Neoadjuvant Therapy with Immune Checkpoint Inhibitors in Gastric Cancer: A Systematic Review and Meta-Analysis

Neoadjuvant chemotherapy combined with antiangiogenic therapy and immune checkpoint inhibitors for the treatment of locally advanced gastric cancer: a real - world retrospective cohort study

Background

Although immune checkpoint inhibitors (ICIs) and anti-angiogenic drugs have demonstrated effectiveness in treating advanced gastric cancer (GC), their role in neoadjuvant or conversion therapy remains uncertain. This study aimed to evaluate the efficacy and safety of combining neoadjuvant chemotherapy with anti-angiogenesis and ICIs in patients with locally advanced GC (LAGC).

Methods

In this cohort study, we reviewed our prospectively maintained GC database and included individuals diagnosed with clinical stage II-III GC who received neoadjuvant therapy followed by surgery between January 2022 and August 2023. The treatment protocol combined ICIs, anti-angiogenic therapy (specifically apatinib), and chemotherapy (S-1 with oxaliplatin). A systematic approach was used to document patients' clinical and pathological characteristics, pathological findings, and survival outcomes, which were subsequently analyzed in detail.

Results

A total of 38 individuals met the study's inclusion criteria, with the majority (32 patients, 84.2%) having clinical stage III GC. All participants underwent surgery, resulting in a notable R0 resection rate of 97.4%. The rates of major pathological response (MPR) and pathological complete response (pCR) were 47.4% and 23.7%, respectively. Post-surgery, 36 patients (92.1%) received adjuvant chemotherapy. With a median follow-up of 22 months, ten patients experienced disease recurrence, including three who died from tumor relapse. The 1-year overall survival (OS) rate stood at 100%, and the disease-free survival (DFS) rate was 94.7%, with median OS and DFS yet to be reached. The neoadjuvant therapy regimen was generally well-tolerated, with no grade 5 treatment-related adverse events (TRAEs) reported. Only one patient experienced a grade 4 TRAE (immune-related hepatitis), while the most common grade 3 TRAEs included thrombocytopenia, elevated aminotransferase levels, and neutropenia.

Conclusions

The combination of neoadjuvant chemotherapy, anti-angiogenic therapy, and ICIs has proven effective in treating LAGC patients, achieving high pCR rates and favorable survival outcomes while maintaining an acceptable safety profile.

Impact of Helicobacter pylori infection on neoadjuvant chemotherapy in locally advanced gastric cancer: a retrospective analysis

BACKGROUND

Helicobacter pylori (H. pylori) infection may affect the efficacy of immunotherapy and adjuvant chemotherapy in gastric cancer patients. However, the role of H. pylori infection in neoadjuvant chemotherapy in patients with locally advanced gastric cancer (LAGC) remains unclear. This study investigated the effect of H. pylori infection on neoadjuvant chemotherapy and prognosis of patients with LAGC.

METHODS

This retrospective study utilized data from patients with LAGC who underwent neoadjuvant chemotherapy and surgical treatment at the Sixth Affiliated Hospital of Sun Yat-sen University from January 1, 2010, to January 31, 2021. Patients were grouped according to their H. pylori infection status. The responses of the two groups to neoadjuvant chemotherapy and oncological outcomes were then compared.

RESULTS

A total of 239 patients were included in the analysis, and the baseline characteristics of the H. pylori-positive (n = 51) and H. pylori-negative (n = 188) groups were comparable. Further analysis revealed that H. pylori infection was significantly associated with the major pathological response (P = 0.009). Multivariate analysis showed that factors related to major pathological response included; age ≤ 50 (OR: 0.423, 95% CI: 0.194-0.925), H. pylori infection (OR: 0.396, 95% CI: 0.183-0.854), pathological stage T 3/4 (OR: 0.524, 95% CI: 0.288-0.954), and CA12-5 > 35 U/mL (OR: 0.345, 95% CI: 0.132-0.904). Both overall survival (OS) and disease-free survival (DFS) rates were poorer in the H. pylori-positive group than in the H. pylori-negative group (OS: Log-Rank P = 0.035; DFS: Log-Rank P = 0.029).

CONCLUSION

This cohort study indicated that H. pylori infection may be associated with tumor response to neoadjuvant chemotherapy and survival outcomes in patients with LAGC.

