Efficacy and safety of neoadjuvant sintilimab in combination with FLOT chemotherapy in patients with HER2-negative locally advanced gastric or gastroesophageal junction adenocarcinoma: an investigator-initiated, single-arm, open-label, phase II study

Sequential dual-energy CT for longitudinal assessment of pathologic response to neoadjuvant immuno-chemotherapy in locally advanced gastric cancer

OBJECTIVES

To longitudinally evaluate pathologic response outcomes after neoadjuvant immuno-chemotherapy (NICT) for patients with locally advanced gastric cancer (LAGC) using pre- and post-treatment dual-energy CT (DECT).

MATERIALS AND METHODS

Between Jan 2021 and Dec 2023, 115 patients who underwent NICT plus gastrectomy and triple-phase enhanced DECT scans before and after NICT were retrospectively enrolled. Pathologic tumor regression grade (TRG) was the reference standard, patients were labelled as responders (TRG = 0 + 1) and non-responders (TRG = 2 + 3) accordingly. A two-dimensional free-hand region of interest method was adopted to obtain the iodine concentration (IC) values. Pre- and post-NICT IC and normalized IC (nIC) were measured at arterial/venous/delay phase (AP/VP/DP), respectively; their changes [ΔIC (%)] defined as (IC_post-IC_pre)⁄IC_pre × 100% were calculated. Pre- and post-NICT imaging parameters and their changes were compared between different response groups. Non-responders' associated parameters were selected using multivariable logistic regression analysis. Their performances were analyzed by the area under the receiver operating characteristic curve (AUC). Their associations with patient survival were explored by using Kaplan-Meier survival analysis.

RESULTS

ICDP-pre, ΔICAP, thickness-post with cut-off value of > 2.306 mg/mL, ≤ 26.70%, > 18.5 mm, respectively, indicates non-responders with equivalent AUC being 0.616 (95% CI: 0.521-0.705), 0.625 (95% CI: 0.529-0.713), and 0.660 (95% CI: 0.565-0.745). Their combination demonstrated an improved AUC of 0.774 (95% CI: 0.686-0.846) and was associated with patient disease-free survival (DFS) with a hazard ratio being 2.239 (95% CI: 1.004-4.991) (p = 0.026).

CONCLUSION

Pre- and post-NICT DECT-based quantifications are useful for longitudinal assessment of pathologic response outcomes after NICT in LAGC. ICDP-pre, ΔICAP, and thickness-post are equally useful, their combination demonstrated incremental benefit.

KEY POINTS

Question Accurate evaluation of the efficacy of NICT in patients with LAGC remains challenging due to the lack of effective biomarkers. Findings Sequential DECT-based ICDP-pre, ΔICAP, and tumor thickness-post were predictive of TRG status. Their combination demonstrated enhanced performance and was associated with patient DFS. Clinical relevance DECT represents a promising imaging technique with added advantages for longitudinal assessment of pathologic response to NICT in LAGC, potentially facilitating more personalized treatment strategies among this population.

Phase 2 trial of perioperative chemo-immunotherapy for gastro-esophageal adenocarcinoma: The role of M2 macrophage landscape in predicting response

We present the clinical results of a phase 2 trial combining neoadjuvant docetaxel, cisplatin, 5 Flourouracil, and the PD-L1 inhibitor avelumab in locally advanced gastro-esophageal adenocarcinoma (GEA). Fifty-one patients receive neoadjuvant therapy with 50 proceeding to surgery. Grade 3-4 adverse events occur in 40%; complete/major pathological response is found in 7/50 (14%) and 9/50 (18%), with 2-year disease-free survival of 67.5%. There is no correlation between tumor regression and PD-L1 or mismatch repair (MMR) status. Multiplex immunohistochemistry and longitudinal single-cell transcriptomic profiling reveal alterations in certain innate immune cell populations, particularly noting an M2-tumor-associated macrophage (M2-TAM) proliferation in non-responding tumors. These findings describe the effective nature of this treatment regimen for GEA and reveal associated features of the inflammatory milieux associated with response to chemo-immunotherapy. The specific character of the inflammatory environment in non-responders may, in the future, help personalize treatment. This study was registered at ClinicalTrials.gov (NCT03288350).

