Etiologies of delayed diagnosis and six-month outcome of patients with newly diagnosed advanced lung cancer with respiratory failure at initial presentation.

Background This study aimed to evaluate the characteristics of patients with newly diagnosed advanced lung cancer who initially presented with respiratory failure. Methods This was a retrospective study which analyzed patients in the intensive care unit (ICU) with newly diagnosed advanced lung cancer who were placed on mechanical ventilation (MV). We defined newly diagnosed lung cancer as pathological or molecular results for treatment decisions not yet determined when the patient was admitted to ICU. Results During the 14-year inclusion period, 845 lung cancer patients requiring MV were screened. A total of 56 newly diagnosed extensive lung cancer patients were analyzed. Cancer-related to central airway obstruction (n= 29, 51.8%) was the leading cause of respiratory failure. The significant etiologies of delay in the diagnosis of lung cancer were diagnostic error, mistaking cancer for tuberculosis, and missed hilar lesions. The six-month survival rate was only 7.1% (n= 4). The sequential organ failure assessment (SOFA) score was significantly associated with mortality (HR = 1.142, 95% CI = 1.012-1.288,P= 0.031). The six-month survival rate in patients receiving suitable targeted therapy and accepting chemotherapy and best supportive care was 40% (2/5), 0% (0/7), and 4.5% (2/44), respectively. Conclusions Patients with newly diagnosed advanced lung cancer with acute life-threatening respiratory failure have poor outcomes. Cancer-related to central airway obstruction is a leading cause of respiratory failure. Diagnostic errors such as tuberculosis and missed hilar lesions are the two main etiologies of a delay in diagnosis. The SOFA score is correlated with mortality. Targeted therapy can raise the six-month survival rates in patients with oncogenic mutation adenocarcinoma, who survive after presentation in a critical condition.