Tocilizumab rapidly controlled refractory tumor fever in lung adenocarcinoma patient for 45 days

Fever is a frequent symptom in patients with lung cancer, often signaling infection. However, a subset of patients experiences tumor fever, a non-infectious, inflammatory response driven by the malignancy itself. This condition can be debilitating and refractory to conventional antipyretics like Ibuprofen, posing a significant diagnostic and therapeutic challenge. The cytokine Interleukin-6 (IL-6) is a known mediator of inflammation and fever, often elevated in cancer patients, suggesting its potential role in tumor fever pathogenesis and as a therapeutic target.

This case report details a patient with lung adenocarcinoma who developed a refractory fever of unknown origin for over 1 month following progression of first-line treatment. Extensive diagnostic workup, including comprehensive blood tests, pathogen screening, and imaging studies, ruled out infectious, autoimmune, and drug-induced etiologies, leading to a diagnosis of tumor fever. The fever remained unresponsive to Ibuprofen. Subsequently, the patient received a single intravenous administration of Tocilizumab, an IL-6 receptor antibody, as an intervention.

Following a single intravenous administration of Tocilizumab, the patient's refractory tumor fever was successfully controlled. The fever resolved within 12 hours of the dose. This rapid response was sustained, with the patient maintaining a normal body temperature for an extended period.

The patient remained afebrile for 45 days, from August 21 to October 4, 2025, demonstrating a durable antipyretic effect from the single dose of Tocilizumab.