Routes to Diagnosis in Danish Lung Cancer Patients: Emergency Presentation, Age and Smoking History-A Population-Based Cohort Study.

Background: The fast-track cancer pathway aims to expedite diagnosis of lung cancer and treatment and is the preferred route to diagnosis. Diagnosis following an unplanned admission (unplanned route) has been associated with poor outcomes.

Objective: This study explores factors associated with lung cancer diagnosis following unplanned admissions, focusing on the elderly population.

Methods: A retrospective cohort study using population-based data from Danish registries. Factors such as age, comorbidity, performance status, smoking history, socioeconomic parameters and treatment modality were analyzed in relation to route to diagnosis and prognosis.

Results: Among 17,835 patients, 16% were elderly (≥ 80 years). The unplanned route constituted 28% of diagnostic routes, with higher proportion among the elderly (33%). Poor performance status and advanced disease stage were associated with the unplanned route. Married patients were less likely to undergo an unplanned route to diagnosis. Smoking did not significantly influence diagnostic route. The adjusted odds ratio for curative treatment and dying 12 months after diagnosis, following unplanned route to diagnosis were 0.68 (95% CI, 0.61-0.76) and 1.48 (95% CI, 1.36-1.61), respectively.

Conclusion: Frailty (poor performance status and high burden of comorbidity) in addition to unfavorable socioeconomic factors, which all were more prevalent among elderly patients, were associated with undergoing an unplanned route to diagnosis. However, age itself was not. Diagnosis following unplanned admission correlated with reduced likelihood of curative treatment and poorer prognosis. Expanding screening initiatives to include frail elderly individuals living alone, along with alertness by primary care clinicians, is warranted to improve outcomes for these patients.