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

A narrative review on advances in neoadjuvant immunotherapy for esophageal cancer: Molecular biomarkers and future directions

Esophageal cancer has a poor prognosis and survival rate due to its high incidence in Asia, lack of early symptoms and limited treatment options. In recent years, many clinical trials have demonstrated that immunotherapy has greatly improved the survival of patients with esophageal cancer. In addition, the combination of neoadjuvant immunotherapy with other popular therapeutic regimens has shown good efficacy and safety. In this review, we summarize the progress of clinical trials and some breakthroughs in neoadjuvant immunotherapy for esophageal cancer in recent years and suggest the possibility of multimodal neoadjuvant immunotherapy regimens, as well as directions for future development.

Global esophageal cancer epidemiology in 2022 and predictions for 2050: A comprehensive analysis and projections based on GLOBOCAN data

BACKGROUND

The burden of esophageal cancer varies across different regions of the world. The aim of this study is to analyze the current burden of esophageal cancer in 185 countries in 2022 and to project the trends up to the year 2050.

METHODS

We extracted data on primary esophageal cancer cases and deaths from the GLOBOCAN 2022 database, which includes data from 185 countries. Age-standardized incidence rates (ASIR) and mortality rates (ASMR) per 100,000 person-years were calculated by stratifying by Human Development Index (HDI) levels and regions. Considering changes in population size and age structure, we assumed that the risks of incidence and mortality remain constant at the levels of 2022 to forecast the number of new cases and deaths from esophageal cancer globally by 2050.

RESULTS

In 2022, an estimated 511,054 people were diagnosed with esophageal cancer globally, and 445,391 died from the disease. The global ASIR and ASMR for esophageal cancer were 5.00 and 4.30 per 100,000, respectively. The highest rates were observed in East Africa (7.60 for incidence, 7.20 for mortality per 100,000), East Asia (7.60 for incidence, 5.90 for mortality per 100,000), Southern Africa (6.30 for incidence, 5.90 for mortality per 100,000), and South Central Asia (5.80 for incidence, 5.50 for mortality per 100,000). Among the 185 countries worldwide, esophageal cancer was among the top five causes of cancer incidence in 18 countries and among the top five causes of cancer mortality in 25 countries. In 2022, China had 224,012 new cases and 187,467 deaths from esophageal cancer, accounting for approximately 43.8% and 42.1% of the global total, respectively, which is higher than the proportion of China's population to the global population (17.9%). ASIR was 8.30 per 100,000, and ASMR was 6.70 per 100,000. The highest burden of esophageal cancer was in high HDI countries, with new cases and deaths accounting for 51.3% and 50.0% of the global total, respectively. The ASIR and ASMR were highest in the high HDI group (6.10 and 5.10 per 100,000, respectively), also exceeding the global averages. There was a trend of decreasing mortality to incidence ratio with increasing HDI, but no correlation was observed between HDI and ASIR or ASMR. In all regions worldwide, the incidence and mortality rates were higher in males than in females (with a male-to-female ASR ratio ranging from 1.10 to 28.7). Compared to 2022, it is projected that by 2050, the number of new esophageal cancer cases will increase by approximately 80.5%, and deaths will increase by 85.4% due to population growth and aging.

CONCLUSIONS

The burden of esophageal cancer remains heavy. Adopting a healthy lifestyle, including reducing tobacco and alcohol intake, avoiding moldy foods, and increasing intake of fresh fruits and vegetables, can help reduce the risk of stomach and esophageal cancer. In addition, the development and implementation of evidence-based and effective public health policies are critical to reducing the global disease burden of esophageal cancer.

Treatment strategies for elderly patients with locally advanced esophageal cancer: a systematic review and meta-analysis

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery remains a standard of care for resectable esophageal cancer (EC), and definitive chemoradiotherapy (dCRT) is an alternative for unresectable diseases. However, it is controversial for the use of the two aggressive regimens in elderly patients.

