Changes in tumour expression of programmed death-ligand 1 after neoadjuvant concurrent chemoradiotherapy in patients with squamous oesophageal cancer

Recent developments in immunotherapy for gastrointestinal tract cancers

The past few decades have witnessed the rise of immunotherapy for Gastrointestinal (GI) tract cancers. The role of immune checkpoint inhibitors (ICIs), particularly programmed death protein 1 (PD-1) and PD ligand-1 antibodies, has become increasingly pivotal in the treatment of advanced and perioperative GI tract cancers. Currently, anti-PD-1 plus chemotherapy is considered as first-line regimen for unselected advanced gastric/gastroesophageal junction adenocarcinoma (G/GEJC), mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal cancer (CRC), and advanced esophageal cancer (EC). In addition, the encouraging performance of claudin18.2-redirected chimeric antigen receptor T-cell (CAR-T) therapy in later-line GI tract cancers brings new hope for cell therapy in solid tumour treatment. Nevertheless, immunotherapy for GI tumour remains yet precise, and researchers are dedicated to further maximising and optimising the efficacy. This review summarises the important research, latest progress, and future directions of immunotherapy for GI tract cancers including EC, G/GEJC, and CRC.

Correlation of PD-L1 expression with CD8+ T cells and oxidative stress-related molecules NRF2 and NQO1 in esophageal squamous cell carcinoma

Oxidative stress and the immune microenvironment both contribute to the pathogenesis of esophageal squamous cell carcinoma (ESCC). However, their interrelationships remain poorly understood. We aimed to examine the status of key molecules involved in oxidative stress and the immune microenvironment, as well as their relationships with each other and with clinicopathological features and prognosis in ESCC. The expression of programmed death-ligand 1 (PD-L1), CD8, nuclear factor erythroid-2 related factor-2 (NRF2), and NAD(P)H quinone oxidoreductase 1 (NQO1) was detected using immunohistochemistry in tissue samples from 176 patients with ESCC. We employed both combined positive score (CPS) and tumor proportion score (TPS) to evaluate PD-L1 expression and found a positive correlation between CPS and TPS. Notably, PD-L1 expression, as assessed by either CPS or TPS, was positively correlated with both NRF2 nuclear score and NQO1 score in stage II-IV ESCC. We also observed a positive correlation between the density of CD8+ T cells and PD-L1 expression. Furthermore, high levels of PD-L1 CPS, but not TPS, were associated with advanced TNM stage and lymph node metastases. Moreover, both PD-L1 CPS and the nuclear expression of NRF2 were found to be predictive of shorter overall survival in stage II-IV ESCC. By using the Mandard-tumor regression grading (TRG) system to evaluate the pathological response of tumors to neoadjuvant chemotherapy (NACT), we found that the TRG-5 group had higher NRF2 nuclear score, PD-L1 CPS, and TPS in pre-NACT biopsy samples compared with the TRG-3 + 4 group. The NQO1 scores of post-NACT surgical specimens were significantly higher in the TRG-5 group than in the TRG 3 + 4 group. In conclusion, the expression of PD-L1 is associated with aberrant NRF2 signaling pathway, advanced TNM stage, lymph node metastases, and unfavorable prognosis. The dysregulation of PD-L1 and aberrant activation of the NRF2 signaling pathway are implicated in resistance to NACT. Our findings shed light on the complex interrelationships between oxidative stress and the immune microenvironment in ESCC, which may have implications for personalized therapies and improved patient outcomes.

Immune cell patterns before and after neoadjuvant immune checkpoint blockade combined with chemoradiotherapy in locally advanced esophageal squamous cell carcinoma

BACKGROUND

Neoadjuvant immune checkpoint blockade (ICB) combined with chemoradiotherapy offers high pathologic complete response (pCR) rate for patients with locally advanced esophageal squamous cell carcinomas (ESCC). But the dynamic tumor immune microenvironment modulated by such neoadjuvant therapy remains unclear.

PATIENTS AND METHODS

A total of 41 patients with locally advanced ESCC were recruited. All patients received neoadjuvant toripalimab combined with concurrent chemoradiotherapy. Matched pre- and post-treatment tissues were obtained for fluorescent multiplex immunohistochemistry (mIHC) and IHC analyses. The densities and spatial distributions of immune cells were determined by HALO modules. The differences of immune cell patterns before and after neoadjuvant treatment were investigated.

RESULTS

In the pre-treatment tissues, more stromal CD3 + FoxP3 + Tregs and CD86+/CD163 + macrophages were observed in patients with residual tumor existed in the resected lymph nodes (pN1), compared with patients with pCR. The majority of macrophages were distributed in close proximity to tumor nest in pN1 patients. In the post-treatment tissues, pCR patients had less CD86 + cell infiltration, whereas higher CD86 + cell density was significantly associated with higher tumor regression grades (TRG) in non-pCR patients. When comparing the paired pre- and post-treatment samples, heterogeneous therapy-associated immune cell patterns were found. Upon to the treatment, CD3 + T lymphocytes were slightly increased in pCR patients, but markedly decreased in non-pCR patients. In contrast, a noticeable increase and a less obvious decrease of CD86 + cell infiltration were respectively depicted in non-pCR and pCR patients. Furthermore, opposite trends of the treatment-induced alterations of CD8 + and CD15 + cell infiltrations were observed between pN0 and pN1 patients.

CONCLUSIONS

Collectively, our data demonstrate a comprehensive picture of tumor immune landscape before and after neoadjuvant ICB combined with chemoradiotherapy in ESCC. The infiltration of CD86 + macrophage may serve as an unfavorable indicator for neoadjuvant toripalimab combined with chemoradiotherapy.

Single-cell profiling of response to neoadjuvant chemo-immunotherapy in surgically resectable esophageal squamous cell carcinoma

BACKGROUND

The efficacy of neoadjuvant chemo-immunotherapy (NAT) in esophageal squamous cell carcinoma (ESCC) is challenged by the intricate interplay within the tumor microenvironment (TME). Unveiling the immune landscape of ESCC in the context of NAT could shed light on heterogeneity and optimize therapeutic strategies for patients.

METHODS

We analyzed single cells from 22 baseline and 24 post-NAT treatment samples of stage II/III ESCC patients to explore the association between the immune landscape and pathological response to neoadjuvant anti-PD-1 combination therapy, including pathological complete response (pCR), major pathological response (MPR), and incomplete pathological response (IPR).

RESULTS

Single-cell profiling identified 14 major cell subsets of cancer, immune, and stromal cells. Trajectory analysis unveiled an interesting link between cancer cell differentiation and pathological response to NAT. ESCC tumors enriched with less differentiated cancer cells exhibited a potentially favorable pathological response to NAT, while tumors enriched with clusters of more differentiated cancer cells may resist treatment. Deconvolution of transcriptomes in pre-treatment tumors identified gene signatures in response to NAT contributed by specific immune cell populations. Upregulated genes associated with better pathological responses in CD8 + effector T cells primarily involved interferon-gamma (IFNγ) signaling, neutrophil degranulation, and negative regulation of the T cell apoptotic process, whereas downregulated genes were dominated by those in the immune response-activating cell surface receptor signaling pathway. Natural killer cells in pre-treatment tumors from pCR patients showed a similar upregulation of gene expression in response to IFNγ but a downregulation of genes in the neutrophil-mediated immunity pathways. A decreased cellular contexture of regulatory T cells in ESCC TME indicated a potentially favorable pathological response to NAT. Cell-cell communication analysis revealed extensive interactions between CCL5 and its receptor CCR5 in various immune cells of baseline pCR tumors. Immune checkpoint interaction pairs, including CTLA4-CD86, TIGIT-PVR, LGALS9-HAVCR2, and TNFSF4-TNFRSF4, might serve as additional therapeutic targets for ICI therapy in ESCC.

CONCLUSIONS

This pioneering study unveiled an intriguing association between cancer cell differentiation and pathological response in esophageal cancer patients, revealing distinct subgroups of tumors for which neoadjuvant chemo-immunotherapy might be effective. We also delineated the immune landscape of ESCC tumors in the context of clinical response to NAT, which provides clinical insights for better understanding how patients respond to the treatment and further identifying novel therapeutic targets for ESCC patients in the future.

Diagnostic value of programmed cell death-ligand 1 expression on circulating tumor cells in lung cancer: A systematic review and meta-analysis

The expression of programmed cell death-ligand 1 (PD-L1) on circulating tumor cells offers a noninvasive method for the detection of PD-L1 expression in lung cancer, and could serve as a potential surrogate for cancer tissue. However, discrepant results make it difficult to apply PD-L1 on circulating tumor cells to clinical practice. Therefore, we conducted a meta-analysis to investigate the diagnostic value of PD-L1 on circulating tumor cells in lung cancer. To identify the relationship between the expression of PD-L1 on circulating tumor cells and lung cancer, the PubMed, Web of Science, Embase, China National Knowledge Infrastructure, and Wanfang databases were searched from inception to March 2023. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the corresponding 95% confidence intervals were calculated to assess the diagnostic performance of PD-L1. We also conducted subgroup and sensitivity analyses. A total of 11 studies including 472 lung cancer patients were included in our study. The overall performance in terms of pooled sensitivity and specificity was 0.72 (0.52-0.86) and 0.54 (0.25-0.81), respectively. The positive likelihood ratio, negative likelihood ratio, and area under the curve were 1.57 (0.87-2.84), 0.52 (0.30-0.90), and 0.70 (0.66-0.74), respectively. Deeks' funnel plot test indicated no publication bias. Our analysis demonstrated that positive PD-L1 expression on circulating tumor cells (CTCs) exhibited a moderate diagnostic value in lung cancer, and CTCs may serve as a feasible alternative tissue analysis for the detection of PD-L1 in lung cancer.

Opportunities and challenges in combining immunotherapy and radiotherapy in esophageal cancer

BACKGROUND

Immunotherapy has shown promise in the treatment of esophageal cancer, but using it alone only benefits a small number of patients. Most patients either do not have a significant response or develop secondary drug resistance. The combination of radiotherapy and immunotherapy appears to be a promising approach to treating esophageal cancer.

