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Updated: Aug 4, 2025
Genome-Wide Analysis of DNA Methylation in Gastrointestinal Cancer
Published on: September 18, 2020
Pathologic complete response to chemoimmunotherapy of an advanced gastric cancer patient with high PD-L1 expression,
Hongpeng Jiang1, Junyun Wang2, Wei Deng1
1Department of General Surgery, Beijing Friendship Hospital, Capital Medical University & National Clinical Research Center for Digestive Diseases, Beijing, China.
Background:
Advanced gastric cancer (AGC) is a malignant disease with limited therapeutic options and a poor prognosis. Recently, immune checkpoint inhibitors (ICIs), represented by inhibitors of programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1), have emerged as a potential gastric cancer (GC) therapy.
Case Presentation:
This case study aimed to reveal the tumor response to neoadjuvant chemotherapy combined with camrelizumab in a patient with AGC based on the characteristics of the clinical pathology, genomics variation, and gut microbiome. Samples from a 59-year-old male patient diagnosed with locally advanced unresectable GC (cT4bN2M0, high grade) presenting PD-L1-positive, deficient mismatch repair (dMMR), and highly specific gut microbiota enrichment were subjected to target region sequencing, metagenomic sequencing, and immunohistochemistry staining. The patient received neoadjuvant therapy, including camrelizumab, apatinib, S-1, and abraxane, which eventually promoted dramatic tumor shrinkage without serious adverse effects and allowed subsequent radical gastrectomy and lymphadenectomy. Finally, the patient achieved pathologic complete response (pCR), and the recurrence-free survival time was 19 months at the last follow-up in April 2021.
Conclusions:
The patient with PD-L1-positive, dMMR, and a highly specific gut microbiota enrichment exhibited a pCR to neoadjuvant chemoimmunotherapy.
Insights
A patient with advanced gastric cancer (AGC) achieved a pathologic complete response (pCR) after neoadjuvant chemoimmunotherapy. This treatment combined immune checkpoint inhibitors (ICIs) with chemotherapy, showing promising results for PD-L1-positive, dMMR tumors.
Area of Science:
- Oncology
- Immunotherapy
- Gastrointestinal Cancer Research
Background:
- Advanced gastric cancer (AGC) presents limited treatment options and a poor prognosis.
- Immune checkpoint inhibitors (ICIs), targeting programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1), are emerging as a potential therapy for gastric cancer (GC).
Observation:
- A case study focused on a 59-year-old male patient with locally advanced unresectable GC (cT4bN2M0, high grade).
- The patient's tumor was characterized as PD-L1-positive, deficient mismatch repair (dMMR), with highly specific gut microbiota enrichment.
- Diagnostic methods included target region sequencing, metagenomic sequencing, and immunohistochemistry staining.
Findings:
- The patient received neoadjuvant therapy comprising camrelizumab, apatinib, S-1, and abraxane.
- This regimen resulted in dramatic tumor shrinkage with no serious adverse effects, enabling radical gastrectomy and lymphadenectomy.
- The patient achieved a pathologic complete response (pCR), with 19 months of recurrence-free survival as of April 2021.
Implications:
- PD-L1-positive, dMMR status, coupled with specific gut microbiota, may predict response to neoadjuvant chemoimmunotherapy in AGC.
- This case highlights the potential of combining ICIs with chemotherapy for achieving pCR in advanced gastric cancer.
- Further research into gut microbiome's role in chemoimmunotherapy response is warranted for personalized GC treatment strategies.
