Efficacy of intra-arterial chemotherapy with sequential anti-PD-1 antibody in unresectable gastric cancer: A retrospective real-world study

Quadruple therapy with immunotherapy and chemotherapy as first-line conversion treatment for unresectable advanced gastric adenocarcinoma: A case report

BACKGROUND

The treatment of gastric cancer remains highly challenging, particularly in cases of unresectable locally advanced or metastatic disease. Although chemotherapy and immunotherapy have shown some efficacy in such patients, significant limitations persist in extending survival and enhancing safety. To address these challenges, we designed an innovative first-line quadruple conversion therapy regimen that integrates a programmed cell death protein 1 (PD-1) inhibitor with chemotherapy, and we successfully implemented this therapy regimen in the treatment of a patient with unresectable locally advanced gastric adenocarcinoma.

CASE SUMMARY

We report the case of a 55-year-old male who was diagnosed with unresectable locally advanced gastric adenocarcinoma and presented with intermittent epigastric pain and multiple lymph node metastases in the abdominal cavity, with the metastasis being notably large in size. The tumor tissue was negative for human epidermal growth factor receptor 2 by immunohistochemistry. Considering the patient's status, the multidisciplinary team decided to administer sintilimab in combination with albumin-bound paclitaxel (nab-paclitaxel), S-1, and oxaliplatin as a quadruple drug conversion therapy. After 4 cycles of conversion therapy, the patient's epigastric pain was significantly alleviated, his stool color normalized, the volume of the primary tumor and lymph node metastases was markedly reduced, and the tumor marker levels decreased to within the normal range. The patient subsequently underwent laparoscopic total gastrectomy with abdominal lymph node dissection, and postoperative pathological biopsy revealed a pathological complete response and R0 resection, after which the patient recovered to an excellent physical status.

CONCLUSION

To the best of our knowledge, this is the first reported case of unresectable locally advanced gastric adenocarcinoma successfully treated with quadruple therapy with a PD-1 inhibitor and chemotherapy as a first-line conversion regimen. This first-line conversion therapy with the quadruple regimen may be effective and safe for unresectable locally advanced gastric adenocarcinoma.

Association of PD-1 + Treg/PD-1 + CD8 ratio and tertiary lymphoid structures with prognosis and response in advanced gastric cancer patients receiving preoperative treatment

BACKGROUND

Recent studies have highlighted the distinct ratio of PD-1 + Treg/PD-1 + CD8 for prognosis prediction. However, it remains unclear about the association of this ratio and tertiary lymphoid structures (TLS) with prognosis and response to neoadjuvant or conversion therapy in advanced gastric cancer.

METHODS

Firstly, fresh postoperative samples from 68 gastric cancer patients in Renji Hospital were collected. Meanwhile, immune cell infiltration as well as clinical prognosis analysis were conducted. Subsequently, we further systematically evaluated flow cytometry analysis of tumor samples and TLS expression in 38 gastric cancer patients with different response situations after neoadjuvant therapy. Also, a Renji conversion therapy cohort including 10 patients with complete matching samples before and after treatment was established to receive RNA sequencing analysis and multiplex immunohistochemistry (mIHC) tests. The corresponding TLS score and immune cell infiltration were further compared based on therapeutic response variations.

RESULTS

In general, the ratio of PD-1 + Treg/PD-1 + CD8>1 could be regarded as an independent predictor of prognosis in advanced gastric cancer patients. Moreover, PD-1 + Treg/PD-1 + CD8 < 1 and high expression of TLS could indicate better neoadjuvant therapy response and extended survival time in advanved gastric cancer patients. Besides, PD-1 + Treg/PD-1 + CD8 low &TLS high group could predict better progression free survival time (PFS) in complete response (CR) subgroup. In response group after conversion therapy, the number of PD-1 + CD8 + T cells significantly increased, mainly occurring outside the TLSs. Meanwhile, the TLSs were also considerably activated as we could observed.

CONCLUSIONS

This study underlined that combining PD-1 + Treg/PD-1 + CD8 ratio and TLS were significantly associated with prognosis and preoperative treatment response in advanced gastric cancer. Inspiringly, these indicators have the potential to elucidate the immune balance of advanced gastric cancer patients and can accurately guide subsequent therapeutic strategies.

Tertiary lymphoid structures as potential biomarkers for cancer prediction and prognosis

Tertiary lymphoid structures (TLSs) are ectopic lymphocyte aggregates formed in non-lymphoid tissues, including cancers, and are loci for the generation of in situ anti-tumor immune responses, which play a crucial role in cancer control. The state of TLS presence in cancer and its composition can significantly impact the treatment response and prognosis of patients. TLSs have the potential to serve as predictive and prognostic biomarkers for cancer. However, the mechanisms underlying TLS formation in cancer and how the essential components of TLSs affect cancer are not fully understood. In this review, we summarized TLS formation in cancer, the value of the TLS in different states of existence, and its key constituents for cancer prediction and prognosis. Finally, we discussed the impact of cancer treatment on TLSs.

