lt;0.05). This difference was particularly pronounced for interstitial-type CTCs (p&lt;0.01). Conclusions: The rate of presence of CTCs in the peripheral blood of sarcoma patients is high, and patients with an increased percentage of CTCs after treatment have a poor treatment effect. The dynamic monitoring of changes in CTCs counts after treatment has clinical significance for the timely detection of recurrence or metastasis. CTCs also showed a clinical value in prediction of therapy efficiency or prognosis, and may be clinically valuable for the whole course management of patients.

Tifcemalimab combined with toripalimab and chemotherapy as 1st line treatment for extensive-stage small cell lung cancer (ES-SCLC): A phase Ib/II, open-label study.

8089 Background: Tifcemalimab, a humanized IgG4 monoclonal antibody against B and T lymphocyte attenuator (BTLA), has shown preliminary anti-tumor activities in combination with toripalimab (anti-PD-1) as a later line treatment for patients with extensive-stage small cell lung cancer (ES-SCLC). We further conducted a multi-cohort phase Ib/II study (NCT05664971) to evaluate the safety and efficacy of tifcemalimab combined with toripalimab and chemotherapy as a 1st line treatment for patients with advanced lung cancer. Here, we report the preliminary results from the ES-SCLC cohort. Methods: Patients without previous systemic anti-tumor therapy for ES-SCLC were eligible. Patients received tifcemalimab 200mg in combination with toripalimab 240mg and standard chemotherapy (etoposide + carboplatin/cisplatin) intravenously once every three weeks (Q3W) for 4 cycles, then followed by tifcemalimab plus toripalimab maintenance therapy until disease progression, intolerable toxicity, or completion of 2 years treatment. Primary endpoints included safety and objective response rate (ORR) by investigators per RECIST v1.1. Results: From 7/12/2023 to 12/6/2023, a total of 44 ES-SCLC patients were enrolled. As of Dec 28, 2023, the median follow-up duration was 8.3 weeks. The median age of the patients was 65.5 (range 48-73) years, and 84.1% (37/44) were males. Forty-one (93.2%) patients experienced treatment-emergent adverse events (TEAEs), and 26 (59.1%) experienced ≥ grade 3 TEAEs. The most common TEAEs included leukopenia (65.9%), neutropenia (63.6%), anemia (40.9%) and thrombocytopenia (40.9%). No treatment-related adverse events led to discontinuation of tifcemalimab and toripalimab. Four (9.1%) patients experienced immune related AE (irAEs), and 1 experienced ≥ grade 3 irAE. Among 37 evaluable patients, 32 PR and 5 SD were observed. The ORR was 86.5% (32/37) and the DCR was 100% (37/37). By the data cut-off date, 94.6% of the responses were ongoing and the median duration of response was not reached. The preliminary biomarker analysis of tumor tissue suggested 100% ORR was observed among patients with either PD-L1 or HVEM positive expression. Further biomarker analysis will be updated. Conclusions: Tifcemalimab in combination with toripalimab and chemotherapy showed a promising objective response rate with a manageable safety profile as a 1st line treatment for patients with ES-SCLC. Continued follow-up is ongoing for additional safety and efficacy (PFS and OS) evaluation after extended exposure. Clinical trial information: NCT05664971 .

Investigation of RBM10 mutation and its associations with clinical and molecular characteristics in EGFR-mutant and EGFR-wildtype lung adenocarcinoma

