Factors associated with delayed treatment initiation in an unselected cohort of patients with small-cell lung cancer

Background: Small-cell lung cancer (SCLC) is an aggressive, rapidly progressive malignancy. Thus, expedient diagnosis and treatment initiation is important. This study identifies and quantifies factors associated with delayed diagnosis and treatment initiation in patients with SCLC and compares time to treatment in SCLC with a cohort of patients with non-small cell lung cancer (NSCLC).

Materials and methods: The study included all patients diagnosed with SCLC at a hospital in southern Norway in a ten-year period (2007-2016), and all NSCLC patients during the period 2013-2016. Total time to treatment (TTT), was defined as the number of days from date of referral due to suspicion of lung cancer to first day of treatment. Factors associated with prolonged TTT were estimated using multivariate median regression analysis.

Results: The median TTT and interquartile range (IQR) for the 183 patients with SCLC was 16 (10-23) days. Factors associated with delayed TTT included outpatient versus inpatient evaluation (+8.4 days), number of diagnostic procedures (+4.3 days per procedure), stage I-III versus stage IV (+3.6 days) and age (+2.1 days per 10 years). In 2013-16, TTT in SCLC was 3.5 days shorter than in the period before and less than half that of NSCLC in the same period, 15 (9-22) versus 33 (22-50) days (p = 0.001).

Conclusion: Shorter TTT is seen in higher stage, while longer TTT is a result of increasing complexity of the diagnostic process and treatment decisions of patients with curative intent treatment. Knowledge on delaying factors can shorten TTT and improve clinical practice.