Prognostic Significance of Visceral Pleural Involvement in Early Stage Lung Cancer.
Lakha S, Gomez JE, Flores RM, Wisnivesky JP.
Chest. 2014 Jul 17. doi: 10.1378/chest.14-0204.
Visceral pleural invasion (VPI) may impact non-small cell lung cancer (NSCLC) survival. However, previous studies are mixed as to whether VPI is an independent prognostic factor in early-stage cancers, and whether its effect is size-dependent. In the current American Joint Committee on Cancer (AJCC) staging system, VPI leads to upstaging of cancers <3 cm but not of those 3-7 cm in size.
Using the Surveillance, Epidemiology, and End Results registry, we identified 16,315 patients with stage I-II NSCLC treated with lobectomy. We used the Kaplan-Meier method and Cox regression to assess the association of VPI with lung-cancer specific (primary outcome) and overall survival. Based on these results we created a revised VPI staging classification.
Overall, 3,389 (21%) patients had VPI. Kaplan-Meier analysis stratified by tumor size showed worse cancer-specific survival in patients with VPI (p<0.0001). VPI was independently associated with decreased lung cancer-specific survival (hazard ratio: 1.38, 95% confidence interval: 1.29-1.47) after controlling for tumor size and other confounders; this effect was not size-dependent. In our revised classification, tumors <7 cm with VPI were upstaged to the next T category.
VPI is a prevalent finding associated with worse prognosis in early-stage lung cancer even among patients with tumors >3 cm in size, a factor not captured in the current staging system. Patients with VPI may be considered candidates for more aggressive treatment.