Correlation between radiologic feature and spread through air space in lung solid adenocarcinoma 30.0 mm or less in maximum diameter.

Purpose: Tumor spread through air space (STAS) is recognized as an important prognostic indicator for lung cancer patients. However, few studies have focused on radiologic features for predicting STAS in patients with small solid lung adenocarcinomas 30.0 mm or less in maximum diameter. We aim to determine predictors of STAS using demographics and pre-surgery CT features, and the correlation between CT-guided biopsy and STAS.

Methods: Retrospective study of 511 participants in the Mount Sinai Health System with first primary clinical stage IA solid adenocarcinoma ≤30.0 mm in maximum diameter who received surgical treatment. STAS-positive and STAS-negative patients were compared using Wilcoxon rank-sum test and Chi-squared/Fisher exact test. Significant predictors of STAS were identified using multivariable analyses.

Results: Of 511 patients with surgically resected solid ADCs ≤30.0 mm (42 % male, 58 % female, median age 70 years [IQR: 64-77]), STAS was present in 63 (12.3 %). Multivariable analyses showed STAS was significantly associated with distance to the mediastinal pleura (OR = 0.97; 95 % CI, 0.96-0.99; P < .001) and diaphragmatic pleura (OR = 0.99; 95 % CI, 0.99-1.00; P = .03), distal post-obstructive changes (OR = 0.2; 95 % CI, 0.1-0.5; P < .001) and vascular embedding (OR = 2.2; 95 % CI, 1.1-4.4; P = .02) after adjusting for age, sex and smoking. No significant relationship was found between preoperative CT-guided biopsy and STAS presence.

Conclusion: Among solid ADCs ≤30.0 mm, distance to the mediastinal and diaphragmatic pleura, vascular embedding and distal post-obstructive changes were significant radiologic predictors of STAS. No significant difference existed in frequency of STAS between patients with and without pre-operative CT-guided biopsy, reducing concerns about its impact on STAS.