Potential predictive value of CD8A and PGF protein expression in gastric cancer patients treated with neoadjuvant immunotherapy

BACKGROUND

Immunoneoadjuvant therapy has gained significant attention due to its remarkable advancements in cancer treatment. This study aimed to investigate the molecular mechanisms underlying immunoneoadjuvant therapy through a comprehensive multiomics analysis of samples from a registered clinical trial cohort.

METHODS

Preoperative samples were collected from 16 patients, and postoperative samples were obtained from 12 among them. RNA sequencing (RNA-seq) and Olink proteomics were employed to identify key genes before and after neoadjuvant treatment. The weighted coexpression network was constructed using Weighted gene co-expression network analysis (WGCNA). Furthermore, the proportion of infiltrated immune cells was calculated using xCell based on normalized expression data derived from RNA-seq.

RESULTS

Patients were stratified into T1 (good efficacy) and T2 (poor efficacy) groups based on Tumor Regression Grade (TRG) to neoadjuvant immunotherapy. Compared to the T2 group (TRG2 and TRG3), the T1 group (TRG0 and TRG1) showed significant differences in pathways related to inflammatory response and myeloid leukocyte activation. Furthermore, the T1 group exhibited elevated levels of CD8+ T cells and B cells. The top two factors with the highest area under the Receiver Operating Characteristic (ROC) curve were CD8a molecule (CD8A) (1.000) and C-C motif chemokine ligand 20 (CCL20) (0.967). Additionally, the expression of placenta growth factor (PGF) and TNF receptor superfamily member 21 (TNFRSF21) proteins significantly increased in the T1 group compared to the T2 group. High expression of CD8A and PGF were associated with favorable and poor prognosis in gastric cancer patients, respectively. Immunoinfiltration analysis revealed a positive correlation between CD8A and dendritic cell (DC) levels, while a negative correlation was observed with myeloid-derived suppressor cell (MDSC) levels.

CONCLUSIONS

Through multiomics analysis, we discovered that CD8A is linked to enhanced treatment response and tumor regression. In contrast, PGF appears to exert adverse effects on treatment outcomes, suggesting a complex interplay of factors influencing the efficacy of immunoneoadjuvant therapy in gastric cancer.

Prospects for the application of pathological response rate in neoadjuvant therapy for gastric cancer

With the annual increase in the incidence and mortality rates of gastric cancer, it has gradually become one of the significant threats to human health. Approximately 90% of gastric cancer patients are diagnosed with adenocarcinoma. Although the 5-year survival rate for early-stage gastric cancer can exceed 90%, due to its concealed symptoms, less than half of the patients are eligible for radical surgical treatment upon diagnosis. For gastric cancer patients receiving palliative treatment, the current expected survival time is only about one year. In China, the majority of gastric cancer patients, accounting for about 80% of the total, are in the locally advanced stage. For these patients, radical surgery remains the primary treatment option; however, surgery alone is often inadequate in controlling tumor progression. In the pivotal MAGIC study, the recurrence rate was as high as 75%, and similar results were obtained in the French ACCORD07-FFCD9703 study. Numerous clinical trials are currently exploring preoperative neoadjuvant therapy for patients with locally advanced gastric cancer. Data indicates that preoperative neoadjuvant therapy can not only reduce the size of the local tumor but also shrink surrounding lymph nodes, thereby downstaging the tumor and improving the R0 resection rate. Additionally, it can decrease tumor cell activity and eliminate potential micrometastases. The emergence of various immunotherapies has ushered in a new era for neoadjuvant treatment options for gastric cancer.

