Metastatic index of non-small-cell lung cancer and long-term survival

Abstract

Aim

We aimed to determine whether metastatic index is a factor determining long-term survival in patients undergoing curative resection for non-small-cell lung cancer.

Methods

There were 2695 consecutive pulmonary resections performed between October 2001 and September 2011 in our institution; 1795 were potentially curative resections for non-small-cell lung cancer with bronchial margin length data available. Benchmarking against the International Association for the Study of Lung Cancer data set was performed. Cox multivariate analysis was undertaken. Metastatic index was defined as N stage× bronchial resection margin length.

Results

Benchmarking failed to reveal any significant differences between our data and the International Association for the Study of Lung Cancer data set. Univariate analysis identified metastatic index as a significant factor determining long-term survival (p = 0.04). Cox regression demonstrated that metastatic index (hazard ratio 1.29, p = 0.0002), age (hazard ratio 1.02, p < 0.0001), body mass index (hazard ratio 0.98, p = 0.006), female sex (hazard ratio 0.65, p < 0.0001), T1 stage (hazard ratio 0.67, p < 0.0001), T2 stage (hazard ratio 2.13, p < 0.0001), T3 stage (hazard ratio 1.59, p = 0.03), forced expiratory volume in 1 s (hazard ratio 0.70, p < 0.0001), pneumonectomy (hazard ratio 1.43, p = 0.001), histology subtype adenosquamous (hazard ratio 3.77, p = 0.01) and squamous (hazard ratio 0.83, p = 0.03) were all significant determinants of long-term survival.

Conclusion

Metastatic index is a significant factor determining long-term survival in patents with adenocarcinoma undergoing potentially curative surgery with a lobectomy.