PURPOSE

We reviewed milestone clinical trials of radiotherapy combined with immunotherapy for esophageal cancer. We then discussed potential biomarkers for radiotherapy combined with immunotherapy, including programmed cell death-ligand 1 (PD-L1) status, tumor mutation burden (TMB), tumor-infiltrating lymphocytes, ct-DNA, imaging biomarkers, and clinical factors. Furthermore, we emphasize the key mechanisms of radiation therapy-induced immune stimulation and immune suppression in order to propose strategies for overcoming immune resistance in radiation therapy (RT). Lastly, we discussed the emerging role of low-dose radiotherapy (LDRT) , which has become a promising approach to overcome the limitations of high-dose radiotherapy.

CONCLUSION

Radiotherapy can be considered a triggering factor for systemic anti-tumor immune response and, with the assistance of immunotherapy, can serve as a systemic treatment option and potentially become the standard treatment for cancer patients.

Association of Radiochemotherapy to Immunotherapy in unresectable locally advanced Oesophageal carciNoma-randomized phase 2 trial ARION UCGI 33/PRODIGE 67: the study protocol

BACKGROUND

In case of locally advanced and/or non-metastatic unresectable esophageal cancer, definitive chemoradiotherapy (CRT) delivering 50 Gy in 25 daily fractions in combination with platinum-based regimen remains the standard of care resulting in a 2-year disease-free survival of 25% which deserves to be associated with new systemic strategies. In recent years, several immune checkpoint inhibitors (anti-PD1/anti-PD-L1, anti-Program-Death 1/anti-Program-Death ligand 1) have been approved for the treatment of various solid malignancies including metastatic esophageal cancer. As such, we hypothesized that the addition of an anti-PD-L1 to CRT would provide clinical benefit for patients with locally advanced oesophageal cancer. To assess the efficacy of the anti-PD-L1 durvalumab in combination with CRT and then as maintenance therapy we designed the randomized phase II ARION (Association of Radiochemotherapy with Immunotherapy in unresectable Oesophageal carciNoma- UCGI 33/PRODIGE 67).

METHODS

ARION is a multicenter, open-label, randomized, comparative phase II trial. Patients are randomly assigned in a 1:1 ratio in each arm with a stratification according to tumor stage, histology and centre. Experimental arm relies on CRT with 50 Gy in 25 daily fractions in combination with FOLFOX regimen administrated during and after radiotherapy every two weeks for a total of 6 cycles and durvalumab starting with CRT for a total of 12 infusions. Standard arm is CRT alone. Use of Intensity Modulated radiotherapy is mandatory. The primary endpoint is to increase progression-free survival at 12 months from 50 to 68% (HR = 0.55) (power 90%; one-sided alpha-risk, 10%). Progression will be defined with central external review of imaging.

ANCILLARY STUDIES ARE PLANNED

PD-L1 Combined Positivity Score on carcinoma cells and stromal immune cells of diagnostic biopsy specimen will be correlated to disease free survival. The study of gut microbiota will aim to determine if baseline intestinal bacteria correlates with tumor response. Proteomic analysis on blood samples will compare long-term responder after CRT with durvalumab to non-responder to identify biomarkers.

CONCLUSION

Results of the present study will be of great importance to evaluate the impact of immunotherapy in combination with CRT and decipher immune response in this unmet need clinical situation.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT: 03777813.Trial registration date: 5th December 2018.

Safety and efficacy of camrelizumab combined with radiotherapy as neoadjuvant therapy for locally advanced esophageal squamous cell carcinoma: a prospective single-arm phase II clinical trial protocol

BACKGROUND

Neoadjuvant chemoradiotherapy followed by esophagectomy is the standard of care for locally advanced esophageal squamous cell carcinoma (ESCC). However, approximately 30% of patients still develop distant metastases and have a high incidence of treatment-related adverse events. Immunotherapy, as a new modality for anti-cancer treatment, has shown promising clinical benefits for patients with ESCC. The synergistic effects of immunotherapy and radiotherapy make their combination promising as neoadjuvant treatment for locally advanced ESCC.

METHODS

All participants who meet the inclusion criteria will be enrolled after signing the informed consent form. Patients with thoracic segment esophageal cancer with clinical stage T2-3 N0 M0 or T2-3 N + M0 will be included. A total of 25 patients are to be recruited for the study. Twelve patients will be recruited in phase I, with at least two achieving major pathological response (MPR) before entering phase II. They will be treated with radical surgery within 4-8 weeks after the completion of two cycles of neoadjuvant radiotherapy in combination with camrelizumab according to the study schedule. The primary endpoint is the major pathological remission rate of all per-protocol patients. The secondary endpoints are the R0 resection rate, pathological complete remission rate, and adverse events. The interim analysis will be conducted after 12 patients have been enrolled. The trials will be terminated when more than two treatment-related deaths occur or fewer than five patients have major pathological remission.

DISCUSSION

We designed this prospective single-arm phase II clinical study to evaluate the combination of camrelizumab and standard radiotherapy as preoperative neoadjuvant therapy for patients with resectable ESCC as part of the quest for better treatment options for patients with locally advanced ESCC.

TRIAL REGISTRATION

This trial protocol has been registered on the NIH Clinical Trials database ( www.

CLINICALTRIALS

gov/ , NCT05176002. Registered on 2022/01/04). The posted information will be updated as needed to reflect protocol amendments and study progress.

Exosomal PIK3CB promotes PD-L1 expression and malignant transformation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC), which accounts for 90% of esophageal carcinomas, seriously endangers human health. Worse still, the 5-year overall survival of ESCC is approximately 20%. Elucidation of the potential mechanism and exploration of promising drugs for ESCC are urgently needed. In this study, a high level of exosomal PIK3CB protein was found in the plasma of ESCC patients, which might indicate a poor prognosis. Moreover, a significant Pearson's correlation was observed at the protein level between exosomal PIK3CB and exosomal PD-L1. Further study revealed that cancer cell-intrinsic and exosome-derived PIK3CB promoted the transcriptional activity of the PD-L1 promoter in ESCC cells. Moreover, treatment with exosomes with lower levels of exosomal PIK3CB decreased the protein level of the mesenchymal marker β-catenin while increasing that of the epithelial marker claudin-1, indicating the potential regulation of epithelial-mesenchymal transition. Consequently, the migratory ability and cancer stemness of ESCC cells and the growth of tumors formed by ESCC cells were decreased with the downregulation of exosomal PIK3CB. Therefore, exosomal PIK3CB plays an oncogenic role by promoting PD-L1 expression and malignant transformation in ESCC. This study may provide new insight into the inherent biological aggressiveness and the poor response to currently available therapies of ESCC. Exosomal PIK3CB may be a promising target for the diagnosis and therapy of ESCC in the future.

Radiotherapy combined with immune checkpoint inhibitors in locally advanced/metastatic esophageal squamous cell carcinoma: clinical trials, efficacy and future directions

Esophageal squamous cell carcinoma (ESCC) is a common malignancy worldwide and often diagnosed at advanced stages with poor prognosis. Combination of radiotherapy and immunotherapy seems to be a promising approach for treating ESCC. This comprehensive review article summarizes the current state of combination of radiotherapy and immunotherapy in locally advanced/metastatic ESCC, delineates the clinical trials that merit attention, and outlines unresolved issues and future research directions in this field. The clinical trial findings suggest that radio-immunotherapy combination may improve tumor response and overall survival with manageable side effects, highlighting the importance of patient selection and the necessity for further research to optimize treatment strategies. Issues such as irradiation dosage, fractionation regimen, irradiation site and technique of radiotherapy, as well as the timing, sequence and duration of combination therapy will all affect treatment outcomes, justifying further in-depth investigation.

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

BACKGROUND

Neoadjuvant docetaxel plus cisplatin and 5-FU (NAC-DCF) and adjuvant nivolumab monotherapy are the standard care for locally advanced resectable esophageal squamous cell carcinoma (ESCC). However, no effective biomarkers have been found in perioperative setting. We investigated how programmed death-ligand 1 (PD-L1) changes before and after NAC-DCF and how it relates to the therapeutic effect of NAC-DCF in resectable ESCC.

METHODS

PD-L1 expression in paired diagnostic biopsy and surgically resected tissues from ESCC patients who underwent surgical resection after receiving two or three NAC-DCF cycles was evaluated. PD-L1 positivity was defined as a combined positive score (CPS) of 10% ≤ . Gene expression analysis was conducted using samples before NAC-DCF.

RESULTS

Sixty-six paired samples from 33 patients were included in PD-L1 expression analysis, and 33 Pre-NAC samples acquired by diagnostic biopsy were included in gene expression analysis. Pretreatment, 3 (9%), 13 (39%), and 17 (52%) patients harbored tumors with CPS ranges of < 1%, 1%-10%, and 10% ≤ , respectively. After NAC-DCF, 5 (15%), 15 (45%), and 13 (39%) tumors presented CPS ranges of < 1%, 1%-10%, and 10% ≤ , respectively. The concordance rate between Pre-and Post-NAC-DCF samples was 45%. Patients with PD-L1-negative tumors both before and after NAC-DCF (n = 9) had shorter survival and different gene expression profile characterized by upregulation in WNT signaling or neutrophils.

CONCLUSIONS

A substantial PD-L1 expression alteration was observed, resulting in low concordance rate before and after NAC-DCF. Tumors persistently lacking PD-L1 had distinct gene expression profile with worse clinical outcomes, raising the need for further investigation.

Neoadjuvant chemoradiotherapy plus tislelizumab followed by surgery for esophageal carcinoma (CRISEC study): the protocol of a prospective, single-arm, phase II trial

BACKGROUND

The failure rate after neoadjuvant chemoradiotherapy followed by surgery is approximately 34.6%-48% for resectable esophageal carcinoma. Pathologic complete response after neoadjuvant chemoradiotherapy is an important factor in predicting lower recurrence and better survival. Whether the sequential addition of immunotherapy to neoadjuvant chemoradiotherapy will be beneficial to improving the pathologic complete response rate is unknown.

