The study included 186 patients who had recently been diagnosed with advanced lung cancer (Stage IV). Investigators were curious about the relationship between depression levels and systemic inflammation ratio (SIR) biomarker levels at diagnosis. SIRs are made up of three biomarkers that are linked to inflammation in the body, which has been linked to lower survival rates. All participants also filled out a depression questionnaire. According to the findings, 35% of patients had moderate to severe depressive symptoms.