Prognostic factors of patients with small cell lung cancer after surgical treatment

The current National Comprehensive Cancer Network guidelines recommend surgical treatment for patients with stages I-IIA small cell lung cancer (SCLC), but it still cannot deny the effect of surgical treatment on other limited-stage SCLC. Although more advanced diagnostic methods are now used for the diagnosis and classification of SCLC, the selection of surgical candidates is still arbitrary.

Data were collected from patients with SCLC who underwent surgery at the First Affiliated Hospital of Zhengzhou University from January 2011 to January 2021. Kaplan-Meier method was used to calculate cumulative survival curves, and log-rank test was used to evaluate differences among different subgroups. The Cox proportional hazard regression model was used to assess the predictive power of the variables for prognosis and survival.

Smoking index, surgical resection method, TNM stage of postoperative pathology, and postoperative chemotherapy were significantly correlated with postoperative survival (P<0.05), which were independent predictors for postoperative survival. Patients with a smoking index >800 had a higher risk of death after surgery [hazard ratio (HR): 7.050, 95% confidence interval (CI): 3.079-16.143, P<0.001]. Compared with patients who underwent pulmonary lobectomy, those who underwent other pneumoresections (e.g., wedge resection, segmental resection, sleeve resection) had an increased risk of death (HR: 2.822, 95% CI: 1.030-7.734, P=0.044). Compared with stage I patients, stage II and stage III patients had an increased risk of death, with HRs of 6.039 and 3.145, respectively. Compared with those who received ≤4 courses of postoperative chemotherapy, those who received >4 courses of postoperative chemotherapy had reduced postoperative mortality risk (HR: 0.211, 95% CI: 0.097-0.459, P<0.001).

A high smoking index suggests worse prognosis; therefore, patients who smoke should be advised to quit smoking. Compared with stage II and stage III patients, surgical treatment is recommended for stage I SCLC patients. TNM staging, especially N staging, should be evaluated prior to surgery. Pulmonary lobectomy with mediastinal lymph node dissection should be the preferred surgical treatment for patients with SCLC. Patients should receive at least 5 courses of adjuvant chemotherapy after surgery.