METHODS

Patients with pathologically confirmed thoracic esophageal squamous cell carcinoma and at clinical T1-2N1-3M0 or T3-4aN0-3M0 (stage II-IVA) according to the eighth edition of American Joint Committee on Cancer staging will be allocated to receive neoadjuvant radiotherapy (41.4 Gy with 23 fractions to planning target volume) with concurrent chemotherapy (albumin-bound paclitaxel, 100 mg/m2, once weekly for five weeks; carboplatin, area under the curve of 2 mg/mL/min, once weekly for five weeks) plus tislelizumab monotherapy sequentially (200 mg every three weeks for three cycles, beginning from the first to the 14th day after the end of radiotherapy). Then, subtotal esophagectomy with two-field lymphadenectomy, including the whole mediastinum and abdomen, will be performed. The primary endpoint for this study is the pathologic complete response rate after neoadjuvant chemoradiotherapy plus tislelizumab.

DISCUSSION

The optimal timing of the combination of immunotherapy and neoadjuvant chemoradiotherapy in esophageal carcinoma is not determined. The results of this phase II trial will be helpful to clarify the safety and efficacy of the sequential addition of tislelizumab after neoadjuvant chemoradiotherapy for locally advanced resectable esophageal carcinoma.

TRIAL REGISTRATION

This study was approved on January 26, 2021 and retrospectively registered with ClinicalTrials.gov ( NCT04776590 ) on March 1, 2021.

Research Progress on the Predicting Factors and Coping Strategies for Postoperative Recurrence of Esophageal Cancer

Esophageal cancer is one of the malignant tumors with poor prognosis in China. Currently, the treatment of esophageal cancer is still based on surgery, especially in early and mid-stage patients, to achieve the goal of radical cure. However, esophageal cancer is a kind of tumor with a high risk of recurrence and metastasis, and locoregional recurrence and distant metastasis are the leading causes of death after surgery. Although multimodal comprehensive treatment has advanced in recent years, the prediction, prevention and treatment of postoperative recurrence and metastasis of esophageal cancer are still unsatisfactory. How to reduce recurrence and metastasis in patients after surgery remains an urgent problem to be solved. Given the clinical demand for early detection of postoperative recurrence of esophageal cancer, clinical and basic research aiming to meet this demand has been a hot topic, and progress has been observed in recent years. Therefore, this article reviews the research progress on the factors that influence and predict postoperative recurrence of esophageal cancer, hoping to provide new research directions and treatment strategies for clinical practice.

Neoadjuvant immune checkpoint inhibitor in combination with chemotherapy or chemoradiotherapy in resectable esophageal cancer: A systematic review and meta-analysis

Background

Neoadjuvant immune checkpoint inhibitor in combination with chemotherapy (nICT) or chemoradiotherapy (nICRT) has been tested in resectable esophageal cancer. Nevertheless, efficacy and safety for this new strategy have not been clearly demonstrated.

Patients and methods

PubMed, Embase, Cochrane Library, Web of Science, and scientific meetings were searched for eligible trials until June 30, 2022. The primary outcome of interest was pathological complete response (pCR). The random-effect model was used for statistical analysis.

Results

Twenty-seven trials with 809 patients were identified. The estimated rates of pCR for nICRT and nICT were comparable (32.7%, 95% CI: 20.3%-45.1% vs 26.3%, 95% CI: 19.8%-32.8%; P = 0.37). As for safety, surgical resection rate, R0 resection rate, surgical delay rate, and surgical mortality rate were similar between nICRT and nICT, while more grade ≥3 treatment-related adverse events were observed for nICRT (52.6%, 95% CI: 30.7%-74.5% vs 19.9%, 95% CI: 8.8%-31.0%; P = 0.01). In subgroup analysis, nICRT achieved higher pCR rate compared to nICT (56.2%, 95% CI: 41.0%-71.3% vs 27.2%, 95% CI: 20.2%-34.1%; P < 0.001) for squamous cell carcinoma (SCC) but adenocarcinoma. In patients receiving nICT, PD-L1 expression CPS ≥1 showed higher pCR rate compared to CPS <1 (51.3%, 95% CI: 41.4%-61.2% vs 26.6%, 95% CI: 8.6%-44.5%; P = 0.02); regimen of paclitaxel plus carboplatin/cisplatin (PC/TP) and 3-4 cycles of nICT did not lead to an significantly improved pCR rate compared to other chemotherapy regimens and 2 cycles of nICT, respectively, despite without increased toxicity.

Conclusion

Both nICT and nICRT achieved promising pCR rates with acceptable tolerability, and nICRT was likely to have more antitumor efficacy compared to nICT for patients with SCC. PD-L1 status seemed to be predictive of pCR in patients receiving nICT; pCR rate did not appear to be greatly affected by CT regimen and increasing cycles of nICT.

Effect of neoadjuvant therapy on tumor tissue PD-L1 and VISTA expression levels in non-small-cell lung cancer

Background: PD-L1 and VISTA are important checkpoint control stations and play an immunomodulatory role in patients with non-small-cell lung cancer. Method: The expression levels of PD-L1 and VISTA between pre- and post-treatment tumor tissue were compared. Results: While PD-L1 expression was >1% in 35% of patients before neoadjuvant therapy, PD-L1 expression was >1% in 65% of patients after treatment (p = 0.004). VISTA expression was >1% in 41% of patients before treatment, and this rate was 65% after treatment (p = 0.025). Conclusion: Chemotherapy and chemoradiotherapy can be used as immunizers by increasing PD-L1 and VISTA expression levels.

Change in PD-L1 and CD8 Expression after Chemoradiotherapy for Esophageal Squamous Cell Carcinoma

Esophageal cancer has a dismal prognosis with a five-year survival rate below 20%. Recently, immunotherapy has become a new standard of care for this cancer; therefore, we aimed to examine the programmed death ligand 1 (PD-L1) expression in esophageal squamous cell carcinoma (ESCC) tissues before and after concurrent chemoradiation therapy (CCRT). In total, 64 patients with pre-CCRT ESCC specimens were examined for PD-L1 expression, with twenty-three of them having a partial response (N = 23) or stable disease (N = 1) after CCRT while post-CCRT tissue specimens were collected. All of them were tested for PD-L1 and 15 of them also had CD8 expression in the paired ESCC samples. The prevalence of PD-L1 positivity was 54.7% and we found a trend of decreased PD-L1 expression and increased CD8 positive signal after CCRT. High pre-CCRT PD-L1 H-score in tumors was related to poor prognosis (adjusted hazard ratio = 2.81; p = 0.02), although CD8 signal was not associated with overall survival either in pre- or post-CCRT treatment. In conclusion, we found that PD-L1 expression tended to decrease in CCRT responders and our result supports PD-L1 expression in tumor as a predictor of ESCC prognosis.

Absolute lymphocyte count and C-reactive protein-albumin ratio can predict prognosis and adverse events in patients with recurrent esophageal cancer treated with nivolumab therapy

Predicting the prognosis and adverse events (AEs) of nivolumab therapy for recurrent esophageal cancer is very important. The present study investigated whether a simple blood biochemical examination could be used to predict prognosis and AEs following nivolumab treatment for relapse of esophageal cancer. A total of 41 patients who received nivolumab treatment for recurrent esophageal cancer after esophagectomy were analyzed. The absolute lymphocyte count (ALC), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR) and C-reactive protein-albumin ratio (CAR) were assessed at the time of nivolumab induction as indices that can be calculated by blood biochemical examinations alone. Median values were 1,015 for ALC, 3.401 for NLR, 242.6 for PLR, 0.458 for MLR and 0.119 for CAR, and patients were divided into two groups according to values. A high ALC, low NLR, low PLR, low MLR and low CAR were associated with a better response to nivolumab. In addition, patients with the aforementioned indices, with the exception of low PLR, or better response were more likely to develop AEs in univariate analysis. In multivariate analysis, a high ALC [odds ratio (OR): 4.857, P=0.043] and low CAR (OR: 9.099, P=0.004) were identified as independent risk factors for AEs. Survival analysis revealed that overall survival and progression-free survival (PFS) rates after nivolumab treatment differed significantly between the high and low groups of ALC, NLR, PLR, MLR and CAR. The multivariate analysis identified a low ALC [hazard ratio (HR): 3.710, P=0.003] and high CAR (HR: 2.953, P=0.007) as independent poor prognostic factors of PFS. In conclusion, ALC and CAR have potential as biomarkers for outcomes of recurrent esophageal cancer following nivolumab treatment.

Chemoradiation-induced alteration of programmed death-ligand 1, CD8+ tumor-infiltrating lymphocytes and mucin expression in rectal cancer

Introduction: DNA damage and resulting neoantigen formation is considered a mechanism for synergy between radiotherapy and PD-1/PD-L1 pathway inhibition to induce antitumor immune response. We investigated neoadjuvant chemoradiotherapy (nCRT)-induced changes in CD8+ tumor infiltrating lymphocyte, PD-L1 and mucin expression in rectal cancer patients.

Materials and Methods: Tumor samples of rectal adenocarcinoma patients undergoing resection between 2008-2014 with (n = 62) or without (n = 17) nCRT treatment were collected. Sections were stained with CD8 and PD-L1 antibodies for immunohistochemistry. The prevalence of CD8+ cells was recorded in the tumor, interface tumor and background rectal side. Image analysis was used to determine the density of CD8+ lymphocytes. The percentage of PD-L1 expression was manually counted in tumor cells (TC), tumor stroma (TS) and the invasive front (IF). Mucin expression was determined as the percentage of the mucin area in the whole tumor area.

Results: PD-L1 expression on TCs was identified in 7.6% (6/79) of nCRT specimens (p = 0.33) and in none of the non-nCRT patients. Median densities of CD8+ infiltrating T lymphocytes did not differ significantly between the two groups. Mucin expression was significantly higher in the nCRT cohort (p = 0.02). Higher neutrophil to lymphocytes ratio (NLR) after nCRT was associated with worse outcome (HR = 1.04, 95% CI = 1.00–1.08).

