Atezolizumab Lung Toxicity: Importance of Combination Treatment on the Edge of Life, A Case Report

Background: Lung cancer is one of the most common and mortal cancers worldwide. According to pathological and clinical groups, treatments vary, and a tailored approach is considered. Adjuvant therapies, such as chemotherapy, radiation, and immune checkpoint inhibitors (ICI), are recommended by recent guidelines for patients with locally advanced cancer. Objective: This study aimed to report the case of a patient with stage 2B squamous cell lung carcinoma who was managed for pulmonary toxicity after receiving adjuvant chemotherapy and atezolizumab treatment. Case Report: A 66-year-old male patient received chemotherapy and immunotherapy after surgery for squamous cell lung cancer. A diagnosis of atezolizumab-associated pneumonitis was made using laboratory tests and imaging due to the patient's worsening dyspnea after treatment. Due to the patient's rapid progression, pulse steroid and MMF therapy were administered concurrently. When Klebsiella pneumoniae growth was detected in the sputum culture during the follow-up, IVIg was used to supplement the medication. The patient showed significant clinical and radiological improvement. Conclusion: In this study, we present an atezolizumab-induced pneumonitis case of a squamous cell lung cancer patient. It may be life-saving not to avoid aggressive treatment approaches by combining the steps of guideline recommendations in patients with rapidly progressive pneumonitis.