Treatment Timeliness in Extensive-Stage SCLC and Impact on Survival: A Registry-Based Observational Study

A key dogma in the management of extensive-stage SCLC (ES-SCLC) is rapid diagnosis and treatment. However, the impact of treatment timeliness in a real-world setting is incompletely understood.

Patients with ES-SCLC were identified from the Victorian Lung Cancer Registry (VLCR). Referral-to-diagnosis, referral-to-treatment, and diagnosis-to-treatment intervals were calculated and defined as timely if they were less than 28 days, 42 days, and 14 days, respectively. The impact of timeliness on overall survival was determined using univariable and multivariable Cox proportional hazards regression.

From January 2012 to April 2023, the VLCR enrolled 1195 patients with ES-SCLC, including 995 who were treated with chemotherapy. The median referral-to-diagnosis, referral-to-treatment, and diagnosis-to-treatment intervals were 8 days (interquartile range [IQR] 4-17 days), 18 days (IQR 10-31 days), and 7 days (IQR 4-13 days), respectively. Mortality risk was greater with a shorter diagnosis-to-treatment time (hazard ratio [HR], 1.31 for <14 days versus ≥14 days; 95% confidence interval [CI]: 1.12-1.54; p = 0.001), which was corroborated by multivariable regression (adjusted HR, 1.32; 95% CI: 1.13-1.56; p = 0.001). Poorer survival was also observed with a shorter referral-to-diagnosis interval (adjusted HR, 1.37 for <28 days versus ≥28 days; 95% CI: 1.10-1.71; p = 0.005) and shorter referral-to-treatment interval (adjusted HR, 1.58 for <42 days versus ≥42 days; 95% CI: 1.28-1.95; p <0.0001).

Most patients captured in the VLCR received timely care. Although earlier treatment predicted worse overall survival, the effects of timely care on symptom control and quality of life remain important considerations that require further characterization.