Conclusions: nCRT exposure was associated with a non-significant difference in PD-L1 expression in rectal adenocarcinoma patients, possibly due to sample size limitations. Further mechanistic investigations and comprehensive immune analysis are needed to understand nCRT-induced immunologic shift in rectal cancer and to expand the applicability of checkpoint inhibitors in this setting.

Possible Association between the Use of Proton Pump Inhibitors and H2 Receptor Antagonists, and Esophageal Cancer: A Nested Case-Control Study Using a Korean National Health Screening Cohort

Although safety concerns regarding proton pump inhibitor (PPI)/H2-receptor antagonists (H2RA) in the incident esophageal cancer have been raised, the Asian-based report is unclear. We investigated the estimated likelihood of incident esophageal cancer—its mortality depending on prior history of PPI/H2RA use—and gastroesophageal reflux disease (GERD) in Koreans. Using the Korean National Health Insurance Service-Health Screening Cohort data (2002−2015), a case−control study was retrospectively conducted, including 811 patients with incident esophageal cancer and 3244 controls matched with sex, age, income, and residence. Propensity score overlap weighting was adjusted to balance the baseline covariates. Overlap propensity score-weighted logistic regression analyses were assessed to determine associations of the prior exposure of PPI/H2RA (current vs. past) and the medication duration (<30-, 30−90-, vs. ≥90-days) with incident esophageal cancer and its mortality among the total participants or those with/without the GERD episodes, after adjusting for multiple covariates including PPI/H2RA. The current exposure to either PPI or H2RA showed higher odds for incident esophageal cancer than the nonuser group ([13.23; 95%CI 10.25−17.06] and [4.34; 95%CI 3.67−5.14], respectively), especially in all adults over the age of 40 years without GERD. Both current and past exposures to PPI showed a decreased probability of mortality compared with those of the nonuser group ([0.62; 95%CI 0.45−0.86] and [0.41; 95%CI 0.25−0.67], respectively). However, current or past exposure to H2RA harbored the mutually different likelihoods for mortality depending on the presence of GERD and old age. This study carefully speculates on the possible link between PPI/H2RA and incident esophageal cancer in the Korean population. Mortality appears to be affected by certain risk factors depending on drug types, exposure history, old age, and the presence of GERD.

Durvalumab and tremelimumab with definitive chemoradiotherapy for locally advanced esophageal squamous cell carcinoma

BACKGROUND

The current standard treatment for patients with inoperable, locally advanced esophageal squamous cell carcinoma (ESCC) is definitive concurrent chemoradiotherapy (CCRT).

METHODS

Patients with locally advanced ESCC received 2 cycles of 5-fluorouracil, cisplatin, durvalumab, and tremelimumab every 3 weeks with concurrent radiation therapy (60.2 or 64.5 grays). After completing CCRT plus immunotherapy, patients received 2 cycles of consolidative durvalumab and tremelimumab followed by durvalumab monotherapy every 4 weeks for 2 years after enrollment. Their survival outcomes were compared with those from a propensity score-matched historical control group that had received CCRT alone.

RESULTS

In total, 40 patients were enrolled and analyzed. The 24-month progression-free survival (PFS) and overall survival rates were 57.5% and 75%, respectively. Compared with the historical control group (n = 75), the study population had significantly longer PFS (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.28-0.97; P = .040) and overall survival (HR, 0.49; 95% CI, 0.25-0.98; P = .043). In the study population, patients who had PD-L1-positive tumors (n = 28) had significantly longer PFS (HR, 0.20; 95% CI, 0.07-0.54; P < .001) and overall survival (HR, 0.16; 95% CI, 0.05-0.56; P = .001) compared with those who had PD-L1-negative tumors (n = 11). However, there was no difference in survival outcomes according to PD-L1 status in the historical control group, indicating a strong interaction between PD-L1-positive status and survival outcomes in the treatment groups (PFS, P for interaction = .003; overall survival, P for interaction = .002).

CONCLUSIONS

Durvalumab and tremelimumab with definitive CCRT had promising efficacy in patients with locally advanced ESCC. In addition, PD-L1 expression had strong predictive value in the study population.

Roles of PTEN inactivation and PD-1/PD-L1 activation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer in China and developing countries. The purpose of this review is to summarize the roles of inactivation of the tumor suppressor gene, phosphatase and tensin homolog (PTEN), and activation of the programmed cell death protein 1 (PD-1) upon binding to its ligand (PD-L1) in the promotion of ESCC. Studies of ESCC performed in vitro and in vivo indicated that PTEN and PD-L1 function in the regulation of cell proliferation, invasion, and migration; the epithelial-mesenchymal transition; resistance to chemotherapy and radiotherapy; and the PI3K/AKT signaling pathway. Certain genetic variants of PTEN are related to susceptibility to ESCC, and PTEN and PD-L1 also function in ESCC progression and affect the prognosis of patients with ESCC. There is also evidence that the expression of PD-L1 and PTEN are associated with the progression of certain other cancers. Future studies should further examine the relationship of PD-L1 and PTEN and their possible interactions in ESCC.

Nivolumab-DTPA-Based PD-1 Imaging Reveals Structural and Pathological Changes in Colorectal Carcinoma

Programmed cell death protein 1 (PD-1) expression is considered a prognostic marker of tumor response to the immuno-blocking therapy. In this study, nivolumab was conjugated with diethylenetriamine pentaacetate (DTPA) via condensation reaction between amidogen and p-SCN-Bn-DTPA, which provided labeling sites for 99mTc4+ or Gd3+ ions. SPECT and magnetic resonance T1 weighted imaging (T1WI) analyses were performed on mouse models of colorectal carcinoma expressing humanized PD-1 antigen. Furthermore, PD-1 expression in intestinal tracks was assessed by immunohistochemistry, and then compared with the imageological findings. Nivolumab-DTPA was synthesized with varying molar ratios and was labeled with Gd or 99mTc with a chemical purity of 96.28 ± 1.16% and good stability. In SPECT images, lesions with high 99mTc-DTPA-nivolumab uptake and relatively clear background were shown at 6 h. Thereafter, the suspected intestinal thickening in Gd-free T1WI was observed at 2 h after the addition of Gd-DTPA-nivolumab. Notably, the results of both SPECT and T1WI analyses were consistent with the postmortem examination and immunohistochemistry results (for linear correlation with target to non-target ratios, R2 = 0.8038, p &lt; 0.05). In conclusion, nivolumab-DTPA could act as a probe precursor for identifying PD-1-positive lesions, not only through integrating the advantages of immunohistochemistry and molecular imaging but also by providing a noninvasive method for monitoring systemic changes.

Adjuvant durvalumab for esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy: a placebo-controlled, randomized, double-blind, phase II study

BACKGROUND

We evaluated the efficacy of adjuvant durvalumab after neoadjuvant concurrent chemoradiotherapy (CCRT) in patients with esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

This randomized, double-blind, phase II study included patients with ESCC who underwent curative surgery after neoadjuvant CCRT. Patients were randomized to receive either durvalumab (20 mg/kg/i.v. every 4 weeks for 12 months) or placebo in a 1:1 ratio and were stratified by age and pathologic tumor stage. The primary endpoint was disease-free survival (DFS).

RESULTS

Between March 2016 and June 2018, 86 patients were randomized to the durvalumab (n = 45) or placebo (n = 41) arm. The median follow-up duration was 38.7 months. There was no difference in DFS [hazard ratio (HR) 1.18, 95% confidence interval (CI) 0.62-2.27, P = 0.61] or overall survival (HR 1.08, 95% CI 0.52-2.24, P = 0.85) between the two arms. Subgroup analysis was performed for patients for whom the post-CCRT programmed death-ligand 1 (PD-L1) expression profile could be assessed (n = 54). In the PD-L1-positive group, based on tumor proportion score ≥1%, durvalumab was associated with longer overall survival compared with the placebo (36-month survival rate: 94% versus 64%; HR 0.42, 95% CI 0.10-1.76), while in the PD-L1-negative group, it was associated with shorter overall survival (42% versus 55%; HR 1.53, 95% CI 0.48-4.83), showing the tendency of interaction between post-CCRT PD-L1 status and adjuvant durvalumab therapy for overall survival (interaction P = 0.18).

CONCLUSIONS

We failed to demonstrate that adjuvant durvalumab improved survival after neoadjuvant CCRT in patients with ESCC. However, post-CCRT PD-L1 expression could predict the survival of patients who receive adjuvant durvalumab after neoadjuvant CCRT, which needs to be validated.

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis

BACKGROUND

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors.

METHODS

We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification.

RESULTS

One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70).

CONCLUSIONS

High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

Expression of non-homologous end joining factor, Ku80, is negatively correlated with PD-L1 expression in cancer cells after X-ray irradiation

The growing importance of antitumour immunity by cancer immunotherapy has prompted studies on radiotherapy-induced immune response. Previous studies have indicated that programmed cell death-1 ligand (PD-L1) expression is regulated by DNA damage signalling. However, PD-L1 up-regulation after radiotherapy has not been fully investigated at the clinical level, particularly in the context of expression of DNA repair factors. The present study examined the correlation of mRNA expression between PD-L1 and non-homologous end joining (NHEJ) factors using The Cancer Genome Atlas database analysis. Among NHEJ factors, Ku80 mRNA expression was negatively correlated with PD-L1 mRNA expression levels in several types of cancer (colon adenocarcinoma, breast invasive carcinoma, skin cutaneous melanoma, lung adenocarcinoma, head and neck squamous cell carcinoma, uterine corpus endometrial carcinoma, cervical squamous cell carcinoma and endocervical adenocarcinoma). To verify the negative correlation in clinical samples, the present study analysed whether Ku80 expression levels affected PD-L1 up-regulation after radiotherapy using cervical squamous cell carcinoma samples. Quantitative evaluation using software analysis of immunohistochemically stained slides revealed that patients with low Ku80 positivity in biopsy specimens demonstrated increased PD-L1 expression levels after 10 Gy irradiation (Spearman's rank correlation coefficient=−0.274; P=0.017). Furthermore, PD-L1 induction levels in tumour cells after 10 Gy of irradiation were significantly inversely correlated with Ku80 expression levels (Spearman's rank correlation coefficient=−0.379; P<0.001). The present study also confirmed that short interfering RNA-mediated Ku80 depletion was associated with greater X-ray-induced PD-L1 up-regulation in HeLa cells. These results indicated that radiotherapy could enhance PD-L1 induction in tumour cells with low Ku80 expression in a clinical setting. Furthermore, these data highlighted Ku80 as a potential predictive biomarker for immune checkpoint therapy combined with radiotherapy.