METHODS

We systematically searched multiple databases for studies comparing overall survival (OS) and/or progression-free survival (PFS) between dCRT and surgery (nCRT + surgery or surgery alone) or between dCRT and radiotherapy (RT) alone in elderly patients (age ≥ 65 years) until March 28, 2024. Statistical analysis was performed using random-effects model.

RESULTS

Fourty-five studies with 33,729 patients were included. dCRT significantly prolonged OS (hazard ratio [HR] = 0.64, 95% confidence interval [CI]: 0.58-0.70) and PFS (HR = 0.67, 95% CI: 0.60-0.76) compared to RT alone for unresectable EC, and resulted in a worse OS compared to surgery for resectable cases (HR = 1.34, 95% CI: 1.23-1.45). Similar results of OS were also observed when the multivariate-adjusted HRs were used as the measure of effect (dCRT vs. RT alone: HR = 0.65, 95% CI: 0.58-0.73; dCRT vs. surgery: HR = 1.49, 95% CI: 1.28-1.74). Subgroup analyses according to age group (≥ 70, ≥ 75, or ≥ 80 years), study design, study region, histological type, radiation field, chemotherapy regimen revealed comparable results.

CONCLUSIONS

nCRT + surgery is likely a preferred strategy for elderly patients with good physiological conditions; and dCRT is a better alternative for unresectable cases. Advanced age alone does not appear to be a key predictor for the tolerability of the two aggressive treatments.

Superior Anticancer and Antifungal Activities of New Sulfanyl-Substituted Niclosamide Derivatives

The approved anthelmintic salicylanilide drug niclosamide has shown promising anticancer and antimicrobial activities. In this study, new niclosamide derivatives with trifluoromethyl, trifluoromethylsulfanyl, and pentafluorosulfanyl substituents replacing the nitro group of niclosamide were prepared (including the ethanolamine salts of two promising salicylanilides) and tested for their anticancer activities against esophageal adenocarcinoma (EAC) cells. In addition, antifungal activity against a panel of Madurella mycetomatis strains, the most abundant causative agent of the neglected tropical disease eumycetoma, was evaluated. The new compounds revealed higher activities against EAC and fungal cells than the parent compound niclosamide. The ethanolamine salt 3a was the most active compound against EAC cells (IC50 = 0.8-1.0 µM), and its anticancer effects were mediated by the downregulation of anti-apoptotic proteins (BCL2 and MCL1) and by decreasing levels of β-catenin and the phosphorylation of STAT3. The plausibility of binding to the latter factors was confirmed by molecular docking. The compounds 2a and 2b showed high in vitro antifungal activity against M. mycetomatis (IC50 = 0.2-0.3 µM) and were not toxic to Galleria mellonella larvae. Slight improvements in the survival rate of G. mellonella larvae infected with M. mycetomatis were observed. Thus, salicylanilides such as 2a and 3a can become new anticancer and antifungal drugs.

Neoadjuvant systemic therapy for hepatocellular carcinoma

Surgical resection and liver transplant remain the only curative therapies for most patients with hepatocellular carcinoma (HCC). Systemic therapy options have typically been ineffective, but recent advances, such as the combination of immune checkpoint inhibitors and targeted therapies, have shown great promise. Neoadjuvant systemic therapy in resectable or locally advanced HCC is under active investigation with encouraging results in small, early-phase trials. Many of these completed and ongoing trials include combinations of systemic therapy (e.g. immune checkpoint inhibitors, tyrosine kinase inhibitors), transarterial therapies, and radiation. Despite early successes, larger trials with evaluation of long-term oncologic outcomes are needed to determine the role of neoadjuvant systemic therapy in patients with HCC who may be eligible for curative intent surgery or transplant.

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.

