Surgical treatment of small-cell lung cancer: long-term prognosis and patterns of adjuvant therapy

Abstract

Background: Small-cell lung cancer (SCLC) is a highly aggressive malignancy predominantly treated with chemotherapy or chemoradiotherapy. The role of surgical intervention in SCLC, however, remains inadequately defined. This study aimed to retrospectively analyze the clinical data of patients with SCLC who underwent surgical treatment to assess the impact of surgery combined with perioperative adjuvant therapy on long-term prognosis, with the goal of informing future treatment strategies.

Methods: This study included patients with SCLC who underwent surgical treatment at West China Hospital, Sichuan University, between 2005 and 2021. Prognostic factors influencing overall survival (OS) and disease-free survival (DFS) were analyzed using univariate and multivariate Cox regression models, in conjunction with the Kaplan-Meier method.

Results: A cohort of 121 patients with SCLC who underwent surgical treatment was included. Multivariate Cox regression analysis indicated that postoperative adjuvant chemotherapy [hazard ratio (HR) =0.45; 95% confidence interval (CI): 0.24-0.85] was significantly associated with improved OS, whereas a smoking index exceeding 400 (HR =1.0011; 95% CI: 1.0004-1.0018) was identified as an independent adverse prognostic factor. Pathological stratification showed that prophylactic cranial irradiation (PCI) was significantly associated with improved OS in stage II/III patients (P<0.05) but had not in stage I patients (P>0.05). Regarding DFS, preoperative neoadjuvant chemotherapy was associated with significantly prolonged DFS (HR =0.44; 95% CI: 0.21-0.94), while lymph node metastasis was identified as a negative predictor (HR =1.97; 95% CI: 1.16-3.36).

Conclusions: Surgical intervention combined with perioperative adjuvant therapy provides significant survival benefits for patients with SCLC. Notably, preoperative neoadjuvant chemotherapy and postoperative adjuvant chemotherapy were associated with prolonged DFS and OS. For early-stage patients, the application of PCI should be approached cautiously. Further prospective studies are warranted to better balance its potential risks and benefits.

Keywords: Small-cell lung cancer (SCLC); disease-free survival (DFS); overall survival (OS); perioperative adjuvant therapy; surgical intervention.

Figure 1

OS curves of grouping variables with statistical significance in univariate Cox regression. Kaplan-Meier survival curves for the OS of patients with SCLC who underwent surgical treatment. Subgroup analyses were performed for key prognostic factors identified in the univariate Cox regression, including (A) postoperative chemotherapy, (B) pathological lymph node status, (C) PCI, (D) smoking index, and (E) pathological staging. Chemotherapy and PCI: 0, no; 1, yes. OS, overall survival; PCI, prophylactic cranial irradiation; SCLC, small-cell lung cancer.

Figure 2

Kaplan-Meier survival curves for OS based on PCI and pathological stage. Kaplan-Meier survival curves for the OS of patients with SCLC stratified by PCI status and pathological stage. Subgroup analyses were performed based on (A) stage I (n=43) and (B) stages II and III (n=78). PCI: 0, no; 1, yes. OS, overall survival; PCI, prophylactic cranial irradiation; SCLC, small-cell lung cancer.

Figure 3

DFS curves of grouping variables with statistical significance in univariate Cox regression. Kaplan-Meier survival curves for the DFS of patients with SCLC who underwent surgical treatment. Subgroup analyses were performed for key prognostic factors identified in the univariate Cox regression, including (A) preoperative neoadjuvant chemotherapy and (B) pathological lymph node status. Neoadjuvant chemotherapy: 0, no; 1, yes. DFS, disease-free survival; N, node; SCLC, small-cell lung cancer.