Meta-analysis of neoadjuvant immunotherapy for non-metastatic colorectal cancer

Current and future perspectives in the management and treatment of colorectal cancer

In this editorial, we reviewed the article by Fadlallah et al that was recently published in the World Journal of Clinical Oncology. The article provided a comprehensive and in-depth view of the management and treatment of colorectal cancer (CRC), one of the leading causes of cancer-related morbidity and mortality worldwide. The article analyzed the therapeutic modalities and their sequencing, focusing on total neoadjuvant therapy for locally advanced rectal cancer. It highlighted the role of immunotherapy in tumors with high microsatellite instability or deficient mismatch repair, addressing recent advances that have improved prognosis and therapeutic response in localized and metastatic CRC. Innovations in surgical techniques, advanced radiotherapy, and systemic agents targeting specific mutational profiles are also discussed, reflecting on how they revolutionized clinical management. Circulating tumor DNA has emerged as a promising tool for detecting minimal residual disease, prognosis, and therapeutic monitoring, solidifying its role in precision oncology. This review emphasized the importance of technological and therapeutic advancements in improving clinical outcomes and personalizing CRC treatment.

A management of patients achieving clinical complete response after neoadjuvant therapy and perspectives: on locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME) and selective use of adjuvant chemotherapy is currently considered the standard of care for locally advanced rectal cancer (LARC). Despite this, the concept of organ preservation is gradually challenging this approach. The management of complete clinical remission (cCR) lacks international consensus, leading scholars to develop their own perspectives based on well-designed studies and long-term data from large multicenter cohorts. To ensure appropriate treatment, this review focuses on the choice of neoadjuvant therapy, criteria for defining cCR, and treatment strategies for patients who achieve cCR after neoadjuvant therapy. By providing guidance on the accurate management of LARC patients after cCR, this review aims to prevent over- or under-treatment.

Impact of exercise type, duration, and intensity on depressive symptoms in older adults: a systematic review and meta-analysis

Objective

This systematic review and meta-analysis assessed the effects of three types of physical exercise (resistance exercise, aerobic exercise, and group exercise), different exercise intervention times (3 months, 6 months), and different exercise intensities (low, moderate, and high) on the improvement of depressive symptoms in older adults aged ≥60 years, as well as to explore the impact of the sustainability of these physical exercise intervention programs on depressive symptoms in older adults.

Methods

The randomized controlled trials (RCTs) on the effect of physical exercise on depressive symptoms in older adults were retrieved from Cochrane Library, Web of Science, PubMed, and Embase Data. The retrieval time limit is from establishing the database to January 7, 2024. We conducted a meta-analysis using a 95% confidence interval (95% CI) and the standardized mean differences (SMD). The I2 statistic was used to assess the heterogeneity of the outcomes of the studies. When I 2 < 50%, we used the fixed-effects model, and when I 2 > 50%, we used the random-effects model. Subgroup and sensitivity analyses investigated heterogeneity origins.

Results

There are 15 articles reported 20 studies, with a total of 1,346 patients, including 689 in the control group and 657 in the experimental group. The findings demonstrated a notable improvement in depression symptoms among older persons as an immediate result of engaging in physical exercise [SMD = -0.82, 95% CI (-1.19, -0.45)]. The subgroup analysis showed that moderate-intensity physical exercise [SMD = -0.25, 95% CI (-0.47, -0.03)], high-intensity physical exercise [SMD = -0.94, 95% CI (-1.37, -0.51)], resistance exercise [SMD = -0.70, 95% CI (-1.20, -0.20)], and group exercise [SMD = -0.97, 95% CI (-1.89, -0.05)], and the exercise intervention time was 3 months [SMD = -0.81, 95% CI (-1.38, -0.23)] or 6 months [SMD = -0.93, 95% CI (-1.46, -0.41)] were more effective in improving depressive symptoms in older adults.

Conclusion

The sustainable resistance and group exercise have a better effect on improving depressive symptoms in older adults. Appropriate exercise intervention time can also ensure the sustainable improvement effect of exercise.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/record_email.php, identifier CRD42023405525.

