Impact of patient and tumor characteristics on various aspects of the non-small cell lung cancer patient journey in Romania, Bulgaria, Serbia: A multicenter, non-interventional, retrospective cohort study.

[BACKGROUND] Lung cancer is the leading cause of cancer deaths worldwide, with non-small cell lung cancer (NSCLC) being most common. This study examines how patient and tumor characteristics influences NSCLC treatment in Romania, Bulgaria, and Serbia, highlighting regional disparities and aiming to improve outcomes.

[METHODS] This retrospective cohort study of stage IV NSCLC patients in Romania, Bulgaria, and Serbia analyzed the impact of patient and tumor characteristics on treatment choices, timelines for diagnosis, biomarker testing, and imaging, using regression analyses.

[RESULTS] The study included 840 stage IV NSCLC patients (mean age 64.2 years) across Romania, Bulgaria, and Serbia, with 280 patients per country. Overall, chemo-immunotherapy (CIT) was most common (38.1 %), followed by immunotherapy (31.2 %). Bulgaria and Romania favored CIT, while Serbia's options were limited by reimbursement. Factors influencing treatment included programmed death-ligand 1 (PD-L1) status and gene mutation profile in Bulgaria, weight loss and appetite in Romania, and smoking status and symptoms in Serbia. Testing and treatment initiation times varied, with Serbia showing the shortest times. PD-L1 status and Eastern Cooperative Oncology Group performance were crucial across all countries. Common symptoms included chest pain, cough, shortness of breath, and general pain, with varying frequencies across countries.

[CONCLUSION] This retrospective three-country real-world cohort shows marked regional differences in first-line treatment and timing for stage IV NSCLC. Beyond clinical factors, health-system elements, reimbursement, biomarker-testing availability/turnaround, and access to chemo-immunotherapy, shape care. Addressing these offers policy-level opportunities to improve equitable, guideline-concordant treatment. Initiated after the most heated phase of the COVID-19 pandemic and conducted without contingency measures, thus study highlights the need for personalized medicine and improved healthcare infrastructure to address disparities in treatment and testing times.

[MICROABSTRACT] Non-small cell lung cancer (NSCLC) is the most common type of lung cancer worldwide. In this retrospective cohort study we examined how patient and tumor characteristics influences NSCLC treatment in Romania, Bulgaria, and Serbia, and revealed significant regional differences in baseline characteristics, treatment preferences, and influencing factors for stage IV NSCLC in these countries.