Durable Response After Combination Of Concurrent Chemoradiotherapy And Anti-PD-1 Therapy In HER2-Negative Advanced Gastric Adenocarcinoma: A Case Report

Long-term survival in a patient with multiple metastatic gastric cancer treated with PTX plus emvolimab and disitamab vedotin: case report and treatment experience: A case report

RATIONALE

Most Chinese patients with locally advanced gastric cancer at diagnosis have an overall 5-year survival rate of <50%. Surgical resection alone is not suitable for patients with locally advanced gastric cancer. Currently, comprehensive treatment is the focus of locally advanced gastric cancer.

PATIENTS CONCERNS

The patient, a 56-year-old female, was admitted to the hospital because of "4 + months of double hydronephrosis found during a physical examination." Who was admitted for computer tomography and gastroscopy examinations, and take pathological tissue specimens during endoscopic examination.

DIAGNOSES

Computed tomography assessment indicated ulcerative gastric cancer with an abdominal implant, bladder, and bone metastases. An endoscopic examination revealed that the ulcer of the gastric angle was huge, and through relevant auxiliary examinations, the diagnosis of this disease is gastric cancer complicated with multiple metastases to bladder, rectum, lumbar spine, and peritoneum. Clinically diagnosed as cT4bN3M1.

INTERVENTIONS

The patient is currently undergoing first, second, and third line neoadjuvant therapy, combined with immunotherapy, targeted therapy, neoadjuvant intraperitoneal systemic chemotherapy, nutritional support, and other treatment plans.

OUTCOMES

After 15 cycles of treatment, the progression-free survival had reached 15 months. The patient had an NRS2002 score of 1, an ECOG score of I, a quality of life score of 55, albumin of 35.27 g/L, and a decrease in abdominal and pelvic fluid accumulation and exudation compared to before.

LESSONS

We demonstrated high survival of almost 3 years in a patient with gastric cancer that was complicated by bone, peritoneal, rectal, and bladder metastases. The combination of immunotherapy, targeted therapy, and neoadjuvant intraperitoneal systemic chemotherapy, along with the maintenance of nutritional status and CTCs could be a valuable modality for the subsequent treatment and observation of similar patients.

An abscopal effect in a gastric cancer patient treated with combined chemoimmunotherapy and palliative radiotherapy

The prognosis of advanced gastric cancer remains poor. Palliative radiotherapy has been utilized to palliate bleeding in unresectable gastric cancer. Recent studies have described that a systemic immune response may be induced by local radiotherapy to the primary tumor lesion. Here we report a rare case of an abscopal effect in a patient with inoperable gastric cancer combined with tumor hemorrhage. A short course of radiotherapy was performed to palliate bleeding; additionally, the patient was treated with chemotherapy and immunotherapy. Complete response was achieved in the lung metastasis lesion. The observed abscopal effect suggests that there may be a synergistic effect between immunotherapy and radiotherapy. This case report supports the combination of immunotherapy and radiotherapy in patients with advanced gastric cancer.

Research status on immunotherapy trials of gastric cancer

The breakthrough of immune checkpoint inhibitor (ICI) therapy has created extensive opportunities for cancer immunotherapy. Especially, the block of programmed death-1/programmed death ligand 1 (PD-L1) axis using ICIs has become a new therapeutic strategy to treat advanced gastric cancer (GC). However, in the past decade, single-arm and randomized trials for single-drug ICI therapy showed that the therapeutic effect was not satisfactory, including clinical trials for advanced GC. However, after selecting suitable predictive biomarkers and developing a combination of anti-angiogenic targeted drugs and other chemotherapeutic drugs, the objective response rate and progression-free survival of patients with gastric cancer were improved significantly. The United States Food and Drug Administration has approved treatment with pembrolizumab for patients with advanced GC with PD-L1 expression or microsatellite instability-high/mismatch repair deficiency. In this review, the updated data from the latest trial results of combination immunotherapy for GC are presented. Based on the outcome of combination therapy, we discuss its possible molecular mechanism and summarize effective predictive biomarkers. We also discuss possible problems stemming from results of other clinical trials of ICI treatment and propose other directions for ICI therapy.

Downregulation of lncRNA HCP5 has inhibitory effects on gastric cancer cells by regulating DDX21 expression

LncRNA HCP5 has been confirmed to play crucial roles in many types of cancers. However, the role of lncRNA HCP5 in regulating the occurrence and development of gastric cancer (GC) remains unknown. In the current study, we aimed to investigate the precise effects of lncRNA HCP5 on cell proliferation, migration and invasion and molecular mechanisms in gastric cancer. Using RT-qPCR analysis, we found that lncRNA HCP5 was differentially expressed in GC cell lines. CCK-8, wound healing and transwell assay indicated that the proliferation, migration and invasion of gastric cancer cells were inhibited by downregulation of lncRNA HCP5 and lncRNA HCP5 overexpression exhibited the opposite effects in gastric cancer cells. Mechanistically, RNA binding protein immunoprecipitation and dual luciferase reporter assay confirmed the interaction between lncRNA HCP5 and DDX21. The effects of lncRNA HCP5 overexpression the proliferation, migration and invasion of GC cells were partly rescued by DDX21 silencing. Taken together, downregulation of lncRNA HCP5 exerted inhibitory effects on GC cell proliferation, migration and invasion through modulation of DDX21 expression, demonstrating the function of lncRNA HCP5 and DDX21 in GC progression.

Predictive biomarkers and mechanisms underlying resistance to PD1/PD-L1 blockade cancer immunotherapy

Immune checkpoint blockade targeting PD-1/PD-L1 has promising therapeutic efficacy in a variety of tumors, but resistance during treatment is a major issue. In this review, we describe the utility of PD-L1 expression levels, mutation burden, immune cell infiltration, and immune cell function for predicting the efficacy of PD-1/PD-L1 blockade therapy. Furthermore, we explore the mechanisms underlying immunotherapy resistance caused by PD-L1 expression on tumor cells, T cell dysfunction, and T cell exhaustion. Based on these mechanisms, we propose combination therapeutic strategies. We emphasize the importance of patient-specific treatment plans to reduce the economic burden and prolong the life of patients. The predictive indicators, resistance mechanisms, and combination therapies described in this review provide a basis for improved precision medicine.