A Rare Subtype of Non-small Cell Lung Cancer: Report of 159 Resected Pathological Stage I-IIIA Pulmonary Lymphoepithelioma-Like Carcinoma Cases

Tumor Spread Through Air Spaces Predicts Survival in Resected Pulmonary Lymphoepithelial Carcinoma

BACKGROUND

Tumor spread through air spaces (STAS) has been recognized as a prognostic factor for several types of lung cancers. However, information regarding its clinical significance in pulmonary lymphoepithelial carcinoma is limited. Therefore, this study investigated effects of STAS on the clinical outcomes for patients with pulmonary lymphoepithelial carcinoma.

METHODS

This study retrospectively reviewed 56 surgically resected pulmonary lymphoepithelial carcinomas. The study defined STAS as the presence of tumor cells within air spaces in lung parenchyma beyond the tumor edge. Artifacts were excluded. Recurrence-free survival (RFS) was analyzed using the log-rank test and Cox proportional hazards model.

RESULTS

In 18 patients (32.1%), STAS was observed and found to be associated with larger tumor size (>3 cm) (p = 0.009), higher pathologic stage (p = 0.026), and tumor necrosis (p = 0.046). Patients with STAS had a significantly lower 5-year RFS rate (p = 0.025). Multivariate analysis showed that STAS was an independent predictor of worse RFS (hazard ratio, 3.395; p = 0.038). Patients with STAS had a significantly increased risk of locoregional recurrence (p = 0.049).

CONCLUSIONS

The study findings suggest that STAS is an independent predictor of poor RFS. Based on these findings, a new three-tier grading system based on the patterns of tumor border and STAS was proposed for effective prediction of 5-year RFS in pulmonary lymphoepithelial carcinoma.

Development of a nomogram based on the clinicopathological and CT features to predict the survival of primary pulmonary lymphoepithelial carcinoma patients

BACKGROUND

The aim of this study was to develop a nomogram by combining chest computed tomography (CT) images and clinicopathological predictors to assess the survival outcomes of patients with primary pulmonary lymphoepithelial carcinoma (PLEC).

METHODS

113 patients with stage I-IV primary PLEC who underwent treatment were retrospectively reviewed. The Cox regression analysis was performed to determine the independent prognostic factors associated with patient's disease-free survival (DFS) and cancer-specific survival (CSS). Based on results from multivariate Cox regression analysis, the nomograms were constructed with pre-treatment CT features and clinicopathological information, which were then assessed with respect to calibration, discrimination and clinical usefulness.

RESULTS

Multivariate Cox regression analysis revealed the independent prognostic factors for DFS were surgery resection and hilar and/or mediastinal lymphadenopathy, and that for CSS were age, smoking status, surgery resection, tumor site in lobe and necrosis. The concordance index (C‑index) of nomogram for DFS and CSS were 0.777 (95% CI: 0.703-0.851) and 0.904 (95% CI: 0.847-0.961), respectively. The results of the time‑dependent C‑index were internally validated using a bootstrap resampling method for DFS and CSS also showed that the nomograms had a better discriminative ability.

CONCLUSIONS

We developed nomograms based on clinicopathological and CT factors showing a good performance in predicting individual DFS and CSS probability among primary PLEC patients. This prognostic tool may be valuable for clinicians to more accurately drive treatment decisions and individualized survival assessment.

N6-methyladenosine methylation regulatory pattern of pulmonary lymphoepithelioma-like carcinoma based on exosomal transcriptome analysis

Pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare malignancy that lacks specific biomarkers. N6-methyladenosine (m6 A) is the most widespread internal modification of messenger RNA (mRNA), and its dysregulation is involved in the development of many cancers. However, the expression of m6 A genes in pLELC and their roles are unknown. We obtained an exosomal transcriptome data set of patients diagnosed with pLELC and healthy controls using RNA sequencing and identified differentially expressed genes (DEGs) in the two groups using R software. The differential expression of the 37 m6 A genes in the two sets of samples was further analyzed, and receiver operating characteristic (ROC) curves were plotted for each gene to identify their grouping ability. The STRING database was used to construct a protein-protein interaction network for m6 A genes. An mRNA-miRNA regulatory network of m6 A-related DEGs was constructed using the miRNet database, and a prediction score formula was established. A nomogram was constructed based on the candidate m6 A genes and prediction scores. The expression of key genes was determined through the immunohistochemical (IHC) staining of clinical tissue sections. Using ROC curves, nine m6 A genes were revealed to have classification efficacy in both groups of samples. We screened seven m6 A-related DEGs (MAN2C1, HNRNPCL1, FUS, EIF6, DIP2A, COA3, and BUD13) that were beneficial for grouping and constructed nomogram models. Through IHC, we identified FUS and EIF6 as being possibly involved in the occurrence and development of pLELC. The m6 A gene expression patterns in pLELC-derived exosomes were significantly different from those in healthy controls. We screened several key genes to facilitate the development of diagnostic markers for pulmonary lymphoepithelioma.

