Case report describes sintilimab-associated toxic epidermal necrolysis in gastric carcinoma patient

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Frontiers in Medicine Published April 22, 2026 Medically reviewed April 25, 2026 DOI ↗ By Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development

Key Takeaway

Recognize delayed toxic epidermal necrolysis risk with sintilimab in gastric cancer patients.

This publication is a case report focusing on a patient with gastric carcinoma treated with neoadjuvant sintilimab combined with the SOX regimen. The authors describe the occurrence of delayed-onset toxic epidermal necrolysis as a serious adverse event requiring discontinuation of immunotherapy. The report highlights the management of this immune-related cutaneous adverse event alongside oncologic outcomes in a single individual.

Key findings indicate the patient achieved a complete pathological response confirmed by postoperative pathology. Regarding safety, the patient experienced gradual recovery of skin lesions with no recurrence of toxic epidermal necrolysis during follow-up after receiving methylprednisolone. The authors note that sintilimab-induced toxic epidermal necrolysis can occur as a delayed immune-mediated reaction, even after drug discontinuation. This temporal relationship suggests a potential immune-mediated mechanism despite the delayed presentation.

The authors acknowledge significant limitations, specifically that this evidence stems from a single case report. Consequently, generalizability is restricted, and causal relationships cannot be definitively established from this isolated observation alone. The certainty of the evidence remains low due to the absence of comparative data or larger cohorts to validate the incidence rate.

Practice relevance emphasizes that early recognition and timely immunosuppressive treatment are essential for favorable outcomes in similar clinical scenarios. Clinicians should monitor patients closely for cutaneous toxicity when using sintilimab, though broader recommendations await higher-quality evidence. Awareness of this rare complication is necessary for managing patients on immune checkpoint inhibitors in gastric cancer settings. The authors highlight the need for vigilance regarding delayed immune-mediated reactions that may persist after drug discontinuation.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedApr 2026

View Original Abstract ↓

BackgroundSintilimab, a programmed death-1 (PD-1) inhibitor widely used in various malignancies, has demonstrated favorable antitumor efficacy and safety. However, severe immune-related cutaneous adverse events (irCAEs) such as toxic epidermal necrolysis (TEN) are rare but potentially fatal. Understanding their clinical characteristics, treatment strategies, and pathophysiological mechanisms is crucial for optimal management.Case presentationWe report a case of a patient with gastric carcinoma who developed delayed-onset TEN after receiving four cycles of neoadjuvant sintilimab combined with the SOX regimen (S-1 and oxaliplatin). The patient subsequently underwent radical gastrectomy, and postoperative pathology confirmed a complete pathological response. On the third postoperative day, the patient developed a scattered erythematous rash that began on the back and spread to the upper abdomen and upper and lower limbs, forming plaques. A dermatology consultation and clinical evaluation led to a diagnosis of immune-related TEN. The patient received systemic methylprednisolone and comprehensive supportive care, resulting in a gradual recovery of skin lesions, with no recurrence of TEN during follow-up.DiscussionThis case suggests that sintilimab-induced TEN can occur as a delayed immune-mediated reaction, even after drug discontinuation. The potential mechanism of sintilimab-induced TEN may involve the excessive activation of cytotoxic T lymphocytes and dysregulated immune responses leading to keratinocyte apoptosis through Fas/FasL and perforin–granzyme pathways. Notably, the occurrence of irCAEs has been associated with favorable antitumor responses in some patients, reflecting strong immune activation. Prompt discontinuation of immunotherapy, early initiation of high-dose corticosteroids, and supportive measures remain the cornerstone of management. TNF-α or JAK inhibitors may provide therapeutic benefit in refractory cases.ConclusionThis case highlights a rare instance of delayed-onset TEN following sintilimab-based neoadjuvant therapy in gastric cancer, occurring shortly after surgical resection despite a complete pathological response. Early recognition and timely immunosuppressive treatment are essential for favorable outcomes. Further investigation into the mechanisms and predictive factors of PD-1 inhibitor–induced TEN is warranted.