BackgroundRBM10 is commonly mutated in lung adenocarcinoma (LUAD). However, its role in the pathogenesis of LUAD remains undefined. EGFR-mutant LUAD represents a distinct subset of non-small cell lung cancer (NSCLC). The function of RBM10 in tumor pathogenesis is supposed to differ between EGFR-mutant and EGFR-wt LUAD. This study aimed to interrogate the prevalence of RBM10 mutation in a large cohort of Chinese patients with LUAD and investigate the association of RBM10 mutation with clinical and molecular characteristics of EGFR-mutant and EGFR-wt LUAD. MethodsTumor sequencing data from 2848 Chinese patients with LUAD were retrospectively reviewed and analyzed. The prevalence of RBM10 was also compared with other three cohorts: OrigMed (n = 1222), MSKCC (n = 1267), and TCGA (n = 566). The associations of RBM10 mutation with clinical and molecular characteristics were assessed. An external cohort of 182 patients with LUAD who received PD-1 inhibitor were used to investigate the association of RBM10 mutation with clinical outcomes upon immunotherapy. ResultsOur cohort showed a higher prevalence of RBM10 in EGFR-mutant LUAD than in EGFR-wt LUAD (14.8 % vs. 6.5 %, p < 0.001). The enrichment of RBM10 mutations in EGFR-mutant LUAD was also seen in another Chinese cohort (OrigMed: 14.9 % vs. 7.8 %, p < 0.001), but not in the two western cohorts (MSKCC: 7.4 % vs. 9.5 %, p = 0.272; TCGA: 8.1 % vs. 6.7 %, p = 0.624). RBM10 mutations co-occurred more frequently with EGFR L858R mutations (23.7 %) than with other types of EGFR mutations (19 del: 7.7 %; other: 7.1 % in others, p < 0.001). In EGFR-mutant LUAD, RBM10 mutations were more commonly found in stage I (18.2 %) and II (21.8 %) vs. stage III (9.4 %) and IV (11.3 %) tumors (p < 0.001). The proportion of PD-L1 positive expression in EGFR-mutant LUAD with concomitant RBM10 mutation was not different from that those without RBM10 mutations (41.8 % vs. 47.9 %, p = 0.566). In contrast, RBM10 mutation occurred more frequently in EGFR-wt LUAD at stage II-IV (stage II: 12.0 %, stage III: 8.7 %, stage IV: 6.6 %) than at stage I (2.8 %). EGFR-wt LUAD with concomitant RBM10 mutations had higher proportions of PD-L1 expression positivity (78.9 % vs. 61.9 %, p = 0.014) and higher tumor mutational load (8.97 vs. 2.99 muts/Mb, p < 0.001) than those without. Patients with EGFR-wt LUAD who also harbored RBM10 loss of function (LOF) mutations had a longer median PFS upon immunotherapy than those with RBM10 non-LOF mutations (7.15 m vs. 2.60 m, HR = 4.83 [1.30–17.94], p = 0.010). ConclusionWe comprehensively investigated RBM10 mutations in a Chinese cohort with LUAD. Compared to western cohorts, a significant enrichment of RBM10 mutations in EGFR-mutant LUAD compared to EGFR-wildtype LUAD in the Chinese population. RBM10 mutation shows different associations with clinical and molecular characteristics between EGFR-mutant and EGFR-wt LUAD, suggesting a divergent mechanism between these two subsets via which RBM10 deficiency contribute to tumor pathogenesis. The findings contribute to our understanding of the molecular landscape of LUAD and highlight the importance of considering population-specific factors in cancer genomics research.

MIIP downregulates PD-L1 expression through HDAC6 in cutaneous melanoma

PurposeImmune checkpoint inhibitors have improved the objective response rate and survival of melanoma patients. However, there are still many melanoma patients suffering from disease progression due to primary or secondary immune checkpoint inhibitor resistance, as is observed in the failure of anti-PD1/PD-L1 therapy. While the expression of valuable markers, such as TMB, MSI, and PD-L1, could serve as effective predictors of anti-checkpoint inhibitor therapies, tumor cell PD-L1 expression and its regulating mechanism would significantly affect the anti-PD-1 immunotherapy response and efficacy. Therefore, it is urgent to determine the function of PD-1/PD-L1 expression in melanoma and its associated pathways to enhance the efficacy of anti-PD-1 therapies.MethodsA cohort of 133 patients with histologically confirmed melanoma from Tianjin Medical University Cancer Institute & Hospital were included in this study. We performed immunohistochemical staining to detect the expression of Migration and invasion inhibitory protein (MIIP), HDAC6 and PD-L1. Kaplan–Meier and log-rank test were used for survival analysis. As for vitro, Western blot was used in melanoma cell lines to verify the signaling pathway that MIIP regulates PD-L1 expression.ResultsMIIP expression was decreased in melanoma and that the negative expression of MIIP was correlated with worse overall survival. The positive expression of HDAC6, a molecule that is downstream of MIIP, had a positive trend with decreased overall survival. At the same time, the positive expression of PD-L1, a crucial costimulatory molecule, was associated with decreased overall survival. Furthermore, there was a positive association between HDAC6 and PD-L1 protein expression (p < 0.01), and this correlation is more prominent in cutaneous melanoma than acral melanoma. In cutaneous melanoma cell lines, we found that increasing MIIP led to decreased HDAC6, pSTAT3, and PD-L1 expression. Knocking down MIIP led to increased HDAC6, pSTAT3, and PD-L1 expression. Combining the published results, showing that HDAC6 can regulate PD-L1 expression through STAT3, our present data suggest that MIIP inhibits the expression of PD-L1 by downregulating HDAC6 in melanoma. Most importantly, methods for targeting MIIP-HDAC6-PD-L1 pathways, such as treatment with HDAC6 inhibitors, might indicate a new therapeutic approach for enhancing immune checkpoint inhibitor therapies in melanoma.ConclusionsOur findings highlight the immunomodulatory effects of MIIP in the inhibition of PD-L1 expression by downregulating HDAC6 in melanoma. Methods for targeting MIIP-HDAC6-PD-L1 pathways might be new therapeutic approaches for enhancing immune checkpoint inhibitor therapies in melanoma.