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.

Establishment of a chemokine-based prognostic model and identification of CXCL10+ M1 macrophages as predictors of neoadjuvant therapy efficacy in colorectal cancer

Background

Although neoadjuvant therapy has brought numerous benefits to patients, not all patients can benefit from it. Chemokines play a crucial role in the tumor microenvironment and are closely associated with the prognosis and treatment of colorectal cancer. Therefore, constructing a prognostic model based on chemokines will help risk stratification and providing a reference for the personalized treatment.

Methods

Employing LASSO-Cox predictive modeling, a chemokine-based prognostic model was formulated, harnessing the data from TCGA and GEO databases. Then, our exploration focused on the correlation between the chemokine signature and elements such as the immune landscape, somatic mutations, copy number variations, and drug sensitivity. CXCL10+M1 macrophages identified via scRNA-seq. Monocle2 showed cell pseudotime trajectories, CellChat characterized intercellular communication. CytoTRACE analyzed neoadjuvant therapy stemness, SCENIC detected cell type-specific regulation. Lastly, validation was performed through multiplex immunofluorescence experiments.

Results

A model based on 15 chemokines was constructed and validated. High-risk scores correlated with poorer prognosis and advanced TNM and clinical stages. Individuals presenting elevated risk scores demonstrated an increased propensity towards the development of chemotherapy resistance. Subsequent scRNA-seq data analysis indicated that patients with higher presence of CXCL10+ M1 macrophages in tumor tissues are more likely to benefit from neoadjuvant therapy.

Conclusion

We developed a chemokine-based prognostic model by integrating both single-cell and bulk RNA-seq data. Furthermore, we revealed epithelial cell heterogeneity in neoadjuvant outcomes and identified CXCL10+ M1 macrophages as potential therapy response predictors. These findings could significantly contribute to risk stratification and serve as a key guide for the advancement of personalized therapeutic approaches.

Neoadjuvant immunotherapy leads to complete pathologic response in locally advanced colon cancer

Immunotherapy is considered first line in patients with dMMR metastatic colorectal cancer (CRC). Recent studies have also shown promising results with neoadjuvant immunotherapy in locally advanced CRC. We report a case in which neoadjuvant immunotherapy with pembrolizumab resulted in complete pathologic response at time of resection as well as saved the patient the morbidity associated with a hepatectomy. We also completed a scoping review of the literature which suggests promising tumor responses with treatment in dMMR CRC. Further randomized control trials to determine the magnitude of response and optimal regimen are needed.

Systematic Review of Neoadjuvant Immunotherapy for Mismatch Repair Deficient Locally Advanced Colon Cancer: An Emerging Strategy

BACKGROUND

In April 2023, the National Comprehensive Cancer Network endorsed neoadjuvant immunotherapy for select patients with nonmetastatic mismatch repair deficient colon cancer. Approximately 15% of incident colon cancers are mismatch repair deficient, resulting in a distinct molecular subtype with high microsatellite instability that is responsive to immune checkpoint inhibition.

OBJECTIVE

To describe the existing evidence supporting neoadjuvant immunotherapy for mismatch repair deficient, microsatellite unstable nonmetastatic colon cancer.

DATA SOURCES

A medical librarian performed PubMed, Embase, and Web of Science searches most recently on April 24, 2023. The PubMed search was re-run on September 26, 2023, to identify any additional studies published between April 24 and September 26, 2023.

STUDY SELECTION

Two authors screened titles and abstracts in the published studies. The inclusion criteria were 1) English language, 2) adults with primary cancer of the colon, 3) nonmetastatic disease, 4) neoadjuvant immunotherapy, and 5) reporting on 10 or more cases.

INTERVENTION

Neoadjuvant immunotherapy.

MAIN OUTCOME MEASURES

Safety (grade 3+ treatment-related adverse events) and efficacy (complete pathologic responses).

