e21096 Background: Small cell lung cancer (SCLC) is a highly proliferative and rapidly growing tumor with poor prognosis, even in limited disease (LD), and a timely and accurately high intensity therapy is necessary. During the concurrent chemoradiotherapy (CCRT), etoposide with platinum (EP) regimen is recommended, however, irinotecan with cisplatin (IP) regimen is also effective. Therefore, we performed a large-scale, retrospective and nationwide cohort study to analyze the efficacy of CCRT in patients with LD-SCLC Methods: The population data were extracted from the Health Insurance Review and Assessment Service of Korea database from January 1, 2008, to November 30, 2016. Among 14,490 patients with SCLC patients who received chemotherapy, a total of 4,496 patients with LD-SCLC were analyzed. The primary objectives were to evaluate the survival outcomes of CCRT for LD-SCLC. Results: Patients who received EP-CCRT (n = 4,187) had better PFS of 11.233 months (95% confidence interval (CI) 10.900 – 11.667, P = 0.0477) and prolonged OS of 22.233 months (95% CI 21.233 – 23.333, P < 0.0001) than those who received IP-CCRT (n = 259; PFS = 9.567 months, 95% CI = 8.500 – 10.667; OS = 16.433 months, 95% CI = 14.467 – 18.333; P = 0.0477). After the failure of CCRT, we observed that dual chemotherapy (n = 925; OS = 9.133 months, 95% CI = 8.400 - 10.100) has better survival benefit (P < 0.0001) than single agent chemotherapy (n = 815; OS = 7.500 months, 95% CI, 6.933 – 8.133). IP chemotherapy demonstrated a better OS (9.567 months, 95% CI, 8.667 – 10.333 vs. 7.100 months, 95% CI, 5.100 – 10.400, P = 0.0170, respectively) than EP regimen in the platinum-resistant group; patients with PFS within 6 months after CCRT. However, in platinum sensitive group; patients who recurred after 6 months, the clinical benefit of EP regimen was superior to IP regimen (OS = 17.183 months, 95% CI, 13.033 – 25.633 vs. 6.617 months, 95% CI, 5.433 – 7.767; P < 0.0001). Cox proportional hazards regression analysis demonstrated that age, EP-CCRT, and dyslipidemia retained significant associations with OS after adjusting for all variables. Conclusions: In Korean population, concurrent thoracic radiotherapy with EP regimen had significantly favorable effects on OS and PFS. In addition, after the failure of CCRT, combination chemotherapy had clinical benefits over single agents. Among combination chemotherapy, IP combination regimen showed significantly favorable effects on OS and PFS, especially in the platinum-resistant group.
Duration of Twice-Daily Thoracic Radiotherapy and Time From the Start of Any Treatment to the End of Chest Irradiation as Significant Predictors of Outcomes in Limited-Disease Small-Cell Lung Cancer