How do I treat dMMR/MSI gastro-oesophageal adenocarcinoma in 2025? A position paper from the EORTC-GITCG gastro-esophageal task force

In less than a decade, immune checkpoint inhibitors (ICIs) have transformed the management of mismatch repair-deficient (dMMR) and microsatellite instability-high (MSI) cancers. However, beyond colorectal cancer (CRC), much of the evidence is mostly derived from non-randomized phase II studies or post-hoc analyses of broader clinical trials. dMMR/MSI tumours represent a specific subgroup of gastro-esophageal adenocarcinomas (GEA), accounting for approximately 9 % of cases, with a higher prevalence in early-stage compared to advanced-stage disease and older female patients. These tumours are predominantly sporadic, often linked to MLH1 promoter methylation, and rarely exhibit HER2 overexpression/ERBB2 amplification or other oncogenic drivers. The treatment landscape for early stage dMMR/MSI GEA is likely to change substantially soon, as ICIs have shown high pathological complete response (pCR) rates in small phase II trials, raising questions on optimisation of neoadjuvant therapy, and paving the way for organ preservation. The standard of treatment for untreated patients with advanced dMMR/MSI GEA is chemotherapy + ICI irrespectively of PDL-1 status. However, the role of chemotherapy-free regimen consisting of CTLA-4 plus PD-1 inhibitors remains undetermined. This review addresses these and other emerging questions, offering expert opinions and insights into the future therapeutic landscape for dMMR/MSI GEA.

Association of Body Composition Parameters with the Short- and Long-Term Efficacy of Neoadjuvant Immunotherapy Combined with Chemotherapy in Advanced Gastric Cancer

BACKGROUND

Immunotherapy has become a prevalent strategy in the neoadjuvant treatment of advanced gastric cancer (AGC). This study investigates the predictive value of computed tomography (CT)-derived body composition parameters on the efficacy of neoadjuvant immunotherapy for AGC.

METHODS

Data on 103 patients with resectable AGC who received neoadjuvant immunotherapy combined with chemotherapy at a teaching hospital between March 2020 and August 2022 were collected. Body composition parameters, including the subcutaneous adipose index (SAI), visceral adipose index (VAI), and skeletal muscle index (SMI), were calculated from pretreatment CT images. Logistic regression and Cox proportional hazards models assessed the impact of these parameters on pathological responses and survival outcomes following treatment.

RESULTS

Of the patients, 34 (33.0%) achieved a major pathological response (MPR). Higher SAI, VAI, and SMI values were significantly linked to an increased likelihood of achieving MPR (p < 0.05). Multivariate regression analysis revealed that only SAI independently predicted MPR (OR 1.042, 95% CI 1.009-1.077, p = 0.013). Furthermore, patients with a high SAI had significantly improved 2-year overall survival (76.9% vs. 54.9%, log-rank p = 0.012) and 2-year event-free survival (71.2% vs. 51.0%, log-rank p = 0.022) compared to those with low SAI. The survival benefit associated with high SAI was partly due to its higher MPR rate (mediating proportion: 37.5%, 95% CI: 12%-110%).

CONCLUSION

Pretreatment SAI independently correlates with MPR and better oncological outcomes in patients with AGC receiving neoadjuvant immunotherapy.

Study on the therapeutic effect of sintilimab combined with modified DCF regimen on advanced gastric cancer and its impact on Th1/Th2 immune balance

