The Role of Adjuvant Therapy Following Surgical Resection of Small Cell Lung Cancer: A Multi-Center Study

Application of postoperative adjuvant radiotherapy in limited-stage small cell lung cancer: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

One of the most important treatments for small cell lung cancer (SCLC) is radiation therapy. Currently, the criteria for administering postoperative adjuvant radiotherapy (PORT) in SCLC remain uncertain. Therefore, we conducted a meta-analysis to investigate the influence of PORT on the prognosis of limited-stage SCLC (LS-SCLC).

METHODS

We conducted a comprehensive search across three databases, PubMed, Embase, and the Cochrane Library. Data analysis involved utilizing both random-effects and fixed-effects models for pooling the results. A comparative analysis was performed to assess the prognostic outcomes of patients with LS-SCLC who did and did not undergo PORT. The primary outcome assessed was overall survival (OS), while the secondary outcome was disease-free survival (DFS).

RESULTS

This analysis included 11 retrospective studies comprising 7694 eligible participants. Among the entire population of LS-SCLC patients, the OS was superior in those receiving PORT than in those not receiving it (hazard ratio [HR]: 0.79, 95 % confidence interval [CI]: 0.71-0.87; P < 0.0001). In pN0 stage LS-SCLC patients, PORT was associated with a detrimental effect on OS (HR: 1.22, 95 % CI: 1.04-1.43; P = 0.01). In pN1 stage LS-SCLC patients, additionally administering PORT did not provide a significant OS advantage as compared to not administering it (HR: 0.82, 95 % CI: 0.60-1.12; P = 0.21). In pN2 stage LS-SCLC patients, those receiving PORT demonstrated a significant improvement in OS (HR: 0.59; 95 % CI: 0.50-0.70; P < 0.0001) as compared to those not receiving it. Regarding DFS in LS-SCLC patients, the difference in the protective effect with and without the administration of PORT was less pronounced (HR: 0.76, 95 % CI: 0.58-1.00; P = 0.053).

CONCLUSIONS

With respect to OS, PORT is not advisable in patients with pN0 or pN1 stage LS-SCLC but is highly recommended in pN2 stage LS-SCLC. Further research is warranted to confirm these findings.

A 15-Gene-Based Risk Signature for Predicting Overall Survival in SCLC Patients Who Have Undergone Surgical Resection

Small cell lung cancer (SCLC) is a malignancy with a poor prognosis whose treatment has not progressed for decades. The survival benefit of surgery and the selection of surgical candidates are still controversial in SCLC. This study is the first report to identify transcriptomic alterations associated with prognosis and propose a gene expression-based risk signature that can be used to predict overall survival (OS) in SCLC patients who have undergone potentially curative surgery. An integrative transcriptome analysis of three gene expression datasets (GSE30219, GSE43346, and GSE149507) revealed 1734 up-regulated and 2907 down-regulated genes. Cox-Mantel test, Cox regression, and Lasso regression analyses were used to identify genes to be included in the risk signature. EGAD00001001244 and GSE60052-cohorts were used for internal and external validation, respectively. Overall survival was significantly poorer in patients with high-risk scores compared to the low-risk group. The discriminatory performance of the risk signature was superior to other parameters. Multivariate analysis showed that the risk signature has the potential to be an independent predictor of prognosis. The prognostic genes were enriched in pathways including regulation of transcription, cell cycle, cell metabolism, and angiogenesis. Determining the roles of the identified prognostic genes in the pathogenesis of SCLC may contribute to the development of new treatment strategies. The risk signature needs to be validated in a larger cohort of patients to test its usefulness in clinical decision-making.