Patterns of Infection and Their Impact on Survival in Lung Cancer Patients: A Retrospective Study From Saudi Arabia

Globally, Lung cancer remains one of the leading causes of cancer-related mortalities. Infection-related complications represent a relevant concern in lung cancer patients’, being substantial risk factors for morbidity and mortality. This study aims to a) determine the prevalence of infection among lung cancer patients’, b) identify the predominant pathogens and infection type, c) evaluate the impact of infection on the overall patients’ survival, and d) evaluate potential factors impact on patients’ overall survival. In this retrospective study, clinical and laboratory data from 394 lung cancer patients treated at King Faisal Specialist Hospital & Research Center in Riyadh, Saudi Arabia, between 2015 and 2019, were analyzed. Descriptive statistics summarized patients’ characteristics. Associations were assessed using a chi-square test, and survival differences were analyzed using Kaplan-Meier and univariate cox proportional hazard regression analysis. Multivariate Cox proportional hazards regression was conducted to assess the potential factors that affect patients’ survival. A p-value < 0.05 was considered statistically significant. Among 394 lung cancer patients 153 (38.8%) developed infections. Bacterial infection were most prevalent (54.25%), followed by polymicrobial infections (32.03%), viral (9.80%), fungal (3.27%), and parasitic infection (0.65%). Gram-negative bacteria were the most predominant pathogens (44.35%). Diabetes mellitus was significantly associated with infection (p = 0.004). Patients without infection had significantly higher survival rates (p = < 0.001). Multivariate Cox proportional hazards regression showed that tumor stage (stage IV), immunotherapy, targeted therapy, and surgical intervention have a significant effect on patient’s survival. Infections, particularly bacterial and gram negative, are common and negatively impact survival in lung cancer patients. Early identification and management of infections, especially among diabetic patients, may improve clinical outcomes. The crucial need to promptly identify the causative agents associated with lung cancer patients, as this can significantly enhance patients’ survival rates.