Treatment options for stage III-N2 pulmonary lymphoepithelioma-like carcinoma: A retrospective cohort study

BACKGROUND AND PURPOSE

Pulmonary lymphoepithelioma-like carcinoma (PLELC) is a rare form of non-small cell lung carcinoma (NSCLC) that shares similarities with nasopharyngeal carcinoma. The optimal treatment for stage III-N2 PLELC remains controversial.

METHODS AND MATERIALS

We conducted a retrospective analysis from stage III-N2 PLELC patients between 2009 and 2022 in our center. The patients were categorized into three groups: Group 1 (G1, definitive chemoradiotherapy), Group 2 (G2, radical surgery plus adjuvant chemoradiotherapy), and Group 3 (G3, radical surgery plus adjuvant chemotherapy).

RESULTS

A total of 103 patients were included in the study, with 34, 25, and 44 patients in G1, G2, and G3, respectively. The median follow-up time was 47.4 months. The overall median PFS was 66.6 months, with 3-year PFS and 3-year OS rates of 66.0% and 92.4%, respectively, for all patients. Multivariate analysis revealed no significant difference in PFS between G1 and G2 (p = 0.354), while both groups exhibited significantly longer PFS than G3 (p < 0.001; p = 0.039). Similarly, no significant difference in OS was observed between G1 and G2 (p = 0.649), but both tended to demonstrate improved OS compared to G3 (p = 0.081; p = 0.092). Only one case of grade 3 radiation esophagitis was observed in G1, and no grade 3 or higher radiation pneumonitis were reported.

CONCLUSIONS

Patients with stage III-N2 PLELC have a favorable prognosis, with radiotherapy playing a crucial role in treatment. Both definitive chemoradiotherapy and radical surgery followed by chemoradiotherapy demonstrate favorable efficacy and manageable toxicity.

Primary pulmonary lymphoepithelioma-like carcinoma misdiagnosed as lung squamous cell carcinoma: A case report

BACKGROUND

Primary pulmonary lymphoepithelioma-like carcinoma (PPLELC) is an uncommon subtype of squamous cell carcinoma (SCC) of the lung, closely associated with Epstein-Barr virus (EBV) infection. The pathological features of PPLELC closely resemble those of SCC, which makes it prone to misdiagnosis. Surgical intervention constitutes the primary treatment approach for PPLELC.

CASE SUMMARY

This report describes a 44-year-old woman who was hospitalized for 1 mo due to left chest pain. Computed tomography revealed a mass shadow in the anterior basal segment of the left lower lobe, and a subsequent needle biopsy suggested SCC. The patient underwent radical tumor resection in the lower left lobe of the lung, and postoperative pathological examination indicated lymphoepithelial carcinoma, and the test for EBV encoded small RNA was positive. Following surgery, the patient was scheduled to receive four cycles of adjuvant chemotherapy, using the paclitaxel + carboplatin regimen, but the patient refused further treatment.

CONCLUSION

PPLELC is an exceptionally rare subtype of lung SCC and is prone to misdiagnosis.

Clinicopathological features and survival of rare primary pulmonary lymphoepithelial carcinoma: A cohort from a single center

BACKGROUND

Primary pulmonary lymphoepithelial carcinoma (PLEC) is a rare subtype of nonsmall cell lung cancer. This study aimed to investigate the clinicopathological and prognostic characteristics of resected primary PLEC.

MATERIALS AND METHODS

In this retrospective study, 95 consecutive patients with primary PLEC, who received radical surgical resection treatment, were examined from October 2009 to January 2022. The clinicopathological features and their association with survival outcomes were analyzed.

RESULTS

Primary PLEC predominated in relatively younger patients and nonsmokers, who lacked driver mutations and were always positive for immunohistochemical markers of the squamous cell lineage. Further, 21.1% of patients had abnormally elevated preoperative serum marker fragments of cytokeratin 19 (Cyfra21-1). The median follow-up time was 43.5 months. The 1-, 3-, and 5-year recurrence-free survival (RFS) rates were 96.5%, 81.8%, and 64.3%, respectively. The median RFS time was not reached. Cox univariate survival analysis showed that patients with positive lymph nodes had significantly worse RFS than those with negative ones (p = 0.017). The patients with open surgery experienced significantly worse RFS than those with video-assisted thoracoscopic surgery (p = 0.038). The multivariate survival analysis confirmed that only lymph node involvement (hazard ratio: 2.769; 95% confidence interval: 1.171-6.548, p = 0.020) was an independent prognostic factor.

CONCLUSIONS

Primary PLEC is a rare type of lung cancer with a favorable outcome, more common in young and nonsmoking Asian populations. Driver gene mutations are rare. Regional lymph node metastasis is an independent prognostic factor for RFS after radical surgical resection.