Macrophages and tertiary lymphoid structures as indicators of prognosis and therapeutic response in cancer patients

Tertiary lymphoid structures (TLS) can reflect cancer prognosis and clinical outcomes in various tumour tissues. Tumour-associated macrophages (TAMs) are indispensable components of the tumour microenvironment and play crucial roles in tumour development and immunotherapy. TAMs are associated with TLS induction via the modulation of the T cell response, which is a major component of the TLS. Despite their important roles in cancer immunology, the subtypes of TAMs that influence TLS and their correlation with prognosis are not completely understood. Here, we provide novel insights into the role of TAMs in regulating TLS formation. Furthermore, we discuss the prognostic value of these TAM subtypes and TLS, as well as the current antitumour therapies for inducing TLS. This study highlights an entirely new field of TLS regulation that may lead to the development of an innovative perspective on immunotherapy for cancer treatment.

Applications of image-guided locoregional transarterial chemotherapy in patients with inoperable colorectal cancer: a review

With the development of comprehensive treatment, locoregional transarterial chemotherapy has become an alternative conversion therapy, palliative therapy, and neoadjuvant therapy for many solid malignant tumors. Locoregional transarterial chemotherapy, which is most frequently used for treating liver cancer, has the characteristics of high regional efficacy and few systemic adverse reactions. In recent years, the number of relevant reports of locoregional chemotherapy for treating initially inoperable colorectal cancer (CRC), including non-metastatic and metastatic CRC, has gradually increased. However, the specific treatment options for such locoregional therapy are not the same, and its indications, medication regimens and combined treatments have not reached any consensus. In this review, the application status of locoregional transarterial chemotherapy in primary and metastatic CRC patients has been reviewed and summarized to provide a reference for future clinical work and scientific research.

Genomic and immune microenvironment features influencing chemoimmunotherapy response in gastric cancer with peritoneal metastasis: a retrospective cohort study

BACKGROUND

Patients with peritoneal metastasis (PM) from gastric cancer (GC) exhibit poor prognosis. Chemoimmunotherapy offers promising clinical benefits; however, its efficacy and predictive biomarkers in a conversion therapy setting remain unclear. The authors aimed to retrospectively evaluate chemoimmunotherapy efficacy in a conversion therapy setting for GC patients with PM and establish a prediction model for assessing clinical benefits.

MATERIALS AND METHODS

A retrospective evaluation of clinical outcomes encompassed 55 GC patients with PM who underwent chemoimmunotherapy in a conversion therapy setting. Baseline PM specimens were collected for genomic and transcriptomic profiling. Clinicopathological factors, gene signatures, and tumor immune microenvironment were evaluated to identify predictive markers and develop a prediction model.

RESULTS

Chemoimmunotherapy achieved a 41.8% objective response rate and 72.4% R0 resection rate in GC patients with PM. Patients with conversion surgery showed better overall survival (OS) than those without the surgery (median OS: not reached vs 7.82 m, P <0.0001). Responders to chemoimmunotherapy showed higher ERBB2 and ERBB3 mutation frequencies, CTLA4 and HLA-DQB1 expression, and CD8+ T cell infiltration, but lower CDH1 mutation and naïve CD4+ T cell infiltration, compared to nonresponders. A prediction model was established integrating CDH1 and ERBB3 mutations, HLA-DQB1 expression, and naïve CD4+ T cell infiltration (AUC=0.918), which were further tested using an independent external cohort (AUC=0.785).

CONCLUSION

This exploratory study comprehensively evaluated clinicopathological, genomic, and immune features and developed a novel prediction model, providing a rational basis for the selection of GC patients with PM for chemoimmunotherapy-involved conversion therapy.

Single-cell RNA sequencing reveals the immune microenvironment landscape of osteosarcoma before and after chemotherapy

Chemotherapy, a primary treatment for osteosarcoma (OS), has limited knowledge regarding its impact on tumor immune microenvironment (TIME). Here, tissues from 6 chemotherapy-naive OS patients underwent single-cell RNA sequencing (scRNA-seq) and were analyzed alongside public dataset (GSE152048) containing 7 post-chemotherapy OS tissues. CD45+ (PTPRC+) cells were used for cell clustering and annotation. Changes in immune cell composition pre- and post-chemotherapy were characterized. Totally, 28,636 high-quality CD45+ (PTPRC+) cells were extracted. Following chemotherapy, the proportions of regulatory T cells (Tregs) and activated CD8 T cells decreased, while CD8 effector T cells increased. GO analysis indicated that differentially expressed genes (DEGs) in T cells were associated with cell activation, adaptive immune response, and immune response to tumor cells. Furthermore, the proportions of plasma cells increased, while naive B cells decreased. B cell surface receptors expression was upregulated, and GO analysis revealed DEGs of B cells were mainly enriched in B cell-mediated immunity and B cell activation. Moreover, M2 polarization of macrophages was suppressed post-chemotherapy. Overall, this study elucidates chemotherapy remodels the OS TIME landscape, triggering immune heterogeneity and enhancing anti-tumor properties.