Programmed death ligand 2 expression plays a limited role in adenocarcinomas of the gastroesophageal junction after preoperative chemotherapy

Background

The effects of cytotoxic chemotherapy on the expression of programmed death ligand 2 (PD-L2) are unknown and little is known about how the tumor microenvironment changes following neoadjuvant chemotherapy in locally advanced gastroesophageal adenocarcinomas (AEG). Recently, a number of studies reported that cytotoxic chemotherapy affects the expression levels of programmed cell death protein 1 (PD-1) and its ligand 1 (PD-L1). Regarding PD-L2, the second known ligand of PD‑1, no data on potential changes in expression patterns in patients with preoperatively treated AEG are available. The aim of this study was to investigate the impact of cytotoxic chemotherapy on PD-L2 expression in patients with resectable AEG.

Methods

Consecutive patients with locally advanced AEG treated with preoperative cytotoxic chemotherapy were included. PD-L2 expression by cancer cells (CCs) and tumor-infiltrating lymphocytes (TILs) was investigated in samples of paired diagnostic biopsies and resected tumor specimens by immunohistochemistry using two different anti-PD-L2 antibodies.

Results

Included were 40 patients with AEG and available paired tumor tissue samples. PD-L2 expression was observed in one diagnostic biopsy sample by CCs and in one diagnostic biopsy sample by TILs. There was no difference concerning the expression levels measured by the two antibodies.

Conclusion

In contrast to previously published studies reporting PD-L2 expression rates of up to 50% in AEGs, in our cohort, PD-L2 expression seems to play no significant role in AEG.

Prognostic implication of PD-L1 polymorphisms in non-small cell lung cancer treated with radiotherapy

Background

To investigate the impact of programmed death‐ligand 1 (PD‐L1) polymorphisms on the prognosis of non‐small cell lung cancer (NSCLC) patients treated with curative radiotherapy.

Methods

Four single nucleotide polymorphisms (SNPs) (rs822336G>C, rs822337T>A, rs822338C>T, and rs2297136A>G) in the PD‐L1 gene were evaluated in 124 NSCLC patients. Clinical stage was I in 28, II in 17, and III in 79 patients. Fifty‐seven patients received radiotherapy alone, including 28 patients who received stereotactic body radiotherapy. Sixty‐seven patients received sequential or concurrent chemoradiotherapy. Risk factors for survival outcomes were analyzed with the log‐rank test and multivariate Cox proportional hazards models.

Results

The rs822336GC+CC genotype was associated with better overall survival (OS) (hazard ratio [HR] = 0.60, 95% confidence interval [CI] = 0.37–0.97, p = 0.036) and regional failure‐free survival (RFFS) (HR = 0.32, 95% CI = 0.14–0.76, p = 0.009), compared with rs822336GG genotype. The rs822337TA+AA genotype was associated with better OS (HR =0.54, 95% CI = 0.34–0.88, p = 0.014), progression‐free survival (PFS) (HR = 0.64, 95% CI = 0.41–0.99, p = 0.046), and RFFS (HR = 0.38, 95% CI = 0.17–0.81, p = 0.013), compared with rs822337TT genotype. Three SNPs (rs822336, rs822337, and rs822338) were in linkage disequilibrium. Combined GTC and GTT (GT*) haplotype was associated with significantly worse OS (p = 0.018), PFS (p = 0.044), and RFFS (p = 0.038), compared with those with other combined haplotypes. Patients with diplotypes of two GT* haplotypes showed significantly worse OS (p = 0.023) and RFFS (p = 0.014) than those with other diplotypes.

Conclusions

These findings suggest that PD‐L1 polymorphisms could be predictive markers for NSCLC patients receiving radiotherapy.

Pembrolizumab plus chemotherapy versus chemotherapy alone for first-line treatment of advanced oesophageal cancer (KEYNOTE-590): a randomised, placebo-controlled, phase 3 study

BACKGROUND

First-line therapy for advanced oesophageal cancer is currently limited to fluoropyrimidine plus platinum-based chemotherapy. We aimed to evaluate the antitumour activity of pembrolizumab plus chemotherapy versus chemotherapy alone as first-line treatment in advanced oesophageal cancer and Siewert type 1 gastro-oesophageal junction cancer.

METHODS

We did a randomised, placebo-controlled, double-blind, phase 3 study across 168 medical centres in 26 countries. Patients aged 18 years or older with previously untreated, histologically or cytologically confirmed, locally advanced, unresectable or metastatic oesophageal cancer or Siewert type 1 gastro-oesophageal junction cancer (regardless of PD-L1 status), measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1, and Eastern Cooperative Oncology Group performance status of 0-1, were randomly assigned (1:1) to intravenous pembrolizumab 200 mg or placebo, plus 5-fluorouracil and cisplatin (chemotherapy), once every 3 weeks for up to 35 cycles. Randomisation was stratified by geographical region, histology, and performance status. Patients, investigators, and site staff were masked to group assignment and PD-L1 biomarker status. Primary endpoints were overall survival in patients with oesophageal squamous cell carcinoma and PD-L1 combined positive score (CPS) of 10 or more, and overall survival and progression-free survival in patients with oesophageal squamous cell carcinoma, PD-L1 CPS of 10 or more, and in all randomised patients. This trial is registered with ClinicalTrials.gov, NCT03189719, and is closed to recruitment.

FINDINGS

Between July 25, 2017, and June 3, 2019, 1020 patients were screened and 749 were enrolled and randomly assigned to pembrolizumab plus chemotherapy (n=373 [50%]) or placebo plus chemotherapy (n=376 [50%]). At the first interim analysis (median follow-up of 22·6 months), pembrolizumab plus chemotherapy was superior to placebo plus chemotherapy for overall survival in patients with oesophageal squamous cell carcinoma and PD-L1 CPS of 10 or more (median 13·9 months vs 8·8 months; hazard ratio 0·57 [95% CI 0·43-0·75]; p<0·0001), oesophageal squamous cell carcinoma (12·6 months vs 9·8 months; 0·72 [0·60-0·88]; p=0·0006), PD-L1 CPS of 10 or more (13·5 months vs 9·4 months; 0·62 [0·49-0·78]; p<0·0001), and in all randomised patients (12·4 months vs 9·8 months; 0·73 [0·62-0·86]; p<0·0001). Pembrolizumab plus chemotherapy was superior to placebo plus chemotherapy for progression-free survival in patients with oesophageal squamous cell carcinoma (6·3 months vs 5·8 months; 0·65 [0·54-0·78]; p<0·0001), PD-L1 CPS of 10 or more (7·5 months vs 5·5 months; 0·51 [0·41-0·65]; p<0·0001), and in all randomised patients (6·3 months vs 5·8 months; 0·65 [0·55-0·76]; p<0·0001). Treatment-related adverse events of grade 3 or higher occurred in 266 (72%) patients in the pembrolizumab plus chemotherapy group versus 250 (68%) in the placebo plus chemotherapy group.

INTERPRETATION

Compared with placebo plus chemotherapy, pembrolizumab plus chemotherapy improved overall survival in patients with previously untreated, advanced oesophageal squamous cell carcinoma and PD-L1 CPS of 10 or more, and overall survival and progression-free survival in patients with oesophageal squamous cell carcinoma, PD-L1 CPS of 10 or more, and in all randomised patients regardless of histology, and had a manageable safety profile in the total as-treated population.

FUNDING

Merck Sharp & Dohme.

Narrative review of pembrolizumab for the treatment of esophageal cancer: evidence and outlook

Objective

Based on the current evidence, review the efficacy and safety profile of pembrolizumab, along with its shortcomings, in an effort to define future research directions.

Background

The survival outcome of esophageal cancer (EC) is poor, especially in patients with advanced stage. Palliative surgery, chemotherapy, radiotherapy and chemoradiotherapy have limited efficacy in prolonging the survival time. Currently, immunotherapies, including adoptive cell therapy-based, antibody-based, and vaccine-based therapies, are attracting considerable attention. The mechanism of immunotherapy lies in the modification of immune response and prevention of immune escape. Immunomodulatory agents can block the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) pathway, thereby allowing lymphocytes to attack tumor cells. This class of drugs has the potential to treat a variety of tumors and may substantially improve overall survival (OS) in some patients. Multiple clinical trials have shown that pembrolizumab has good efficacy and safety, enhances the EC treatment paradigm, and has even become the first-line treatment of choice for patients with PD-L1-positive recurrent or metastatic EC.

Methods

We reviewed the results of clinical trials of pembrolizumab for EC and gastroesophageal cancer presented at Embase, PubMed, the American Society of Clinical Oncology (ASCO) annual meetings, and the Cochrane Central Register of Controlled Trials.

Conclusions

Pembrolizumab has good efficacy and tolerability profiles, and has emerged as a second-line option for the treatment of PD-L1-positive locally advanced or metastatic ESCC. Pembrolizumab has many promising applications, and further investigations into its mechanisms should be conducted.

Prognostic value of PD-L1 expression on immune cells or tumor cells for locally advanced esophageal squamous cell carcinoma in patients treated with neoadjuvant chemoradiotherapy

PURPOSE

Programmed death-ligand 1 (PD-L1) expression may influence the prognosis of patients with localized esophageal cancer. The current study compared the prognostic value of PD-L1 expression between tumor cells and immune cells.

METHODS

Archival esophageal tumor tissue samples were collected from patients who received paclitaxel and cisplatin-based neoadjuvant chemoradiotherapy (CRT) for locally advanced esophageal squamous cell carcinoma (ESCC) in three prospective phase II trials. PD-L1 expression on tumor and immune cells was examined immunohistochemically by using the SP142 antibody and scored by two independent pathologists. The association of PD-L1 expression with patient's outcomes was analyzed using a log-rank test and Cox regression multivariate analysis.

