Effectiveness of Postoperative or Preoperative Radiotherapy on Prognosis in Patients with Stage II Resectable Non-Small Cell Lung Cancer: A Retrospective Study Based on the SEER Database

Lymph node ratio predicts overall survival in patients with stage II non-small cell lung cancer: a population-based SEER analysis

BACKGROUND

In non-small-cell lung cancer (NSCLC), there are many factors that affect prognosis, and the lymph node ratio (LNR) may play a significant role. Our study aimed to confirm the value of the LNR in the prognosis of patients with stage II NSCLC.

METHODS

Patient data were obtained from the Surveillance, Epidemiology and End Results (SEER) database. The classification for the LNR was best determined using the X-tile method. The correlation between the LNR and overall survival (OS) was validated after the Kaplan-Meier analysis was performed. To determine the correlation between the LNR and survival, stratification and the Cox regression analysis were used.

RESULTS

In our study, 14,183 stage II NSCLC patients were included. Among them, 8303 patients had N1 disease. According to the X-tile analysis, the optimal critical points for the LNR in N1 patients with NSCLC was 0.21 and 0.38. We categorized the cohorts as low (LNR-L ≤ 0.21; n = 5158, 62.1%), medium (0.21 < LNR-M ≤ 0.38; n = 1736, 20.9%), and high (LNR-H > 0.38; n = 1409, 17.0%). According to the Kaplan-Meier analysis, the patients with a high LNR were considerably worse than those with a medium or low LNR (P < 0.001), which was also proven by stratified and multivariate analyses. The value of the LNR was reflected in all the subgroup analyses, especially in patients ages < 60 years. The multivariate competing risks regression analysis revealed that younger age, female sex, T1 disease, adenocarcinoma and N0 disease was associated with a better prognosis after controlling for potential confounders (P < 0.001).

CONCLUSIONS

For patients with stage II NSCLC, the LNR is valuable for assessing prognosis. A higher LNR indicates a worse prognosis.

Expression and Clinical Significance of Serum Krüppel-Like Factor 7 (KLF7) in NSCLC Patients

Nonsmall cell lung cancer (NSCLC) is a serious threat to the life and health of patients with high incidence rate and mortality. The present research was to assess the relationship between the serum Krüppel-like factor 7 (KLF7) level and the recurrence and metastasis of NSCLC patients. 150 patients with NSCLC treated by thoracoscopic radical resection of lung cancer in our hospital from January 2016 to February 2017 were selected. As the control group, 148 healthy people who went to the hospital for physical examination in the same period were screened. The expression levels of serum KLF7 in the observation group and the control group were compared and analyzed. According to the level of KLF7 expression, the patients in the observation group were divided into KLF7 high expression group (≥258.6 ng/L, n =75) and KLF7 low expression group (<258.6 ng/L, n =75). The 3-year recurrence and metastasis rate of patients in each group was compared and analyzed. It was found the concentration of serum KLF7 in peripheral blood of NSCLC (2.25 ± 0.65) ng/ml was significantly higher than that in healthy population (1.42 ± 0.38) ng/ml (P < 0.05). The expression level of serum KLF7 was not related to gender, age, smoking history, and tumor diameter of NSCLC patients (P > 0.05), but related to the degree of differentiation and TNM stage of NSCLC patients (P < 0.05). Univariate analysis showed that the degree of differentiation, TNM stage, and KLF7 were significantly correlated with 3-year recurrence and metastasis of NSCLC patients (P < 0.05). Cox regression analysis showed that low degree of differentiation, TNM stage IIIa, and KLF7 were independent risk factors for recurrence and metastasis in NSCLC patients in 3 years (P < 0.05). Taken together, the expression level of serum KLF7 in patients with NSCLC is significantly increased, which is an independent risk factor for recurrence and metastasis in 3 years, and is worthy of clinical application.