Chemotherapy combined with immunotherapy in patients with gastric cancer: protocol for a systematic review

INTRODUCTION

The integration of chemotherapy and immunotherapy is continually making new advances in the field of gastric cancer treatment and has already become the new standard of care for the disease. However, few systematic reviews cover a wide array of immune checkpoint inhibitors (ICIs), antibody types and therapeutic modalities (perioperative or systemic) in this domain. Our aim is to incorporate the most recent clinical studies on combination therapy for the treatment of gastric cancer into a systematic review. This will comprehensively assess the benefits and drawbacks for patients with gastric cancer and will guide future research in this area. Ultimately, this will provide evidence-based support for patients with gastric cancer.

METHODS AND ANALYSIS

This protocol for a systematic review adheres to the Preferred Reporting Items for Systematic Review and Meta-analysis - Protocols (PRISMA-P) guidelines. We will conduct a search of the MEDLINE, Embase, and CENTRAL databases from database inception, all retrieved literature will be screened by two authors in two rounds. Inclusion criteria will be randomised clinical trials, reported in English, that compare immunotherapy-combined therapy with chemotherapy alone in the perioperative and systematic first-line treatment of gastric cancer. The primary outcomes will be progression-free survival (PFS) and overall survival (OS). Secondary outcomes will include objective response rate (ORR), event-free survival (EFS), disease-free survival (DFS), pathologic complete response (pCR), major pathologic response (MPR), and the R0 resection rate. Heterogeneity and publication bias of included literature will be investigated. Where included literatures allow, we will conduct meta-analyses and subgroup analyses to further refine the pros and cons of combined therapy, providing evidence-based foundations for subsequent research.

ETHICS AND DISSEMINATION

This work is a review based on existing literature and no ethical review is required. Dissemination of the results will occur via academic journal publication, conference presentations, and multiple media platforms.

PROSPERO REGISTRATION NUMBER

CRD42023477353.

Perioperative immune checkpoint inhibitors combined with chemotherapy versus chemotherapy for locally advanced, resectable gastric or gastroesophageal junction adenocarcinoma: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Immunotherapy in combination with chemotherapy has been approved as an initial treatment strategy for unresectable advanced gastric cancer (GC). However, the efficacy of adding immunotherapy to perioperative chemotherapy in locally advanced resectable gastric or gastroesophageal junction adenocarcinoma (GC/GEJC) remains uncertain. Therefore, a meta-analysis of randomized controlled trials (RCTs) was performed to compare the effectiveness of perioperative immune checkpoint inhibitors (ICIs) plus chemotherapy versus chemotherapy alone in patients with locally advanced resectable GC/GEJC.

METHODS

A comprehensive search of online databases was conducted to identify RCTs published until November 30, 2023. Odds ratios (ORs) with 95% confidence interval (CI) were calculated for primary outcomes, including R0 resection rate, D2 lymphadenectomy, pathologic complete response (pCR), and treatment-related adverse events (TRAEs).

RESULTS

A total of 2718 patients from five RCTs (six reports) were included in the analysis. The pooled ORs of R0 resection rate and D2 lymphadenectomy demonstrated that combination therapy with ICIs showed no significant difference compared to chemotherapy alone. However, the addition of ICIs significantly improved pCR rates (OR = 3.43, 95 % CI 2.61-4.50, p < 0.0001). There were no significant differences observed in the incidence of any grade TRAEs and grade 3-4 TRAEs. However, ICIs combination therapy was associated with significantly higher incidences of any grade irAEs (OR = 4.03, 95 % CI: 2.70-6.00, p < 0.0001), as well as grade 3-4 irAEs (OR = 4.51, 95 % CI: 2.27-8.97, p < 0.0001).

CONCLUSIONS

This study represents the first meta-analysis to demonstrate that perioperative combination therapy with ICIs yields superior pCR rates for patients with locally advanced GC/GEJC compared to chemotherapy.