RESULTS

A total of 100 patients were included. PD-L1 expression on tumor cells was positive (≥ 1%, TC-positive) in 55 patients; PD-L1 expression on immune cells was high (≥ 5%, IC-high) in 30 patients. TC-positive status was associated with poor overall survival (OS) (HR: 1.63, P = 0.035), whereas IC-high status was associated with improved OS (HR: 0.44, P = 0.0024). Multivariate analysis revealed that TC-positive, IC-high, and performance status were independent prognostic factors for progression-free survival and that IC-high and performance status were independent factors for OS. Furthermore, the combination of IC-high and TC-negative status was associated with the optimal OS, whereas that of TC-positive and IC-low status was associated with the worst OS.

CONCLUSION

PD-L1 expression on tumor and immune cells may have different prognostic value for patients with locally advanced ESCC receiving neoadjuvant CRT. A combination of these two indexes may further improve the prognostic prediction.

Expression of programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand (PD-L1) in adenocarcinomas of the gastroesophageal junction change significantly after neoadjuvant treatment

BACKGROUND

The effects of cytotoxic chemotherapy on the expression of programmed cell death 1 (PD-1) and its ligand (PD-L1) in cancer cells and peritumoral cells are unclear. The aim of this study was to investigate the impact of neoadjuvant chemotherapy on PD-1 and PD-L1 expression in adenocarcinomas of the gastroesophageal junction.

METHODS

PD-1 and PD-L1 expression in cancer cells and tumor-infiltrating lymphocytes in paired diagnostic biopsies and surgical specimens from patients with pretreated and curatively resected adenocarcinomas of the gastroesophageal junction were evaluated by immunohistochemistry.

RESULTS

Paired tumor samples were available from 40 patients. PD-1 expression in cancer cells (p < 0.001; Exact Symmetry Test) and tumor-infiltrating lymphocytes (p < 0.001; Exact Symmetry Test) increased significantly after neoadjuvant therapy. Furthermore, we observed a significant decrease in PD-L1 expression in cancer cells (p = 0.003) after neoadjuvant therapy was observed.

CONCLUSION

In this study we could show that tumor-cell expression of PD-1 and PD-L1 was significantly altered in patients with adenocarcinomas of the gastroesophageal junction after receiving neoadjuvant chemotherapy. Based on these observations, patients might profit from the combined use of cytotoxic chemotherapy and the blockade of the PD-1 axis.

Clinicopathological and prognostic values of PD-L1 expression in oesophageal squamous cell carcinoma: a meta-analysis of 31 studies with 5368 patients

Several immune checkpoint inhibitors targeting programmed death ligand 1 (PD-L1)/programmed death 1 have successfully improved the prognosis of oesophageal squamous cell carcinoma (ESCC) with approval in certain countries. However, whether the expression of PD-L1 is associated with the degree of benefit is unclear yet and a unified standard of antibody and cut-off value of PD-L1 detection is also lacking. The current meta-analysis then aimed to explore the association between PD-L1 expression and clinicopathological features as well as prognosis in ESCC.A systematic search on PubMed, Embase, Cochrane Library and Web of Science databases was performed up to 30 March 2021. The correlation between PD-L1 expression and clinicopathological features, as well as prognosis in ESCC, was estimated with the random-effects model.A total of 5368 patients from 31 retrospective studies were enrolled. The overexpression of PD-L1 was significantly associated with lymph node metastasis (OR 1.342, 95% CI 0.995 to 1.809, p=0.050) and distant metastasis (OR 1.516, 95% CI 1.001 to 2.294, p=0.050). The pooled HR showed that PD-L1 overexpression was significantly correlated with poor overall survival (OS) of patients with ESCC (HR 1.306, 95% CI 1.108 to 1.539, p<0.010) but not disease-free survival (DFS) (HR 1.180, 95% CI 0.937 to 1.487, p=0.160). Heterogeneity decreased significantly in subgroup analyses. The overexpression of PD-L1 was associated with poor DFS at the cut-off point of ≥1% (HR 1.642, 95% CI 1.367 to 1.973, p<0.010; I²=0%) and worse OS at the cut-off point of ≥10% (HR 1.575, 95% CI 1.175 to 2.111, p<0.010; I²=0%).The overexpression of PD-L1 was correlated with lymph node and distant metastasis as well as poor survival of ESCC.

PD-L1 expression in recurrent head and neck squamous cell carcinoma

PURPOSE

To evaluate the Programmed Cell Death Ligand (PD-L1) expression at diagnosis and relapse in patients with head and neck carcinoma (HNSCC) treated with radio(chemo)therapy.

METHODS

PD-L1 immunohistochemistry was performed in tumor cells (TC) and immune cells (IC) in 44 patients and scored as 0 = 0%, 1 =  < 5%, 2 = 6-49% or 3 =  ≥ 50% cells.

RESULTS

PD-L1 expression on TC before RT was scored as 0, 1, 2 and 3 in 28, 4, 8 and 4 patients, respectively. In 10 patients, IC did not show any PD-L1 expression; while in 8, 16, and 10 patients, PD-L1 expression was scored 1, 2 and 3, respectively. At relapse, 7/36 patients had a PD-L1 expression positivation in TC, while the opposite was observed in 6 patients. Overall, survival at 2 years was higher in patients with PD-L1 expression (90% versus 62.5%, p = 0.032).

CONCLUSION

PD-L1 expression may vary throughout the course of the disease. A re-evaluation of PD-L1 expression on biopsies at the time of recurrence should be recommended.

An update on the use of immunotherapy in patients with colorectal cancer

Introduction: Colorectal cancer (CRC) is the third most common malignancy worldwide, with recent trends demonstrating increasing incidence amongst younger patients. Despite multiple treatment options, metastatic disease remains incurable. A new therapeutic strategy to harness the host immune system, specifically with immune checkpoint inhibitors, now has reported results from a number of clinical trials. Areas covered: This review will discuss in detail microsatellite instability (MSI) and other biomarkers for response to immunotherapy, summarize the pivotal clinical trials of immune checkpoint inhibitors in early-stage and metastatic MSI colorectal cancer, explore strategies to induce treatment responses in MSS CRC and highlight the emerging treatments and novel immune-based therapies under investigation. Expert opinion: Immunotherapy is now a standard of care for the proportion of CRC patients with MSI. While overall survival data are still awaited, the promise of profound and durable responses is highly anticipated. The lack of efficacy in MSS CRC is disappointing and strategies to convert these 'cold' tumors are needed. Further elucidation of optimal use of treatment sequences, combinations and novel agents will improve outcomes.

Prognostic Impact of PD-1 on Tumor-Infiltrating Lymphocytes in 433 Resected Esophageal Cancers

BACKGROUND

Immune checkpoint inhibitors targeting the programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway have demonstrated antitumor effects in patients with various malignancies, including esophageal cancer. Thus, a better understanding of local immunity in esophageal cancer is crucial for improving treatment and clinical outcomes.

METHODS

We evaluated PD-1 expression on tumor-infiltrating lymphocytes (TILs), as well as PD-L1 expression on cancer cells, by immunohistochemistry and immunofluorescence using a nonbiased database of 433 curatively resected esophageal cancers. With the idea of application as liquid biopsy, PD-1 expression status on peripheral lymphocytes was evaluated by flow cytometry.

RESULTS

The cutoff value of PD-1 expression was the median PD-1 count. Compared with cases of low PD-1 expression (n = 219), cases with high levels of PD-1 expression (n = 213) showed significantly worse overall survival (log-rank P = .0017). The prognostic effect of PD-1 differed according to the preoperative treatment status (P for interaction = .040); PD-1 expression was associated with high overall mortality among patients without preoperative therapy, while no such association was present among those with preoperative treatment. A stratification based on PD-1 and PD-L1 status was also significantly associated with overall survival (log-rank P = .0005). PD-1 expression on TILs was significantly associated with that on peripheral lymphocytes (P < .0001).

CONCLUSIONS

PD-1 expression on TILs was associated with an unfavorable clinical outcome in esophageal cancer, supporting its role as a prognostic biomarker. The combination of PD-1 and PD-L1 expression enabled further classification of patients according to clinical outcome.

Effect of radiotherapy on T cell and PD-1 / PD-L1 blocking therapy in tumor microenvironment

Cancer is a worldwide problem that threatens human health. Radiotherapy plays an important role in a variety of cancer treatment methods. The administration of radiotherapy can alter the differentiation pathways and functions of T cells, which in turn improves the immune response of T cells. Radiotherapy can also induce up-regulation of PD-L1 expression, which means that it has great potential for enhancing the therapeutic effect of anti-PD-1/PD-L1 inhibitors and reducing the risk of drug resistance toward them. At present, the combination of radiotherapy and anti-PD-1/PD-L1 inhibitors has shown significant therapeutic effects in clinical tumor research. This review focuses on the mechanism of radiotherapy on T cells reported in recent years, as well as related research progress in the application of PD-1/PD-L1 blockers. It will provide a theoretical basis for the rational clinical application of radiotherapy combined with PD-1/PD-L1 inhibitors.

Plasma Biomarkers Screening by Multiplex ELISA Assay in Patients with Advanced Non-Small Cell Lung Cancer Treated with Immune Checkpoint Inhibitors

Simple Summary

There is an unmet need for new predictive biomarkers associated with efficacy and immune-related toxicity of immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC). In this study, we performed multiplex ELISA screening in plasma from 35 consecutive patients with advanced NSCLC treated with nivolumab or pembrolizumab, allowing large-scale screening for 48 cytokines involved in immune response and tumour proliferation. We found an association between ICIs efficacy and three cytokines: soluble hepatocyte growth factor (sHGF), soluble Fibroblast Growth Factor (sFGF) and interleukine-12 (IL-12). Moreover, TNF-α, IL-16, IL-12p40 and MCP3 were candidate biomarkers for predicting grade 3–4 immune-related toxicity. This exploratory study shows the potential role of new plasma biomarkers in advanced NSCLC treated with ICIs.

