Abstract 232P
Background
The study focuses on the phenomenon of tumor cells spreading through air spaces (STAS), a known prognostic factor in various lung cancers. Given the limited data on its impact in pulmonary lymphoepithelial carcinoma (PLEC), this research aims to explore how STAS influences clinical outcomes in PLEC patients.
Methods
In this retrospective study, 56 cases of surgically resected pulmonary lymphoepithelial carcinomas were examined. The presence of tumor cells within air spaces in the lung parenchyma beyond the edge of the tumor was used to define STAS, while artifacts were excluded. The analysis of Recurrence-Free Survival (RFS) was conducted using the log-rank test and the Cox proportional hazards model.
Results
In our review, STAS was identified in 18 of the 56 patients (32.1%). It correlated with larger tumor sizes (over 3cm) (p=0.009), an elevated pathologic stage (p=0.026), and the presence of tumor necrosis (p=0.046). The 5-year RFS rate was notably lower for patients with STAS (p=0.025). Furthermore, a multivariate analysis indicated that STAS independently predicted a reduced RFS, with a hazard ratio of 3.395 (p=0.038). There was also a marked increase in the risk of locoregional recurrence for patients exhibiting STAS (p=0.049). Given these insights, we suggest a novel 3-tier grading system, taking into account tumor border patterns and STAS, to more accurately forecast the 5-year RFS for PLEC patients. Table: 232P
| Characteristic | Multivariate analysis | ||
| HR | 95%CI | P | |
| Smoker, never vs former/current | 1.339 | 0.288-6.227 | 0.709 |
| Tumor size 3 vs >3cm | 1.409 | 0.266-7.461 | 0.687 |
| Stage, I vs II | 2.068 | 0.436-9.820 | 0.361 |
| I vs III | 6.494 | 1.401-30.113 | 0.017 |
| Visceral pleural invasion | 1.420 | 0.362-5.565 | 0.615 |
| Tumor necrosis | 0.980 | 0.257-3.740 | 0.977 |
| Granulomatous inflammation | 2.795 | 0.882-8.855 | 0.081 |
| STAS | 3.395 | 1.072-10.750 | 0.038 |
Conclusions
The study introduces a 3-tier grading system based on tumor border patterns and STAS to predict 5-year RFS in resected PLEC. It highlights STAS as an independent predictor of poor RFS, confirming the system's effectiveness in forecasting clinical outcomes in PLEC patients.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.