Potent therapeutic strategy in gastric cancer with microsatellite instability-high and/or deficient mismatch repair

Gastric cancer (GC) is a common malignancy that presents challenges in patient care worldwide. The mismatch repair (MMR) system is a highly conserved DNA repair mechanism that protects genome integrity during replication. Deficient MMR (dMMR) results in an increased accumulation of genetic errors in microsatellite sequences, leading to the development of a microsatellite instability-high (MSI-H) phenotype. Most MSI-H/dMMR GCs arise sporadically, mainly due to MutL homolog 1 (MLH1) epigenetic silencing. Unlike microsatellite-stable (MSS)/proficient MMR (pMMR) GCs, MSI-H/dMMR GCs are relatively rare and represent a distinct subtype with genomic instability, a high somatic mutational burden, favorable immunogenicity, different responses to treatment, and prognosis. dMMR/MSI-H status is a robust predictive biomarker for treatment with immune checkpoint inhibitors (ICIs) due to high neoantigen load, prominent tumor-infiltrating lymphocytes, and programmed cell death ligand 1 (PD-L1) overexpression. However, a subset of MSI-H/dMMR GC patients does not benefit from immunotherapy, highlighting the need for further research into predictive biomarkers and resistance mechanisms. This review provides a comprehensive overview of the clinical, molecular, immunogenic, and therapeutic aspects of MSI-H/dMMR GC, with a focus on the impact of ICIs in immunotherapy and their potential as neoadjuvant therapies. Understanding the complexity and diversity of the molecular and immunological profiles of MSI-H/dMMR GC will drive the development of more effective therapeutic strategies and molecular targets for future precision medicine.

The safety and efficacy of neoadjuvant PD-1 inhibitor plus chemotherapy for patients with locally advanced gastric cancer: A systematic review and meta-analysis

BACKGROUND

The extensive utilization of immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) has achieved significant advancements in the treatment of diverse solid tumors. The present meta-analysis aims to evaluate the safety and efficacy of neoadjuvant chemotherapy (NCT) plus PD-1 inhibitor for patients with locally advanced gastric cancer (LAGC).

METHODS

An electronic search of PubMed, EmBase, and the Cochrane Library was performed to identify the clinical trials of NCT + PD-1 inhibitor vs. NCT in patients with LAGC. The retrieval period extended from the establishment of the corresponding database until April 2024, and meta-analysis was conducted using Stata (version 15) software. Subsequently, direct comparative analysis was used to compare pooled results of neoadjuvant immunochemotherapy (NICT) with NCT.

RESULTS

After screening, 6 phase II/III randomized controlled trials (RCTs) and 9 retrospective studies with 2,953 patients were included. In meta-analysis, NICT group demonstrated a significantly higher rate of pathological complete response (pCR) (P<0.001) and R0 resection (P=0.001), and a lower 2-year recurrence rate (P=0.001) compared to the NCT group. The NICT group, however, exhibited a higher incidence of severe treatment-related adverse events (TRAEs) (P=0.044). Additionally, the NICT and NCT groups exhibited no statistical differences in terms of the number of harvested lymph nodes, the occurrence of total TRAEs and postoperative complications, as well as the duration of postoperative hospitalization.

CONCLUSIONS

The combination of PD-1 inhibitor + NCT in LAGC patients enhances the likelihood of achieving radical surgery and improves prognosis, albeit to some extent increasing the risk of severe TRAEs. NICT is anticipated to emerge as the preferred neoadjuvant therapy option for patients diagnosed with LAGC.

Immune checkpoint inhibitors for patients with mismatch-repair deficient or microsatellite instability-high advanced cancers: a meta-analysis of phase I-III clinical trials

BACKGROUND

Mismatch-repair deficient (dMMR) and microsatellite instability-high (MSI-H) cancers are associated with an increased number of somatic mutations, which can render tumors more susceptible to immune checkpoint blockade. However, a comprehensive evaluation of the efficacy profile of immune checkpoint inhibitors in this patient population across multiple cancer types is lacking. This study aims to address this knowledge gap by synthesizing data from Phase I-III clinical trials.

METHODS

A systematic search was conducted in PubMed, Embase, the Cochrane Central Register of Controlled Trials and Google Scholar from inception until June, 2024. Eligible studies included randomized controlled trials (RCTs), non-randomized comparative studies, and single-arm trials investigating immune checkpoint inhibitors in patients with dMMR/MSI-H advanced cancers. The primary outcome was objective response rate (ORR), and the secondary outcomes included disease control rate (DCR), 1-year, 2-year, and 3-year overall survival (OS) and progression-free survival (PFS) rates. Subgroup analyses were conducted for the primary outcome stratified by major study characteristics.

