Risk factors and intraoperative identification of non-lepidic predominant lung adenocarcinoma presenting as subsolid nodule: A multicenter study

Abstract

Background

The purpose of this study was to assess the prognostic factors for non-lepidic invasive adenocarcinoma presenting as subsolid nodules. The feasibility of detecting non-lepidic predominant patterns on frozen section (FS) was also evaluated.

Methods

A multicenter retrospective cohort of 614 patients with clinical T1N0M0 non-lepidic invasive adenocarcinoma presenting as subsolid nodule was included. Two subgroups were divided based on the consolidation-to-tumor ratio (CTR) on lung window: ground glass opacity (GGO)-dominant subgroup (CTR<0.5), solid-dominant subgroup (CTR≥0.5). Kaplan-Meier approach and multivariable Cox models were used to identify risk factors for recurrence-free survival (RFS) and overall survival (OS). FS and final pathology (FP) of 100 specimens were also reviewed by five pathologists for tumor grading synchronously.

Results

Multivariate analysis indicated that segmentectomy was a risk factor for shortened RFS and OS in the solid-dominant subgroup rather than in the GGO-dominant one. Subset analysis demonstrated survival disadvantages of segmentectomy for high-grade adenocarcinoma but not for intermediate-grade one in the solid-dominant subgroup. However, segmentectomy exhibited non-inferiority to lobectomy in the GGO-dominant subgroup irrespective of tumor grade. The overall accuracy of identifying non-lepidic patterns was 84 % with a good interobserver agreement. Multivariable logistic analysis identified presence of complex glandular pattern and acinar pattern as independent predictors of the discrepancy between FS and FP.

Conclusions

Segmentectomy should be cautiously performed for patients with radiologically solid-dominant non-lepidic invasive adenocarcinoma, especially for those with high-grade patterns. FS had high diagnostic accuracy and satisfactory interobserver agreement for tumor grading, which might aid surgeons in determining the appropriate surgical procedure.