Comparison of 6 cycles with 4 cycles of chemotherapy and atezolizumab in the first-line treatment of ES-SCLC: a retrospective multicenter analysis
Year: 2026
Type: article
Study design: Observational Study
Abstract: AIM: IMpower133 was designed with 4 cycles of chemoimmunotherapy with atezolizumab, unlike many other studies permitted 6-cycle induction. This study aimed to compare the efficacy and safety of a 4-cycle regimen with an extended 6-cycle regimen of carboplatin, etoposide, and atezolizumab in the first-line treatment of extensive-stage small-cell lung cancer (ES-SCLC). METHODS: This retrospective multicenter study was conducted across 13 oncology centers in Turkey. A total of 181 patients with ES-SCLC who received first-line treatment with chemotherapy plus atezolizumab were analyzed and grouped into those receiving 4 cycles (n = 101) and 6 cycles (n = 80) of treatment. RESULTS: The median follow-up time was 20.9 months. The objective response rates were similar between the 4- and 6-cycle groups (79.2% vs 78.8%, P = .940). The disease control rates were also comparable (84.2% vs 86.3%, P = .940). The median progression-free survival (PFS) was 6.3 months in the 4-cycle and 8.1 months in the 6-cycle group (P = .357). The median overall survival (OS) was 16.6 months for the 4-cycle and 13.6 months for the 6-cycle group (P = .583). Intracranial progression was higher in the 4-cycle group (50.0% vs 25.5%, P = .007). Immune-related adverse events were similar between the groups. CONCLUSION: This is one of the largest real-world datasets comparing the efficacy and safety of 4 versus 6 cycles of induction chemoimmunotherapy. Although there were no significant improvements in PFS or OS, the 6-cycle regimen was associated with a lower observed rate of intracranial progression, predominantly among patients without baseline brain metastases. Further studies are needed to identify this subject in future.
Source: The Oncologist
Authors: Halil Göksel Güzel, Derya Kıvrak Salim, Saadettin Kılıçkap, Yasemin Kemal, Cengiz Akosman, Çağlar Köseoğlu, Alper Coşkun, Seval Orman, Safa Can Efil, Onur Baş, Esra Zeynelgil, Halil Çelik, Aytaç Terzi, Tuba Karaçelik, Nuri Karadurmuş, Erdem Çubukçu, Tuğba Başoğlu Tüylü, Burak Bilgin, Mustafa Erman, Serdar Karakaya, Kadir Eser, Elif Atağ, Melek Karakurt Eryılmaz, Banu Öztürk
Institutions: Antalya Eğitim ve Araştırma Hastanesi, Gülhane Eğitim ve Araştırma Hastanesi, Bursa Uludağ Üni̇versi̇tesi̇, Dr Lütfi Kırdar Kartal Eğitim ve Araştırma Hastanesi, Ankara Bilkent City Hospital, Hacettepe University Hospital, Ankara Atatürk Eğitim ve Araştırma Hastanesi, Mersin Üniversitesi, Dokuz Eylül University, Dokuz Eylül Üniversitesi Hastanesi, Necmettin Erbakan University
Language: English
Topic: Lung Cancer Research Studies
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,852
OpenAlex ID: W7136406952