RESULTS

Of the 10802 identified studies, 19 trials in 25 studies totaling 2052 participants met the inclusion criteria and were included in the meta-analysis. The pooled ORR was 41.7% (95% CI, 35.7%-47.7%). The pooled DCR was 68.9% (95% CI, 62.2%-75.7%). The pooled 12-month, 24-month and 36-month OS rates were 29.1% (95% CI, 19.9%-38.3%), 35.8% (95% CI, 23.6%-48.0%), and 35.8% (95% CI, 23.6%-48.0%), respectively. The pooled 12-month, 24-month and 36-month PFS rates were 46.4% (95% CI, 39.1%-53.8%), 67.0% (95% CI, 55.2%-78.8%), and 63.1% (95% CI, 37.3%-88.9%), respectively.

CONCLUSIONS

The study establishes the therapeutic potential of immune checkpoint inhibitors in dMMR/MSI-H advanced cancers, highlighting the importance of MSI status in this context. Further head-to-head comparisons are needed to conclusively determine MSI's predictive power relative to proficient mismatch-repair/ microsatellite stable (pMMR/MSS) tumors.

Prognostic value of inflammatory markers NLR, PLR, and LMR in gastric cancer patients treated with immune checkpoint inhibitors: a meta-analysis and systematic review

Background

Immune checkpoint inhibitors (ICIs) represent a groundbreaking approach to cancer therapy. Inflammatory markers such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) have emerged as potential indicators strongly associated with tumor prognosis, albeit their prognostic significance remains contentious. The predictive value of NLR, PLR, LMR in patients with gastric cancer (GC) treated with ICIs has not been fully explored; therefore, we conducted a meta-analysis to examine the potential of inflammatory markers NLR, PLR, and LMR as survival predictors in this population.

Methods

A comprehensive search was conducted across PubMed, Embase, Web of Science, and Cochrane databases, with the search cut-off date set as March 2024. Hazard ratios (HR) and their corresponding 95% confidence intervals (CI) were calculated to assess the prognostic significance of NLR, PLR, and LMR for both progression-free survival (PFS) and overall survival (OS).

Results

Fifteen cohort studies involving 1336 gastric cancer patients were finally included in this meta-analysis. The results of the meta-analysis showed that high levels of NLR were associated with poorer OS and PFS in GC patients receiving ICIs, with combined HRs of OS [HR=2.01, 95%CI (1.72,2.34), P<0.01], and PFS PFS[HR=1.59, 95%CI (1.37,1.86), P<0.01], respectively; high levels of PLR were associated with poorer OS and PFS, and the combined HR was OS [HR=1.57, 95%CI (1.25,1.96), P<0.01], PFS [HR=1.52,95%CI (1.20, 1.94), P<0.01], respectively; and there was an association between elevated LMR and prolonged OS and PFS, and the combined HR was OS [HR=0.62, 95%CI (0.47,0.81), P<0.01], and PFS [HR=0.69, 95%CI (0.50,0.95), P<0.01].

Conclusion

In gastric cancer (GC) patients treated with immune checkpoint inhibitors (ICIs), elevated neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were associated with poorer overall survival (OS) and progression-free survival (PFS), while high lymphocyte-to-monocyte ratio (LMR) was linked to improved OS and PFS. Subgroup analyses suggested that NLR might be particularly pertinent to the prognosis of GC patients. In conclusion, the inflammatory markers NLR, PLR, and LMR serve as effective biomarkers for prognostic assessment in GC patients, offering valuable insights for therapeutic decision-making in the realm of GC immunotherapy. Prospective studies of high quality are eagerly awaited to validate these findings in the future.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier CRD42024524321.

Treatment patterns and survival outcomes of patients admitted to the intensive care unit due to immune-related adverse events of immune checkpoint inhibitors

INTRODUCTION

Severe immune-related adverse events (irAEs) due to immune checkpoint inhibitors (ICIs) can lead to admission to the intensive care unit (ICU). In this retrospective study, we determined the incidence, treatment patterns and survival outcomes of this patient population at a comprehensive cancer center.

METHODS

All patients admitted to the ICU due to irAEs from ICI treatment between January 2015 and July 2022 were included. Descriptive statistics were reported on patient characteristics and treatment patterns during hospital admission. Overall survival (OS) from the time of ICU discharge to death was estimated using the Kaplan-Meier method.

