Postoperative recurrence of clinical early-stage non-small cell lung cancers: a comparison between solid and subsolid nodules

Shingo Iwano,Koji Kawaguchi,Takayuki Fukui,Hiroyasu Umakoshi,Kohei Yokoi,Shinichiro Kamiya,Shinji Naganawa

doi:10.1186/s40644-019-0219-3

Abstract

BackgroundFor subsolid non-small cell lung cancers (NSCLCs), solid size (SS), which is the maximal diameter of the solid component, correlates more accurately with tumor prognosis than the total size, which is the maximal diameter of the entire tumor, including ground-glass opacity. We reviewed the propriety of the TNM staging based on the SS for early-stage NSCLCs.MethodsWe retrospectively reviewed the preoperative radiological reports, clinical records, and pathological reports of NSCLC cases in our hospital between 2010 and 2013, and clinical stage (c-Stage) 0 and I tumors were selected. Disease-free survival (DFS), based on survival analysis, was used to assess the tumor characteristics that predicted the prognosis.ResultsA total of 247 NSCLC diagnoses in 231 patients (88 women and 143 men; age, 67 ± 7 years) were included in our cohort. They were classified into solid (n = 131) and subsolid (n = 116) nodules. The DFS curves indicated that prognosis was significantly worse in the following order: c-Stage 0, c-Stage IA, and c-Stage IB tumors (p = 0.016). Patients with solid nodules showed a significantly worse prognosis than patients with subsolid nodules (p < 0.001). A multivariate Cox proportional hazards model showed that the significant predictive factors for DFS were c-Stage (hazard ratio, 1.600; p = 0.020) and solid nodules (hazard ratio, 3.077; p = 0.031).ConclusionsFor early-stage NSCLCs, the c-Stage based on the SS in subsolid nodules was useful for predicting postoperative DFS. In addition, whether nodules were solid or subsolid was another independent prognostic factor.

Highlights

For subsolid non-small cell lung cancers (NSCLCs), solid size (SS), which is the maximal diameter of the solid component, correlates more accurately with tumor prognosis than the total size, which is the maximal diameter of the entire tumor, including ground-glass opacity
Some previous studies have focused on the solid component that reflects the intra-tumoral collapse of the airspace or fibrosis within the subsolid nodules and have demonstrated that the solid size (SS), which is the maximal diameter of the solid component, correlates with tumor invasiveness and patient prognosis [4,5,6,7]
We retrospectively evaluated whether the clinical staging based on the 8th version of the Union for International Cancer Control (UICC) could reflect the postoperative prognosis of patients with small NSCLC

Summary

Introduction

For subsolid non-small cell lung cancers (NSCLCs), solid size (SS), which is the maximal diameter of the solid component, correlates more accurately with tumor prognosis than the total size, which is the maximal diameter of the entire tumor, including ground-glass opacity. We reviewed the propriety of the TNM staging based on the SS for early-stage NSCLCs. It is well known that the prognosis of non-small cell lung cancer (NSCLC) with masses equal to or less than 3 cm in diameter is favorable [1, 2]. NSCLCs are classified clinically into solid nodules, including only solid components, and subsolid nodules, including ground-glass opacity (GGO) components, based on thin-section CT findings. The total size (TS) measurement, which is equal to the SS, has been adopted as before. A recent study by Hattori et al indicated that the presence of a GGO component in the tumor was an index of favorable prognosis [9, 10]

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Discussion

Conclusion