Prognostic and Clinical Significance of PD-L1, EGFR and Androgen Receptor (AR) Expression in Triple-Negative Breast Cancer (TNBC) Patients.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and is associated with high recurrence rates, a high incidence of distant metastases and poor overall survival. The aim of this study was to investigate the role of PD-L1, EGFR and AR expression in TNBC promotion and progression. To that end, we analyzed the immunohistochemical expression of these genes in 125 TNBC patients and their relation to clinicopathological parameters and survival. An elevated expression of PD-L1 was significantly correlated with higher tumor and nuclear grade, while a low expression was correlated with loco-regional recurrence without any influence on survival. Contrary to this, the expression of AR showed a positive impact on the DFI and a negative association with tumor grade. Furthermore, PD-L1 and AR demonstrated simultaneous expression, and further co-expression analysis revealed that a positive expression of PD-L1/AR notably correlates with tumor and nuclear grade and has a significant impact on a longer DFI and OS, while a negative PD-L1/AR expression is significantly associated with metastases. Therefore, our results suggest that positive PD-L1/AR expression is beneficial for TNBC patients. In addition, an elevated expression of EGFR contributes to metastases and a worse DFI and OS. In conclusion, we think that low PD-L1/low AR/high EGFR expression followed by high Ki67 expression constitutes a 'high risk' profile of TNBC.

Evaluation of PD-L1 Expression in Colorectal Carcinomas by Comparing Scoring Methods and Their Significance in Relation to Clinicopathologic Parameters.

This study aims to evaluate PD-L1 expression in colorectal carcinomas (CRCs) by using the tumor proportion score (TPS) and the combined positive score (CPS), and to investigate whether there is a correlation with clinicopathologic features. A cross-sectional study was conducted that included samples from patients with colorectal adenocarcinoma treated with colon resection and rectal resection after neoadjuvant radio- and chemotherapy at the Department of Abdominal Surgery at Požega Hospital in the period from 2017 to 2022. The study included 102 tumor tissue samples from patients after resection and the pathohistological diagnosis of adenocarcinoma. In our study, the PD-L1 positivity rate after the TPS was 42 (41%) samples, and after the CPS, 97 (95%) of them (p < 0.001). The positive expression of PD-L1 in tumor cells using the TPS method showed a statistically significant association with adenocarcinoma (TPS ≥ 10-50% and ≥50%). There were significantly more that were moderately differentiated, with TPS ≥ 50%, and those poorly differentiated had values ≥ 10-50%. There were significantly more patients with a status of more than one positive lymph node with TPS values ≥ 10-50%. Patients without metastases in the lymph nodes are significantly more likely to have CPS values > 50%, compared with other lymph node statuses. These results suggest that the total number of PD-L1-expressing cells, including tumor and immune cells, is a more sensitive biomarker than the number of PD-L1-expressing tumor cells alone in CRC.

