Prognostic value of visceral pleural invasion in the stage pT1-2N2M0 non-small cell lung cancer: A study based on the SEER registry

Abstract

BackgroundVisceral pleural invasion (VPI) is considered an adverse prognostic factor in non-small cell lung cancer (NSCLC). However, the prognostic roles of VPI in Ⅲ/N2 NSCLC remain controversial. Therefore, this study aims to evaluate the prognostic value of VPI in patients with postoperative stage pT1-2N2M0 NSCLC. MethodsUsing the Surveillance, Epidemiology, and End Results (SEER) database, we screened for patients with stage T1-2N2M0 NSCLC who received surgery from 2010 to 2015. To reduce baseline differences between Non-VPI group and VPI group, two-to-one propensity score matching (PSM) was performed. Cox proportional hazards regression was used to identify factors associated with survival. Overall survival (OS) was between the Non-VPI group and the VPI+ group by the Kaplan-Meier analysis. ResultsWe identified 1374 postoperative NSCLC patients with stage pT1-2N2M0. The majority of cases (N = 1047, 76.8%) are Non-VPI patients. The factors associated with VPI+ group included white race (P < 0.0001), and adenocarcinoma (P < 0.0001).When analyzed in the total study population, VPI status remained a significant independent predictor of worse OS compared with the Non-VPI group (HR, 1.343; 95% CI, 1.083–1.665 [P=0.007]). Besides, in a subgroup analysis by VPI status, the results showed that patients without treatment exhibited a higher risk level in the Non-VPI group (P<0.0001). However, we did not find statistically significant differences among treatments in the VPI+ group (P=0.199). Mean survival time was 49.5 months (95% CI: 45.7–53.3 months) for chemotherapy alone in the Non-VPI group, compared with 41.2 months (95% CI: 35.8–46.6 months) in VPI+ groups. In both the VPI group and the non-VPI group, there is no statistical difference between adjuvant chemotherapy combined with PORT and chemotherapy alone. ConclusionThis study emphasizes that the presence of VPI is a poor prognostic factor, even in patients with Ⅲ/N2 NSCLC. As the study shows, chemotherapy significantly improved overall survival of patients with postoperative stage pT1-2N2M0 NSCLC, especially for Non-VPI patients. However, the significance of PORT is still worth further exploration.