Abstract
RATIONALE: Immune checkpoint inhibitors have been rapidly developed for lung cancer therapy and major clinical guidelines have recommended them as the optimal first-line treatment for PD-L1-positive advanced lung cancer. Unfortunately, there is a lack of efficient prediction tools for the occurrence of immune-related adverse events (irAEs) caused by immunotherapy, and there is a lack of real-world data on the processing of irAEs, particularly those occurring in multiple systems simultaneously. PATIENT CONCERNS: We report a 62-year-old male with expectoration who was diagnosed with lung adenocarcinoma with brain and bone metastases. DIAGNOSES: The results of the lung cancer tissue biopsy showed lung adenocarcinoma. Gene detection results of lung cancer tissue biopsy showed that the KRAS gene G12D was mutated and PD-L1 was positive, with a tumor proportion score of 95% (Dako 22C3 IHC platform). INTERVENTIONS: The patient initially received 1 cycle of pemetrexed in combination with cisplatin-based chemotherapy. After the results of PD-L1 testing were reported, he received 1 cycle of camrelizumab immunotherapy in combination with pemetrexed plus cisplatin based chemotherapy. OUTCOMES: Seventeen days after treatment, the patient presented with symptoms such as yellow staining of the sclera and skin, itching throughout the body, dry mouth, and ecchymosis of the skin of the right lower extremity, which continued to worsen. Following treatment with 2 mg/kg methylprednisolone, the patient's condition continued to deteriorate. IrAEs were controlled after dose escalation to 8 mg/kg in combination with plasma exchange therapy and treatment with multiple doses of mycophenolate ester. The patient then received no treatment for almost 2 months, but examination revealed that the tumor still had a persistent shrinkage reaction. LESSONS: Camrelizumab has been well tolerated in several studies, but in patients with high PD-L1 expression and a G12D mutation in KRAS, one should be alert to the development of serious or even multisystem immune-related adverse effects. Timely and individualized selection of the hormone dosage is essential for the treatment of immunotherapy-induced multisystem irAEs.