Tumor lysis syndrome in a patient with advanced lung squamous cell carcinoma undergoing combined therapy with a programmed cell death protein 1 inhibitor and first‑line chemotherapy: A case report

Tumor lysis syndrome (TLS) is a rare but serious complication in patients with solid tumors. It is characterized by a complex array of metabolic disturbances and clinical symptoms, resulting from the release of cellular contents into the bloodstream after tumor cell lysis. The present study reports the case of a patient with advanced lung squamous cell carcinoma (SCC) who developed TLS following combined treatment with PD‑1 inhibitors and first‑line chemotherapy. The treatment strategy included intravenous fluid replacement, urine alkalinization, uric acid reduction, renal protection and electrolyte stabilization, leading to the normalization of laboratory values. After one cycle of the combined therapy, the patient achieved a partial response, classified using the Response Evaluation Criteria in Solid Tumours 1.1 criteria. To the best of our knowledge, this is the first reported case of TLS in a patient with advanced lung SCC receiving concurrent PD‑1 inhibitor and chemotherapy treatment. Given the increasing use of PD‑1 inhibitors, it is essential to remain vigilant about the potential for TLS in solid tumors. Prompt intervention in high‑risk patients, ongoing monitoring after treatment, and early detection of TLS are vital to improve patient adherence, ensure continuity of care and enhance outcomes.