Abstract PO1-24-11: Distinct patterns of MHC class I, PD-L1 expression, and T-cell infiltration in different subtypes of ductal carcinoma in situ of the breast

Abstract Background: Ductal carcinoma in situ (DCIS) of the breast encompasses various subtypes with distinct behaviors. Immune cell infiltration within the tumor microenvironment is thought to influence DCIS progression. Tumor-infiltrating lymphocytes (TILs) serve as a surrogate marker for the adaptive immune response. The interaction between programmed death 1 (PD-1) and its ligand PD-L1 suppresses effector T-cell function. Major histocompatibility complex (MHC) class I molecules play a critical role in presenting tumor antigens to cytotoxic T cells. Despite the significance of PD-L1 and MHC class I in immune evasion, limited data exist on their correlation with T-cell infiltration in DCIS subtypes. Methods: Using immunohistochemistry, we examined MHC class I and PD-L1 expression, along with CD3+ and CD8+ T lymphocytes, in 131 DCIS cases through tissue microarrays. DCIS subtypes included hormone receptor-positive (HR+)/human epidermal growth factor 2-negative (HER2-), HR+/HER2+, HR-/HER2+, and triple-negative (TN) subtypes. Results: Among the 128 interpretable cases, the distribution was as follows: HR+/HER2- (50.8%), HR+/HER2+ (14.1%), HR-/HER2+ (26.5%), and TN (8.6%). HER2+ subtypes (HR+/HER2+ and HR-/HER2+) exhibited higher stromal TILs, CD3+ T cells, and CD8+ T cells compared to HR+/HER2- subtype. MHC class I loss was observed in 16.4% (21/128) of cases, with the highest frequency in the HR+/HER2- subtype (29.2%), followed by HR-/HER2+ (5.9%), HR+/HER2+ (0%), and TN (0%) subtypes. DCIS cases lacking MHC class I expression displayed lower stromal CD8+ T cell infiltration than those with intact MHC class I. PD-L1 expression in immune cells (≥1%) was detected in 18.8% (24/128) of cases and correlated with increased stromal TILs, CD3+ T cells, and CD8+ T cells. PD-L1 expression was more prevalent in HER2+ subtypes than in HR+/HER2- subtype. PD-L1-positive DCIS cases mostly retained MHC class I expression (95.8%), except for one case (4.2%) in the HR-/HER2+ subtype. The highest numbers of stromal CD3+ and CD8+ T cells were observed in DCIS cases with intact MHC class I and positive PD-L1 expression. The correlation between MHC class I and PD-L1 expression and infiltration of CD3+ and CD8+ T cells was maintained in HR+/HER2- and HR-/HER2+ subtypes. Notably, tumoral CD3+ and CD8+ T cells showed no significant association with MHC class I or PD-L1 expression. Furthermore, MHC class I and PD-L1 expression did not predict tumor recurrence. Conclusion: We observed distinct patterns of MHC class I and PD-L1 expression and T-cell infiltration among DCIS subtypes. Enhancing our understanding of MHC class I, PD-L1, and immune subsets, including CD8+ T cells, may contribute to the development of immune modulating therapies for DCIS, particularly in the HER2+ subtype. Citation Format: Nah Ihm Kim, Min Ho Park, Ji Shin Lee. Distinct patterns of MHC class I, PD-L1 expression, and T-cell infiltration in different subtypes of ductal carcinoma in situ of the breast [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-24-11.

Immune checkpoint markers and tumour mutation burden in Wilms tumour: a study of 59 cases