Abstract

Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lung cancer (NSCLC). An unmet need remains for new biomarkers associated with ICIs. In this study, consecutive patients with advanced NSCLC treated with nivolumab or pembrolizumab were included. Plasma at ICIs initiation was prospectively collected and a multiplex ELISA assay testing 48 cytokines and growth factors was performed. Exploratory endpoints were the association between plasma biomarkers with outcome and grade III–IV immune related adverse events (irAEs). Thirty-five patients were included. Patients without clinical benefit (n = 22) had higher pre-ICI soluble Hepatocyte Growth Factor (sHGF) (210.9 vs. 155.8 pg/mL, p = 0.010), lower pre-ICI soluble Fibroblast Growth Factor (sFGF) (4.0 vs. 4.8 pg/mL, p = 0.043) and lower pre-ICI interleukine-12 (IL-12) (1.3 vs. 2.2 pg/mL, p = 0.043) concentrations. Patients with early progression (n = 23) had higher pre-ICIs sHGF (206.2 vs. 155.8 pg/mL, p = 0.025) concentrations. Patients with low sHGF levels at ICIs initiation had longer progression-free survival and overall survival than those with high sHGF levels: respectively 2.5 vs. 8.0 months (p = 0.002), and 5.5 vs. 35.0 months (p = 0.001). TNF-α, IL-16, IL-12p40 and MCP3 were associated with high grade irAEs. This study shows the potential association between several plasma biomarkers with outcome and grade 3–4 IrAEs in advanced NSCLC treated with ICIs.

Significance of druggable targets (PD-L1, KRAS, BRAF, PIK3CA, MSI, and HPV) on curatively resected esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) still remains intractable disease with few therapeutic options. Programmed death-ligand 1 (PD-L1), which is essential for immune evasion, is involved in the pathogenesis of ESCC and thus is a potential therapeutic target. PIK3CA, KRAS, and BRAF mutations, microsatellite instability (MSI) caused by deficient mismatch repair (dMMR), and human papillomavirus (HPV) can potentially upregulate PD-L1 expression, which might contribute to the clinical outcome of patients with ESCC.

Methods

We investigated the significance of the present druggable markers [PD-L1, PIK3CA, KRAS, and BRAF mutations, MSI caused by deficient dMMR, and HPV] in 64 curatively resected ESCCs, using immunohistochemistry (PD-L1 and MMR protein expression), direct sequencing (KRAS, BRAF, and PIK3CA mutations), real-time PCR (HPV infection), and MSI using quasi-monomorphic markers.

Results

PD-L1 expression, PIK3CA mutation, and MSI/dMMR were detected in 35.9, 12.5, and 17.2% of ESCCs, respectively. HPV was rarely detected (1.6%) (high-risk HPV68), whereas KRAS and BRAF mutations were not detected in ESCCs. PD-L1-positive tumors were not correlated with PIK3CA mutation or MSI/dMMR (all P > 0.05). PD-L1, PIK3CA mutation, and MSI/dMMR characterized the patients associated with light smoking, female and younger age, and younger age and well-differentiated tumors, respectively (all P < 0.05). In multivariate analysis, only PD-L1-positivity was an independent favorable prognostic factor for overall survival (OS) and disease-free survival (DFS) (P = 0.023, P = 0.014). In the PD-L1-negative ESCCs, PIK3CA mutation had a poor prognostic impact on both OS and DFS (P = 0.006, P = 0.002).

Conclusions

PIK3CA mutation may be an alternative prognostic biomarker in PD-L1-negative curatively resected ESCCs that can be optional to identify high-risk patients with worse clinical outcome who require more intensive therapy and follow-up.

Advances in the pharmacotherapeutic management of esophageal squamous cell carcinoma

INTRODUCTION

Esophageal squamous cancer remains an important cause of mortality worldwide with two new immunotherapy drugs recently approved for metastatic disease.

AREAS COVERED

The authors review the epidemiology and genomics of esophageal squamous cell carcinoma. They also examine prior trials involving targeted agents under investigation as well immunotherapies that have been approved and novel combinations.

EXPERT OPINION

Great advances have been made in characterizing the molecular changes in esophageal carcinoma. However, relatively few drugs have shown benefit in this disease. Targeted therapies have not shown to improve survival although many of these trials did not explore potential biomarkers. Pembrolizumab and nivolumab are now approved for esophageal squamous carcinoma but much more data are needed to understand how these agents may be used in non-metastatic settings. Novel treatments are still required as overall prognosis remains poor.

Enhancing the efficacy of immunotherapy using radiotherapy

Recent clinical breakthroughs in cancer immunotherapy, especially with immune checkpoint blockade, offer great hope for cancer sufferers - and have greatly changed the landscape of cancer treatment. However, whilst many patients achieve clinical responses, others experience minimal benefit or do not respond to immune checkpoint blockade at all. Researchers are therefore exploring multimodal approaches by combining immune checkpoint blockade with conventional cancer therapies to enhance the efficacy of treatment. A growing body of evidence from both preclinical studies and clinical observations indicates that radiotherapy could be a powerful driver to augment the efficacy of immune checkpoint blockade, because of its ability to activate the antitumor immune response and potentially overcome resistance. In this review, we describe how radiotherapy induces DNA damage and apoptosis, generates immunogenic cell death and alters the characteristics of key immune cells in the tumor microenvironment. We also discuss recent preclinical work and clinical trials combining radiotherapy and immune checkpoint blockade in thoracic and other cancers. Finally, we discuss the scheduling of immune checkpoint blockade and radiotherapy, biomarkers predicting responses to combination therapy, and how these novel data may be translated into the clinic.

Radiotherapy Scheme Effect on PD-L1 Expression for Locally Advanced Rectal Cancer

In locally advanced rectal cancer, radiotherapy (RT) followed by surgery have improved locoregional control, but distant recurrences remain frequent. Although checkpoint inhibitors have demonstrated objective response in several cancers, the clinical benefit of PD-1/PD-L1 blockade remains uncertain in rectal cancer. We collected data from biopsies and surgical specimens in 74 patients. The main objective was to evaluate the impact of neoadjuvant RT and fractionation on PD-L1 expression. Secondary objectives were to study the relation between PD-L1 expression and tumor regression grade (TRG), progression-free survival (PFS), overall survival (OS), and CD8 TILs infiltration. Median rates of cells expressing PD-L1 pre- and post-RT were 0.15 (range, 0-17) and 0.5 (range, 0-27.5), respectively (p = 0.0005). There was no effect of RT fractionation on PD-L1+ cell rates. We found no relation between CD8+ TILs infiltration and PD-L1 expression and no difference between high-PD-L1 or low-PD-L1 expression and TRG. High-to-high PD-L1 expression profile had none significant higher OS and PFS compared to all other groups (p = 0.06). Median OS and PFS were higher in biopsies with >0.08 PD-L1+ cells. High-to-high PD-L1 profile and ypT0-2 were significantly associated with higher OS and PFS. This study did not show the differential induction of PD-L1 expression according to fractionation.

DNA Repair and Signaling in Immune-Related Cancer Therapy

Cancer therapy using immune checkpoint inhibitors (ICIs) is a promising clinical strategy for patients with multiple types of cancer. The expression of programmed cell death ligand-1 (PD-L1), an immune-suppressor ligand, in cancer cells is a factor that influences the efficacy of ICI therapy, particularly in the anti-programmed cell death protein-1 (PD-1)/PD-L1 antibody therapy. PD-L1 expression in cancer cells are associated with tumor mutation burden including microsatellite instability because the accumulation of mutations in the cancer genome can produce abnormal proteins via mutant mRNAs, resulting in neoantigen production and HLA-neoantigen complex presentation in cancer cells. HLA-neoantigen presentation promotes immune activity within tumor environment; therefore, known as hot tumor. Thus, as the fidelity of DNA repair affects the generation of genomic mutations, the status of DNA repair and signaling in cancer cells can be considered prior to ICI therapy. The Cancer Genome Atlas (TCGA) and The Cancer Immunome Atlas (TCIA) database analysis showed that tumor samples harboring mutations in any non-homologous end joining, homologous recombination, or DNA damage signaling genes exhibit high neoantigen levels. Alternatively, an urgent task is to understand how the DNA damage-associated cancer treatments change the status of immune activity in patients because multiple clinical trials on combination therapy are ongoing. Recent studies demonstrated that multiple pathways regulate PD-L1 expression in cancer cells. Here, we summarize the regulation of the immune response to ICI therapy, including PD-L1 expression, and also discuss the potential strategies to improve the efficacy of ICI therapy for poor responders from the viewpoint of DNA damage response before or after DNA damage-associated cancer treatment.

An individualized immune signature of pretreatment biopsies predicts pathological complete response to neoadjuvant chemoradiotherapy and outcomes in patients with esophageal squamous cell carcinoma

No clinically available biomarkers can predict pathological complete response (pCR) for esophageal squamous cell carcinomas (ESCCs) with neoadjuvant chemoradiotherapy (nCRT). Considering that antitumor immunity status is an important determinant for nCRT, we performed an integrative analysis of immune-related gene profiles from pretreatment biopsies and constructed the first individualized immune signature for pCR and outcome prediction of ESCCs through a multicenter analysis. During the discovery phase, 14 differentially expressed immune-related genes (DEIGs) with greater than a twofold change between pCRs and less than pCRs (<pCRs) were revealed from 28 pretreatment tumors in a Guangzhou cohort using microarray data. Ten DEIGs were verified by qPCR from 30 cases in a Beijing discovery cohort. Then, a four-gene-based immune signature (SERPINE1, MMP12, PLAUR, and EPS8) was built based on the verified DEIGs from 71 cases in a Beijing training cohort, and achieved a high accuracy with an area under the receiver operating characteristic curve (AUC) of 0.970. The signature was further validated in an internal validation cohort and an integrated external cohort (Zhengzhou and Anyang cohorts) with AUCs of 0.890 and 0.859, respectively. Importantly, a multivariate analysis showed that the signature was the only independent predictor for pCR. In addition, patients with high predictive scores showed significantly longer overall and relapse-free survival across multiple centers (P < 0.05). This is the first, validated, and clinically applicable individualized immune signature of pCR and outcome prediction for ESCCs with nCRT. Further prospective validation may facilitate the combination of nCRT and immunotherapy.

