Penpulimab in an adolescent patient with pancreatic neuroendocrine carcinoma with liver metastasis: A case report and literature review.

RATIONALE: Pancreatic neuroendocrine carcinoma (PNEC) is a rare, aggressive malignancy with limited therapeutic options and a dismal prognosis, particularly in young patients. Approximately 85% of PNEC cases eventually progress to metastatic cancer. Despite advances in oncology, optimal management strategies for metastatic PNEC remain undefined, especially in chemotherapy-ineligible cases.

PATIENT CONCERNS: An 18-year-old male patient, reporting anorexia with associated weight loss (15 kg weight loss over 3 months) and significant abdominal distension.

DIAGNOSES: The results of whole abdominal computed tomography, histopathology, immunohistochemistry, and laboratory examination were consistent with pancreatic neuroendocrine carcinoma with liver metastasis.

INTERVENTIONS: Due to the family refusal of chemotherapy, and immunohistochemistry revealed programmed death-1 ligand positivity. The patient received penpulimab (anti-programmed death-1) combined with anlotinib capsules and then changed to penpulimab combined with sorafenib capsules after progression.

OUTCOMES: Initial therapy achieved 13 months of progression-free survival, demonstrating durable disease control. Subsequent progression highlighted challenges of acquired resistance, with no severe treatment-related toxicity. The patient was still alive at the time of follow-up in July 2024.

LESSONS: Pancreatic neuroendocrine cancer is rare. There are various treatment options available. However, the best treatment plan still needs further exploration. This case underscores that programmed death-1 ligand + PNEC may respond to immunotherapy/antiangiogenic combinations, offering alternatives for chemotherapy-ineligible patients. In addition, young patients with aggressive PNEC represent an understudied population, necessitating tailored strategies.