Burden of chemotherapy-induced myelosuppression (CIM) in Chinese patients with extensive-stage small cell lung cancer (ES-SCLC): A retrospective real-world study

Abstract

Background

The disease burden, treatment patterns, and financial costs associated with chemotherapy-induced myelosuppression (CIM) in Chinese patients with extensive-stage small cell lung cancer (ES-SCLC) remain poorly characterized, particularly in terms of real-world evidence derived from large populations. This study aimed to describe the incidence, treatment patterns, costs, and healthcare resource utilization (HCRU) in Chinese patients with ES-SCLC who develop CIM.

Methods

Adults diagnosed with ES-SCLC who started etoposide–platinum (EP) chemotherapy for the first time between January 1, 2018 and December 31, 2022 were retrospectively identified in the Chinese National Cancer Information Database. Baseline demographic and clinical data were collected. Information on CIM-related events, treatment, costs, and HCRU during EP chemotherapy and during follow-up was assessed. Costs and HCRU were compared among patients with grade 3–4 CIM, grade 1–2 CIM, and no CIM using the Kruskal–Wallis test.

Results

In total, 7505 patients with ES-SCLC (mean age 61.2 years; 17.7 % [1332/7505] female; body mass index 23.2±3.3 kg/m²) were enrolled. After initiation of EP-based chemotherapy, 6901 patients (92.0 %) experienced at least one CIM-related event. At least one grade 3–4 CIM event occurred in 1883 patients (25.1 %) and consisted of single-lineage (neutropenia [n=609, 8.1 %], thrombocytopenia [n=85, 1.1 %], anemia [n=797, 10.6 %]), two-lineage (n=318, 4.2 %), and three-lineage (n=74, 1.0 %) events. Patients receiving immune checkpoint inhibitors (ICIs) plus EP (n=1674) had a significantly higher incidence of at least one CIM during the ICI combination therapy (87.8 % [1469/1674] vs. 82.8 % [4827/5831]; χ²=23.43, P<0.0001) and grade 3–4 CIM (25.7 % [430/1674] vs. 20.6 % [1201/5831]; χ²=19.51, P<0.0001) compared to those receiving other EP-based therapies during EP chemotherapy (n=5831). Rates of use of granulocyte colony-stimulating factor, thrombopoietin, interleukin-11, erythropoiesis-stimulating agents, and blood transfusion were 81.1 % (n=6087), 9.2 % (n=691), 12.4 % (n=927), 9.0 % (n=678), and 12.1 % (n=907), respectively. HCRU and total costs per patient were higher for those with grade 3–4 CIM than for those without CIM or grade 1–2 CIM, and significant differences in the total cost were observed across groups (H=195.54, P <0.0001).

Conclusion

Despite the availability of supportive care for CIM in patients with ES-SCLC in China, a considerable clinical and financial burden persists. Strategies that protect bone marrow from progressing to high-grade myelosuppression could reduce the burden on patients and healthcare organizations.