RESULTS

From 7691 studies identified, 6370 were screened and 8 were included. Various agents, dosing regimens, and treatment durations were used, with durations of immunotherapy ranging from 1 to 16 cycles. Complete R0 resections were consistently achieved in 98% to 100% of resections. Of patients who received neoadjuvant immunotherapy and underwent resection, 50% to 91% had ypT0N0 pathology. The safety profiles were generally favorable, with grade 1 to 2 treatment-related adverse events (mostly immune-related) during immunotherapy reported in 22.2% to 70% of patients. Postoperative complications after neoadjuvant immunotherapy were reassuring, with no severe complications reported.

LIMITATIONS

Small number of heterogeneous and uncontrolled studies precluding a meta-analysis.

CONCLUSIONS

Neoadjuvant immune checkpoint inhibition is associated with high rates of pathologic complete responses in locally advanced colon cancer. The literature is limited, particularly for postoperative outcomes, and more studies are needed to understand the safety and positioning of these regimens in the neoadjuvant context.

Neoadjuvant immunotherapy based on PD-1/L1 inhibitors for gastrointestinal tumors: a review of the rationale and clinical advances

The landscape of current tumor treatment has been revolutionized by the advent of immunotherapy based on PD-1/PD-L1 inhibitors. Leveraging its capacity to mobilize systemic antitumor immunity, which is primarily mediated by T cells, there is growing exploration and expansion of its potential value in various stages of clinical tumor treatment. Neoadjuvant immunotherapy induces a robust immune response against tumors prior to surgery, effectively facilitating tumor volume reduction, early eradication or suppression of tumor cell activity, and control of potential metastatic spread, to improve curative surgical resection rates, and prevent tumor recurrence. This review delineates the theoretical basis of neoadjuvant immunotherapy from preclinical research evidence, discusses specific challenges in clinical application, and provides a comprehensive overview of clinical research progress in neoadjuvant immunotherapy for gastrointestinal tumors. These findings suggest that neoadjuvant immunotherapy has the potential to ameliorate immunosuppressive states and enhance cytotoxic T cell function while preserving lymphatic drainage in the preoperative period. However, further investigations are needed on specific treatment regimens, suitable patient populations, and measurable endpoints. Despite numerous studies demonstrating the promising efficacy and manageable adverse events of neoadjuvant immunotherapy in gastrointestinal tumors, the availability of high-quality randomized controlled trials is limited, which highlights the necessity for further research.

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.

Evolution of therapy for locally advanced rectal cancer

Rectal cancer is a prevalent disease worldwide. The standard treatment of locally advanced rectal cancer (LARC) is preoperative chemoradiotherapy followed by surgery and adjuvant systemic chemotherapy. Studies have been done to determine the best sequence of treatments to improve survival, cure rate and long term toxicity profile. In this paper, we will review the literature regarding the evolution of LARC treatment.

Immunotherapy for Colorectal Cancer with High Microsatellite Instability: The Ongoing Search for Biomarkers

Microsatellite instability (MSI) is a biological condition associated with inflamed tumors, high tumor mutational burden (TMB), and responses to immune checkpoint inhibitors. In colorectal cancer (CRC), MSI tumors are found in 5% of patients in the metastatic setting and 15% in early-stage disease. Following the impressive clinical activity of immune checkpoint inhibitors in the metastatic setting, associated with deep and long-lasting responses, the development of immune checkpoint inhibitors has expanded to early-stage disease. Several phase II trials have demonstrated a high rate of pathological complete responses, with some patients even spared from surgery. However, in both settings, not all patients respond and some responses are short, emphasizing the importance of the ongoing search for accurate biomarkers. While various biomarkers of response have been evaluated in the context of MSI CRC, including B2M and JAK1/2 mutations, TMB, WNT pathway mutations, and Lynch syndrome, with mixed results, liver metastases have been associated with a lack of activity in such strategies. To improve patient selection and treatment outcomes, further research is required to identify additional biomarkers and refine existing ones. This will allow for the development of personalized treatment approaches and the integration of novel therapeutic strategies for MSI CRC patients with liver metastases.

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.