RESULTS

Over the study period, 5561 patients received at least one ICI administration, of which 32 patients (0.6%) were admitted to the ICU due to irAEs. Twenty patients were treated with anti-PD-1 plus anti-CTLA-4 treatment, whereas 12 patients were treated with ICI monotherapy. The type of irAEs were de novo diabetes-related ketoacidosis (n = 8), immune-related gastrointestinal toxicity (n = 8), myocarditis or myositis (n = 10), nephritis (n = 3), pneumonitis (n = 2), and myelitis (n = 1). The median duration of ICU admission was 3 days (interquartile range: 2-6 days). Three patients died during ICU admission. The median OS of the patients who were discharged from the ICU was 18 months (95% confidence interval, 5.0-NA).

CONCLUSION

The incidence of irAEs leading to ICU admission in patients treated with ICI was low in this study. ICU mortality due to irAEs was low and a subset of this patient population even had long-term survival.

Immunotherapy in the neoadjuvant treatment of gastrointestinal tumors: is the time ripe?

Immune checkpoint inhibitors (ICIs) revolutionized the management of mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) gastrointestinal (GI) cancers. Based on notable results observed in the metastatic setting, several clinical trials investigated ICIs as neoadjuvant treatment (NAT) for localized dMMR/MSI-H GI cancers, achieving striking results in terms of clinical and pathological responses and creating the opportunity to spare patients from neoadjuvant chemotherapy and/or radiotherapy and even surgical resection. Nevertheless, these impressive findings are mainly derived from small proof of concept phase II studies and there are still several open questions to address. Moreover, dMMR/MSI-H represents a limited subgroup accounting for less than 10% of GI cancers. Consequently, many efforts have been produced to investigate neoadjuvant ICIs also in mismatch repair-proficient/microsatellite stable (MSS) cancers, considering the potential synergistic effect in combining immune-targeted agents with standard therapies such as chemo and/or radiotherapy. However, results for combining ICIs to the standard of care in the unselected population are still unsatisfactory, without improvements in event-free survival in esophago-gastric adenocarcinoma for the addition of pembrolizumab to chemotherapy, and sometimes limited benefit in patients with locally advanced rectal cancer. Therefore, a major challenge will be to identify among the heterogenous spectrum of this disease, those patients that could take advantage of neoadjuvant immunotherapy and deliver the most effective treatment. In this review we discuss the rationale of NAT in GI malignancies, summarize the available evidence regarding the completed trials that evaluated this treatment strategy in both MSI-H and MSS tumors. Finally, we discuss ongoing studies and future perspectives to render neoadjuvant immunotherapy another arrow in the quiver for the treatment of locally advanced GI tumors.

Neoadjuvant Immunotherapy Effectiveness in Patients With Microsatellite Instability-High (MSI-H) Gastric Cancer

Purpose This research work evaluates monotherapy with checkpoint inhibitors (CPI). as a neoadjuvant treatment for patients with Microsatellite Instability-High (MSI-H) locally advanced gastric cancer. Methods Here we present the results of the retrospective study from Napalkov Cancer Center over 4.5 years on patients with MSI-H locally advanced gastric cancer. A total of 566 patients were analyzed, 18 of whom were included in the research, focusing on clinical response rate, surgical pathology, 'watch and wait' strategy, and safety outcomes on an exploratory basis. Patients were assigned to four to eight neoadjuvant cycles of CPI, followed by surgery. Results The objective response to neoadjuvant CPI in patients with MSI-H gastric cancer was 77.8%. Complete response was achieved in five (27.8%) and partial response in nine (50%) patients, accordingly. Surgery was performed on 14 patients. Complete margin-free (R0) resection rates were 100%. Downstaging was observed in 12 out of 14 patients. Histopathologic complete response rates (pathologic complete response or Tumor Regression Grade-major response (TRG1)) were achieved in eight (57.1%) patients. No disease progression was detected with a median follow-up of 33.7 months (4.4-55.7 months). Clinically significant adverse events were not observed. Conclusion CPI in a neoadjuvant setting for patients with MSI-H locally advanced gastric cancer is highly effective and safe.

Adjuvant and neoadjuvant chemotherapy for MSI early gastric cancer: a systematic review and meta-analysis

Background

Perioperative chemotherapy (CT) is an established therapeutic approach for patients diagnosed with stage IB-III gastric cancer (GC).