Prognosis of Lung Adenocarcinoma Patients With NTRK3 Mutations to Immune Checkpoint Inhibitors

Background

Immune checkpoint inhibitors (ICIs) are an important treatment modality that must be considered for patients with lung adenocarcinoma (LUAD). However, ICIs are effective only in some of these patients. Therefore, identifying biomarkers that accurately predict the prognosis of patients with LUAD treated with ICIs can help maximize their therapeutic benefits. This study aimed to identify a new potential predictor to better select and optimally benefit LUAD patients.

Methods

We first collected and analyzed a discovery immunotherapy cohort comprising clinical and mutation data for LUAD patients. Then, we evaluated whether the specific mutated genes can act as predictive biomarkers in this discovery immunotherapy cohort and further validated the findings in The Cancer Genome Atlas (TCGA) project LUAD cohort. Gene set enrichment analysis (GSEA) was used to explore possible alterations in DNA damage response (DDR) pathways within the gene mutation. Moreover, we analyzed whole-exome sequencing (WES) and drug sensitivity response data for LUAD cell lines in the Genomics of Drug Sensitivity in Cancer (GDSC) database.

Results

Among the mutated genes screened from both the ICI treatment and TCGA-LUAD cohorts, NTRK3 mutation (mutant-type NTRK3, NTRK3-MT) was strongly associated with immunotherapy. First, significant differences in overall survival (OS) were observed between patients with NTRK3-MT and those with NTRK3-WT in the ICI treatment cohort but not in the non-ICI-treated TCGA-LUAD cohort. We then analyzed the association of NTRK3-MT with clinical characteristics and found the tumor mutation burden (TMB) to be significantly higher in both NTRK3-MT cohorts. However, significant differences in neoantigen levels and smoking history were found only for NTRK3-MT in the LUAD cohort from TCGA. Furthermore, some immune-related genes and immune cell-related genes were significantly upregulated in patients with NTRK3-MT compared to those with NTRK3-WT. In addition, NTRK3 mutation affected the deregulation of some signaling pathways and the DDR pathway.

Conclusions

Our findings suggest that NTRK3-MT can predict the prognosis of patients with LUAD treated by ICIs and that it may have clinical significance for immunotherapy.

Changes in immune parameters between pre-treatment and recurrence after (chemo) radiation therapy in patients with head and neck cancer

Squamous cell carcinoma of the head and neck (SCCHN) has a high recurrence rate after (chemo) radiation therapy [(C)RT]. The relationship between the changing levels of immune checkpoint molecules and immune cells in pre-(C)RT tissues and locally recurrent tissues in the irradiated field, after (C)RT completion, is not known. This study aimed to assess the changes in these immune parameters between pre-(C)RT tissue and the same area after local recurrence post-(C)RT. We retrospectively reviewed 30 (C)RT-treated patients with SCCHN. We performed immunohistochemical analyses on these immune parameters using paired tissue samples obtained pre-(C)RT and at local recurrence sites post-(C)RT. No significant changes in immune parameters were found between the pre-(C)RT and locally recurrent tissues. An increased density of CD8+ tumor-infiltrating lymphocytes (TILs) showed a significantly positive correlation with PD-L expression on tumor cells (TC-PD-L1). Patients with increased TC-PD-L1 expression and CD8+TIL density showed favourable prognosis, and one of them showed a favourable response to nivolumab therapy. Our study shows a positive association between TC-PD-L1 upregulation and increased CD8+TIL density, and demonstrates that patients with these changes have a favourable survival outcome.

IDO1 Expression Increased After Neoadjuvant Therapy Predicts Poor Pathologic Response and Prognosis in Esophageal Squamous Cell Carcinoma

Indoleamine 2,3-dioxygenase (IDO1) plays an important role in tumor immune evasion. In this study, we investigated the changes of tumor IDO1 expression and CD8+ tumor-infiltrating lymphocytes (TILs) status in tumor microenvironment (TME) after neoadjuvant chemoradiotherapy (NCRT) or neoadjuvant chemotherapy (NCT) in esophageal squamous cell carcinoma (ESCC), respectively. Moreover, the potential predictive value of the changes of tumor IDO1 expression and CD8+TILs status on pathologic response and clinical outcome was further evaluated. By matching propensity scores in 295 patients, a total of 85 ESCC patients with neoadjuvant therapy followed by surgery were recruited, including 17 patients with NCRT and 68 patients with NCT. Tumor IDO1 expression and CD8+TILs within TME in paired specimens were evaluated by immunohistochemistry, and the changes of tumor IDO1 expression and CD8+TILs between the paired specimens were estimated. Tumor IDO1 expression significantly increased from baseline to postoperative tumor tissue after NCT (p = 0.002), whereas no significant difference was detected after NCRT (p = 0.44). The density of CD8+TILs in the tumor-invasive margin increased significantly after neoadjuvant therapy, and there was no significant difference in density changes of CD8+TILs between the NCRT and NCT groups (p = 0.118). Upregulation of tumor IDO1 expression after neoadjuvant therapy was associated with poor pathologic response (p = 0.002). Lastly, multivariate Cox analysis showed that IDO1-rise patients after neoadjuvant therapy were related to poor prognosis (p = 0.047). These results indicated that chemotherapy could promote tumor IDO1 expression, and the increased tumor IDO1 expression after neoadjuvant therapy predicted poor pathologic response and prognosis in ESCC.

Synergism Between Immunotherapy and Radiotherapy in Esophageal Cancer: An Overview of Current Knowledge and Future Perspectives

Background: Esophageal cancer (EC) is an aggressive neoplasm of the gastrointestinal tract that is usually treated with a combination of chemotherapy, radiotherapy (RT), and/or surgery, according to disease status. Despite the availability of multimodal therapeutic strategies, local recurrence is frequently observed. Immunotherapy is a promising therapeutic approach that is currently highly investigated in association to standard therapies, including RT, with the aim to improve patients' outcomes. Materials and Methods: A PubMed search was performed with the following keywords in all fields: "esophageal cancer" and "radiotherapy" and "radiation" and "immunotherapy" and "PD-1" and "PD L1." For an overview of ongoing trials, an additional search on ClinicalTrials.gov website was performed using the keywords "esophageal cancer" and "immunotherapy" and "PD-L1" and "CTLA-4" and "radiation" and "radiotherapy." Emerging data from preclinical and clinical studies are suggesting a synergistic effect between immunotherapy and RT. With the aim to update the knowledge of this synergistic immune-mediated antitumor activity and discuss current challenges, the authors summarize published data concerning the basic mechanisms and the effectiveness and tolerance of the combination between immunotherapy and RT for patients with EC, followed by an overview of ongoing clinical trial. Conclusions: Published results encourage the use of personalized therapeutic approaches for EC patients in the future; results from ongoing studies will help to identify the optimal strategies for patient selection and treatment response evaluation.

Priming the tumor immune microenvironment with chemo(radio)therapy: A systematic review across tumor types

BACKGROUND

Chemotherapy (CT), radiotherapy (RT), and chemoradiotherapy (CRT) are able to alter the composition of the tumor immune microenvironment (TIME). Understanding the effect of these modalities on the TIME could aid in the development of improved treatment strategies. Our aim was to systematically review studies investigating the influence of CT, RT or CRT on different TIME markers.

METHODS

The EMBASE (Ovid) and PubMed databases were searched until January 2019 for prospective or retrospective studies investigating the dynamics of the local TIME in cancer patients (pts) treated with CT, RT or CRT, with or without targeted agents. Studies could either compare baseline and follow-up specimens - before and after treatment - or a treated versus an untreated cohort. Studies were included if they used immunohistochemistry and/or flow cytometry to assess the TIME.

RESULTS

In total we included 110 studies (n = 8850 pts), of which n = 89 (n = 6295 pts) compared pre-treatment to post-treatment specimens and n = 25 (n = 2555 pts) a treated versus an untreated cohort (4 studies conducted both comparisons). For several tumor types (among others; breast, cervical, esophageal, ovarian, rectal, lung mesothelioma and pancreatic cancer) remodeling of the TIME was observed, leading to a potentially more immunologically active microenvironment, including one or more of the following: an increase in CD3 or CD8 lymphocytes, a decrease in FOXP3 Tregs and increased PD-L1 expression. Both CT and CRT were able to immunologically alter the TIME.

CONCLUSION

The TIME of several tumor types is significantly altered after conventional therapy creating opportunities for concurrent or sequential immunotherapy.

Rationale of combination of anti-PD-1/PD-L1 antibody therapy and radiotherapy for cancer treatment

Significant technological advances in radiotherapy have been made in the past few decades. High-precision radiotherapy has recently become popular and is contributing to improvements in the local control of the irradiated target lesions and the reduction of adverse effects. Accordingly, for long-term survival, the importance of systemic cancer control, including at non-irradiated sites, is growing. Toward this challenge, the treatment methods in which anti-PD-1/PD-L1 antibodies that exert systemic effects by restoring anti-tumour immunity are combined with radiotherapy has attracted attention in recent years. Previous studies have reported the activation of anti-tumour immunity by radiotherapy, which simultaneously elevates PD-L1 expression, suggesting a potential for combination therapy. Radiotherapy induces so-called ‘immunogenic cell death’, which involves cell surface translocation of calreticulin and extracellular release of high-mobility group protein box 1 (HMGB-1) and adenosine-5′-triphosphate (ATP). Furthermore, radiotherapy causes immune activation via MHC class I upregulation and cGAS–STING pathway. In contrast, induction of immunosuppressive lymphocytes and the release of immunosuppressive cytokines and chemokines by radiotherapy contribute to immunosuppressive reactions. In this article, we review immune responses induced by radiotherapy as well as previous reports to support the rationale of combination of radiotherapy and anti-PD-1/PD-L1 antibodies. A number of preclinical and clinical studies have shown the efficacy of radiotherapy combined with immune checkpoint inhibition, hence combination therapy is considered to be an important future strategy for cancer treatment.