Effectiveness and safety of camrelizumab-containing neoadjuvant therapy in patients with esophageal squamous cell carcinoma: a prospective multicenter observational cohort study

BACKGROUND

Camrelizumab has been demonstrated to be a feasible treatment option for locally advanced esophageal squamous cell carcinoma (ESCC) when combined with neoadjuvant chemotherapy. This trial was conducted to investigate the effectiveness and safety of camrelizumab-containing neoadjuvant therapy in patients with ESCC in daily practice.

METHODS

This prospective multicenter observational cohort study was conducted at 13 tertiary hospitals in Southeast China. Patients with histologically or cytologically confirmed ESCC [clinical tumor-node-metastasis (cTNM) stage I-IVA] who had received at least one dose of camrelizumab-containing neoadjuvant therapy were eligible for inclusion.

RESULTS

Between June 1, 2020 and July 13, 2022, 255 patients were enrolled and included. The median age was 64 (range, 27 to 82) years. Most participants were male (82.0%) and had clinical stage III-IVA diseases (82.4%). A total of 169 (66.3%) participants underwent surgical resection; 146 (86.4%) achieved R0 resection, and 36 (21.3%) achieved pathological complete response (pCR). Grades 3-5 adverse events (AEs) were experienced by 14.5% of participants. Reactive cutaneous capillary endothelial proliferation occurred in 100 (39.2%) of participants and all were grade 1 or 2.

CONCLUSIONS

Camrelizumab-containing neoadjuvant therapy has acceptable effectiveness and safety profiles in real-life ESCC patients.

Neoadjuvant Immunotherapy for Localized Pancreatic Cancer: Challenges and Early Results

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease due to its late presentation and tendency to recur early even after optimal surgical resection. Currently, there are limited options for effective systemic therapy. In addition, PDAC typically generates an immune-suppressive tumor microenvironment; trials of immunotherapy in metastatic PDAC have yielded disappointing results. There is considerable interest in using immunotherapy approaches in the neoadjuvant setting in order to prime the immune system to detect and prevent micrometastatic disease and recurrence. A scoping review was conducted to identify published and ongoing trials utilizing preoperative immunotherapy. In total, 9 published trials and 27 ongoing trials were identified. The published trials included neoadjuvant immune checkpoint inhibitors, cancer vaccines, and other immune-modulating agents that target mechanisms distinct from that of immune checkpoint inhibition. Most of these are early phase trials which suggest improvements in disease-free and overall survival when combined with standard neoadjuvant therapy. Ongoing trials are exploring various combinations of these agents with each other and with chemotherapy and/or radiation. Rational combination immunotherapy in addition to standard neoadjuvant therapy has the potential to improve outcomes in PDAC, but further clinical trials are needed, particularly those which utilize an adaptive trial design.

Neoadjuvant adebrelimab in locally advanced resectable esophageal squamous cell carcinoma: a phase 1b trial

Overall survival (OS) benefits of neoadjuvant immunotherapy remain elusive in locally advanced esophageal squamous cell carcinomas (ESCC). Here, we reported the results of a phase 1b trial of neoadjuvant PD-L1 blockade with adebrelimab in resectable ESCC. Patients received two neoadjuvant doses of adebrelimab followed by surgery. The primary endpoints were safety and feasibility; secondary endpoints included pathologic complete response (pCR) and OS. Our data showed the primary endpoints of safety and feasibility had been met. Common treatment-related adverse events were anorexia (32%) and fatigue (16%), without grade 3 or more adverse events. Of the 30 patients enrolled in the trial, 25 underwent successful resection without surgery delay and 24% had major pathologic responses including a pCR rate of 8%. The 2-year OS was 92%. Responsive patients had an immune-enriched tumor microenvironment phenotype, whereas nonresponsive patients had greater infiltration of cancer-associated fibroblasts at baseline. Clonotypic dynamics of pre-existing intratumoral T cells was a hallmark of responsive patients. These findings provide a rational for neoadjuvant anti-PD-L1 monotherapy as a therapeutic strategy for patients with resectable ESCC. ClinicalTrials.gov identifier: NCT04215471 .

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.

