A systematic review of survival following anti-cancer treatment for small cell lung cancer

Objectives: We conducted a systematic review and meta-analysis of survival following treatment recommended by the European Society of Medical Oncology for SCLC in order to determine a benchmark for novel therapies to be compared with. Materials and methods: Randomized controlled trials and observational studies reporting overall survival following chemotherapy for SCLC were included. We calculated survival at 30 and 90-days along with 1-year, 2-year and median. Results: We identified 160 for inclusion. There were minimal 30-day deaths. Survival was 99 % (95 %CI 98.0–99.0 %, I²33.9 %, n = 77) and 90 % (95 %CI 89.0–92.0 %, I²79.5 %, n = 73) at 90 days for limited (LD-SCLC) and extensive stage (ED-SCLC) respectively. The median survival for LD-SCLC was 18.1 months (95 %CI 17.0–19.1 %, I²77.3 %, n = 110) and early thoracic radiotherapy (thoracic radiotherapy 18.4 months (95 %CI 17.3–19.5, I²78.4 %, n = 100)) vs no radiotherapy 11.7 months (95 %CI 9.1–14.3, n = 10), prophylactic cranial irradiation (PCI 19.7 months vs No PCI 13.0 months (95 %CI 18.5–21.0, I²75.7 %, n = 78 and 95 %CI 10.5–16.6, I²81.1 %, n = 15 respectively)) and better performance status (PS0–1 22.5 months vs PS0–4 15.3 months (95 %CI 18.7–26.1, I²72.4 %, n = 11 and 95 %CI 11.5–19.1 I²77.9 %, n = 13)) augmented this. For ED-SCLC the median survival was 9.6 months (95 %CI 8.9–10.3 %, I²95.2 %, n = 103) and this improved when irinotecan + cisplatin was used, however studies that used this combination were mostly conducted in Asian populations where survival was better. Survival was not improved with the addition of thoracic radiotherapy or PCI. Survival for both stages of cancer was better in modern studies and Asian cohorts. It was poorer for studies administering carboplatin + etoposide but this regimen was used in studies that had fewer patient selection criteria. Conclusion: Early thoracic radiotherapy and PCI should be offered to people with LD-SCLC in accordance with guideline recommendations. The benefit of the aforementioned therapies to treat ED-SCLC and the use of chemotherapy in people with poor PS is less clear.