The aim of this study was to observe the therapeutic effect of sintilimab combined with a modified docetaxel + cisplatin + fluorouracil (DCF) regimen on advanced gastric cancer and its effect on Th1/Th2 immune balance. Ninety-eight cases of advanced gastric cancer patients who visited our hospital from April 2020 to May 2022 were selected and divided into 48 cases each in the conventional group and the research group by random number table method; the DCF regimen was adopted in the conventional group, and sintilimab combined with modified DCF regimen was adopted in the research group, and the therapeutic effects of the patients in the two groups and the changes of Th1/Th2 immune indexes were compared. CEA, CA199, CA242, CD168 AQ3, and IL-4 in the study group were lower than those in the conventional group at the end of three cycles of treatment, and the difference was statistically significant ( P  < 0.001). The levels of IFN-γ and IL-4 in the study group at the end of three cycles of treatment were higher than those in the conventional group ( P  < 0.001). The incidence of adverse reactions during treatment in the study group was lower than that in the conventional group ( P  < 0.001), and the grading of adverse reactions in the study group was milder than that in the conventional group. Sintilimab combined with a modified DCF regimen in the treatment of advanced gastric cancer not only improves the therapeutic effect but also positively affects the Th1/Th2 immune balance, which provides better immune regulation for patients with advanced gastric cancer.

Tumor-associated macrophage clusters linked to immunotherapy in a pan-cancer census

Transcriptional heterogeneity of tumor-associated macrophages (TAMs) has been investigated in individual cancers, but the extent to which these states transcend tumor types and represent a general feature of cancer remains unclear. We performed pan-cancer single-cell RNA sequencing analysis across nine cancer types and identified distinct monocyte/TAM composition patterns. Using spatial analysis from clinical study tissues, we assessed TAM functions in shaping the tumor microenvironment (TME) and influencing immunotherapy. Two specific TAM clusters (pro-inflammatory and pro-tumor) and four TME subtypes showed distinct immunological features, genomic profiles, immunotherapy responses, and cancer prognosis. Pro-inflammatory TAMs resided in immune-enriched niches with exhausted CD8+ T cells, while pro-tumor TAMs were restricted to niches associated with a T-cell-excluded phenotype and hypoxia. We developed a machine learning model to predict immune checkpoint blockade response by integrating TAMs and clinical data. Our study comprehensively characterizes the common features of TAMs and highlights their interaction with the TME.

A prospective phase II clinical trial of total neoadjuvant therapy for locally advanced gastric cancer and gastroesophageal junction adenocarcinoma

To investigate the safety and efficacy of the neoadjuvant chemoradiotherapy (NCRT) followed by neoadjuvant consolidation chemotherapy (NCCT) and surgery for locally advanced gastric cancer (GC) or gastroesophageal junction (GEJ) adenocarcinoma. Patients diagnosed as locally advanced GC or Siewert II/III GEJ adenocarcinoma with clinical stage T3-4 and/or N positive were prospectively enrolled. Patients underwent NCRT (45 Gy/25 fractions) with concurrent S-1, followed by NCCT (4 to 6 cycles of the SOX regimen) 2 to 4 weeks after NCRT. Gastric cancer radical resection with D2 lymph node dissection was performed 4 to 6 weeks after the total neoadjuvant therapy. The study was conducted from November 2019 to January 2023, enrolling a total of 46 patients. During the NCRT, all patients completed the treatment without dose reduction or delay. During the NCCT, 32 patients (69.6%) completed at least 4 cycles of chemotherapy. Grade 3 or higher adverse events in NCRT (5 cases) were non-hematological. During the course of NCCT, a notable occurrence of hematological toxicities was observed, with grade 3 or higher leukopenia (9.7%) and thrombocytopenia (12.2%) being experienced. A total of 28 patients (60.9%) underwent surgery, achieving R0 resection in all cases. A significant proportion of cases (71.4%) exhibited pathological downstaging to ypT0-2, while 10 patients (35.7%) demonstrated a pathologic complete response (pCR). The total neoadjuvant therapy comprising NCRT followed by NCCT and surgery demonstrates a low severe adverse reactions and promising efficacy, which could be considered as a viable treatment for locally advanced GC or GEJ adenocarcinoma.Trial registration: Clinicaltrials.gov (registration number: NCT04062058); the full date of first trial registration was 20/08/2019.