Wilms tumour (WT) is the most common renal tumour in children, and studies of immune checkpoint inhibitors (ICIs) treatment and markers are limited in number. In this study we investigated the ICIs' related immune landscape by examining the expression of PD-L1, PD-1, CD8 and DNA mismatch repair (MMR) proteins by immunohistochemistry (IHC), tumour mutation burden (TMB), and correlations with histology and clinical outcome. Positive PD-L1 (SP263) expression was defined as modified combined positive score (CPS) ≥1. A total of 59 WTs (from 2000 to 2017), including eight (14.0%) with anaplasia, from 46 patients were analysed (45 primary and 14 metastatic). Thirteen WTs (13/59, 22%) were positive for PD-L1 (8 primary, 5 metastatic; CPS 1.11-3.42). Positive PD-L1 expression was associated with diffuse anaplasia (p<0.05) and significantly shorter progression-free survival (p<0.05) among WTs with favourable histology (n=39). CD8+ lymphocytes were present in all analysed WTs. A subset of CD8+ cells co-expressed PD-1, which was associated with favourable histology and treatment. MMR IHC stains identified two (2/18, 11%) WTs with isolated PMS2 loss. All six WTs analysed for TMB showed low mutation burden. We found CD8+ lymphocytes in all analysed WTs and identified a fraction of WT (17.8% of primary and 35.8% of metastatic) with positive PD-L1 CPS, suggesting potential response to ICIs in some patients.

Comprehensive genomic profiling of pulmonary spindle cell carcinoma using tissue and plasma samples: insights from a real-world cohort analysis.

Pulmonary spindle cell carcinoma (PSCC) is a rare and aggressive non-small cell lung cancer (NSCLC) subtype with a dismal prognosis. The molecular characteristics of PSCC are largely unknown due to its rarity, which limits the diagnosis and treatment of this historically poorly characterized malignancy. We present comprehensive genomic profiling results of baseline tumor samples from 22 patients histologically diagnosed with PSCC, representing the largest cohort to date. Somatic genetic variant detection was compared between paired plasma samples and primary tumors from 13 patients within our cohort. The associations among genomic features, treatment, and prognosis were also analyzed in representative patient cases. TP53 (54.5%), TERT (36.4%), CDKN2A (27.3%), and MET (22.7%) were most frequently mutated. Notably, 81.8% of patients had actionable targets in their baseline tumors, including MET (22.7%), ERBB2 (13.6%), EGFR (9.1%), KRAS (9.1%), ALK (9.1%), and ROS1 (4.5%). The median tumor mutation burden (TMB) for PSCC tumors was 5.5 mutations per megabase (muts/Mb). TMB-high tumors (>10 muts/Mb) exhibited a significantly higher mutation frequency in genes such as KRAS, ARID2, FOXL2, and LRP1B, as well as within the DNA mismatch repair pathway. The detection rates for single nucleotide variants and structural variants were comparable between matched tumor and plasma samples, with 48.6% of genetic variants being mutually identified in both sample types. Additionally, a patient with a high mutation load and positive PD-L1 expression demonstrated a 7-month survival benefit from chemoimmunotherapy. Furthermore, a patient with an ALK-rearranged tumor achieved a remarkable 3-year progression-free survival following crizotinib treatment. Overall, our findings deepen the understanding of the complex genomic landscape of PSCC, revealing actionable targets amenable to tailored treatment of this poorly characterized malignancy.

SMARCA4 Mutations in Gastroesophageal Adenocarcinoma: An Observational Study via a Next-Generation Sequencing Panel.

The clinical impact of SMARCA4 mutations (SMARCA4ms) in gastroesophageal adenocarcinoma (GEA) remains underexplored. This study aimed to examine the association of SMARCA4ms with clinical outcomes and co-occurrence with other gene mutations identified through a next-generation sequencing (NGS) panel in GEA patients. A total of 256 patients with metastatic or recurrent GEA who underwent NGS panel profiling at the MD Anderson Cancer Center between 2016 and 2022 were included. Comparative analyses were performed to assess clinical outcomes related to SMARCA4ms. The frequency and types of SMARCA4ms and their co-occurrence with other gene mutations were also examined. SMARCA4ms were identified in 19 patients (7.4%). These SMARCA4ms were significantly associated with non-signet ring cell subtype (p = 0.044) and PD-L1 positive expression (p = 0.046). No difference in survival between the SMARCA4m and SMARCA4-normal group was observed (p = 0.84). There were significant associations between SMARCA4ms and FANCA, IGF1R, KRAS, FANCL, and PTEN alterations. Notably, 15 of the 19 SMARCA4m cases involved SNV missense mutations, with frequent co-occurrences noted with TP53, KRAS, ARID1A, and ERBB2 mutations. These results serve as the first comprehensive examination of the relationship between SMARCA4ms and clinical outcomes in GEA.