Survival with Parenchymal and Pleural Invasion of Non-Small Cell Lung Cancers Less than 30 mm

Abstract

Objective: To determine long-term survival of visceral pleural invasion (VPI) and parenchymal invasion (PAI) (angiolymphatic and/or vascular) on survival of NSCLCs less than 30 mm in maximum diameter.

Methods: Kaplan-Meier survivals for NSCLCs, with and without VPI and/or PAI, were determined for a prospective cohort of screening participants stratified by pathologic tumor size (≤10 mm, 11-20 mm, and 21-30 mm) and nodule consistency. Log-rank test statistics were calculated.

Results: The frequency of PAI versus VPI was significantly lower in patients with subsolid nodules than in those with solid nodules (4.9% versus 27.7% [p < 0.0001]), and correspondingly, Kaplan-Meier lung cancer survival was significantly higher among patients with subsolid nodules (99.1% versus 91.3% [p = 0.0009]). Multivariable Cox regression found that only tumor diameter (adjusted hazard ratio [HR] =1.07, 95% confidence interval [CI]: 1.01-1.14, p = 0.02) and PAI (adjusted HR = 3.15, 95% CI: 1.25-7.90, p = 0.01) remained significant, whereas VPI was not significant (p = 0.15). When clinical and computed tomography findings were included with the pathologic findings, Cox regression showed that the risk of dying of lung cancer increased 10-fold (HR = 10.06, 95% CI: 1.35-75.30) for NSCLCs in patients with solid nodules and more than twofold (by a factor of 2.27) in patients with moderate to severe emphysema (HR = 2.27, 95% CI: 1.01-5.11), as well as with increasing tumor diameter (HR = 1.06, 95% CI: 1.01-1.13), whereas PAI was no longer significant (p = 0.19).

Conclusions: Nodule consistency on computed tomography was a more significant prognostic indicator than either PAI or VPI. We propose that patients with NSCLC with VPI and a maximum tumor diameter of 30 mm or less not be upstaged to T2 without further large, multicenter studies of NSCLCs, stratified by the new T status and that classification be considered separately for patients with subsolid or solid nodules.

Keywords: Lung cancer survival; Lymphatic; Pleural; Small lung cancers; Vascular invasion.