New 4,5-Diarylimidazol-2-ylidene-iodidogold(I) Complexes with High Activity against Esophageal Adenocarcinoma Cells

Inspired by the vascular-disrupting agent combretastatin A-4 and recently published anticancer active N-heterocyclic carbene (NHC) complexes of Au(I), a series of new iodidogold(I)-NHC complexes was synthesized and characterized. The iodidogold(I) complexes were synthesized by a route involving van Leusen imidazole formation and N-alkylation, followed by complexation with Ag2O, transmetalation with chloro(dimethylsulfide)gold(I) [Au(DMS)Cl], and anion exchange with KI. The target complexes were characterized by IR spectroscopy, 1H and 13C NMR spectroscopy, and mass spectrometry. The structure of 6c was validated via single-crystal X-ray diffraction. A preliminary anticancer screening of the complexes using two esophageal adenocarcinoma cell lines showed promising nanomolar activities for certain iodidogold(I) complexes accompanied with apoptosis induction, as well as c-Myc and cyclin D1 suppression in esophageal adenocarcinoma cells treated with the most promising derivative 6b.

Comparison of neoadjuvant immunotherapy versus routine neoadjuvant therapy for patients with locally advanced esophageal cancer: A systematic review and meta-analysis

Background

The neoadjuvant use of immune checkpoint inhibitor combined with chemotherapy (nICT) or chemoradiotherapy (nICRT) in locally advanced esophageal cancer (EC) is currently an area of active ongoing research. Therefore, we carried out a comprehensive meta-analysis to compare the efficacy and safety of the new strategy with routine neoadjuvant strategy, which included neoadjuvant chemotherapy (nCT) and neoadjuvant chemoradiotherapy (nCRT).

Patients and methods

MEDLINE (via PubMed), Embase (via OVID), ISI Web of Science database and Cochrane Library were included. And, all of them were searched for eligible studies between January, 2000 and February, 2023. The pathological complete response (pCR) and major pathological response (MPR) were primary outcome of our study. The second outcome of interest was R0 resection rate. Odds ratio (OR) and associated 95% CI were used as the effect indicators comparing the safety and efficiency of the neoadjuvant immunotherapy with the routine neoadjuvant therapy. Fixed-effect model (Inverse Variance) or random-effect model (Mantel-Haenszel method) was performed depending on the statistically heterogeneity.

Results

There were eight trials with 652 patients were included in our meta-analysis. The estimated pCR rate was higher in the neoadjuvant immunotherapy group (OR =1.86; 95% CI, 1.25-2.75; I² = 32.8%, P=0.166). The different results were found in the esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) subgroups, the estimated OR was 2.35 (95%CI, 1.00-2.72; I² = 30.9%, P=0.215) in the EAC subgroup, and 2.35 (95% CI, 1.20-4.54; I² = 45.3%, P=0.161) in the ESCC subgroup, respectively. The neoadjuvant immunotherapy also showed the advantage in the MPR rates (OR =2.66; 95% CI, 1.69-4.19; I² = 24.3%, P=0.252). There was no obvious difference between the neoadjuvant immunotherapy and routine neoadjuvant therapy with respect to surgical resection rate, R0 resection rate, surgical delay rate; while more treatment-related adverse events were observed for the neoadjuvant immunotherapy for pneumonitis/pneumonia (OR=3.46, 95% CI, 1.31-9.16; I² = 67.3%, P=0.005) and thyroid dysfunction (OR=4.69, 95% CI, 1.53-14.36; I² = 56.5%, P=0.032).

Conclusion

The pooled correlations indicated that the neoadjuvant immunotherapy (both nICT and nICRT) could significantly increase the rates of pCR and MPR, compared with routine neoadjuvant therapy (both nCT and nCRT) in the treatment of locally advanced EC. The neoadjuvant immunotherapy and routine neoadjuvant therapy were with acceptable toxicity. However, randomized studies with larger groups of patients need to performed to confirm these results.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42020155802.