Objectives

This study aimed to investigate the efficacy of this approach in individuals with GC exhibiting high microsatellite instability (MSI-H).

Design

A systematic review was conducted, including studies that provided data on (neo)adjuvant CT outcomes in patients with MSI-H GC.

Methods

Systematic searches were conducted in PubMed, Cochrane Central of Controlled Trials, and Embase databases. Data were aggregated using hazard ratios (HRs) to compare overall survival between CT and surgery.

Results

Data analysis from 23 studies, including 22,011 patients, revealed that the prevalence of MSI-H is 9.8%. Administration of adjuvant or perioperative CT did not significantly reduce the risk of death or relapse in patients with MSI-H GC (HR = 0.8, 95% CI 0.54-1.16; p = 0.24 and HR = 0.84, 95% CI 0.59-1.18; p = 0.31, respectively).

Conclusion

Chemotherapy did not benefit patients diagnosed with MSI-H nonmetastatic GC but rather will be integrated with immune checkpoint inhibitors in the near future.

Safety and feasibility of minimally invasive gastrectomy after neoadjuvant immunotherapy for locally advanced gastric cancer: a propensity score-matched analysis in China

Background

The effect of neoadjuvant immunotherapy on minimally invasive gastrectomy (MIG) for locally advanced gastric cancer (LAGC) remains controversial. This study aimed to compare short-term outcomes between MIG after neoadjuvant chemo-immunotherapy (NICT-MIG) and MIG after neoadjuvant chemotherapy alone (NCT-MIG), and determine risk factors for post-operative complications (POCs).

Methods

This retrospective study included clinicopathologic data from 193 patients who underwent NCT-MIG or NICT-MIG between January 2020 and February 2023 in the Department of General Surgery, Chinese People's Liberation Army General Hospital First Medical Center (Beijing, China). Propensity score-matched analysis at a ratio of 1:2 was performed to reduce bias from confounding patient-related variables and short-term outcomes were compared between the two groups.

Results

The baseline characteristics were comparable between 49 patients in the NICT-MIG group and 86 patients in the NCT-MIG group after propensity score matching. Objective and pathologic complete response rates were significantly higher in the NICT-MIG group than in the NCT-MIG group (P < 0.05). The overall incidence of treat-related adverse events, intraoperative bleeding, operation time, number of retrieved lymph nodes, time to the first flatus, post-operative duration of hospitalization, overall morbidity, and severe morbidity were comparable between the NCT-MIG and NICT-MIG groups (P > 0.05). By multivariate logistic analysis, estimated blood loss of >200 mL (P = 0.010) and prognostic nutritional index (PNI) score of <45 (P = 0.003) were independent risk factors for POCs after MIG following neoadjuvant therapy.

Conclusions

Safety and feasibility of NICT were comparable to those of NCT in patients undergoing MIG for LAGC. Patients with an estimated blood loss of >200 mL or a PNI score of <45 should be carefully evaluated for increased POCs risk.

Neoadjuvant Immunotherapy for Patients with dMMR/MSI-High Gastrointestinal Cancers: A Changing Paradigm

Immune checkpoint inhibitors have revolutionized the management of mismatch repair-deficient (MMR-D)/microsatellite instability-high (MSI-H) gastrointestinal cancers, particularly colorectal cancer. Cancers with the MMR-D/MSI-H genotype often carry a higher tumor mutation burden with frameshift alterations, leading to increased mutation-associated neoantigen (MANA) generation. The dramatic response seen with immune checkpoint inhibitors (ICIs), which are orchestrated by MANA-primed effector T cells, resulted in the rapid development of these novel therapeutics within the landscape of MSI-H gastrointestinal cancers. Recently, several clinical trials have utilized ICIs as potential neoadjuvant therapies for MSI-H gastrointestinal cancers and demonstrated deep clinical and pathological responses, creating opportunities for organ preservation. However, there are potential challenges to the neoadjuvant use of ICIs for certain disease types due to the clinical risk of overtreatment for a disease that can be cured through a surgery-only approach. In this review article, we discuss neoadjuvant management approaches with ICI therapy for patients with MSI-H gastrointestinal cancers, including those with oligometastatic disease. We also elaborate on potential challenges and opportunities for the neoadjuvant utilization of ICIs and provide further insight into the changing treatment paradigm of MMR-D/MSI-H gastrointestinal cancers.