Exploration of immunotherapy in advanced pulmonary lymphoepithelioma-like carcinoma

Pulmonary squamous cell carcinoma and lymphoepithelial carcinoma - morphology, molecular characteristics and differential diagnosis

Squamous cell carcinoma (SCC) comprises one of the major groups of non-small-cell carcinoma of the lung, and is subtyped into keratinising, non-keratinising and basaloid SCC. SCC can readily be diagnosed using histomorphology alone in keratinising SCC. Confirmatory immunohistochemical analyses should always be applied in non-keratinising and basaloid tumours to exclude differential diagnoses, most prominently adenocarcinoma and high-grade neuroendocrine carcinoma, which may have important therapeutic consequences. According to the World Health Organisation (WHO) classification 2015, the diagnosis of SCC can be rendered in resections of morphologically ambiguous tumours with squamous immunophenotype. In biopsies and cytology preparations in the same setting the current guidelines propose a diagnosis of 'non-small-cell carcinoma, favour SCC' in TTF1-negative and p40-positive tumours to acknowledge a possible sampling bias and restrict extended immunohistochemical evaluation in order to preserve tissue for molecular testing. Most SCC feature a molecular 'tobacco-smoke signature' with enrichment in GG > TT mutations, in line with the strong epidemiological association of SCC with smoking. Targetable mutations are extremely rare but they do occur, in particular in younger and non- or light-smoking patients, warranting molecular investigations. Lymphoepithelial carcinoma (LEC) is a poorly differentiated SCC with a syncytial growth pattern and a usually prominent lymphoplasmacytic infiltrate and frequent Epstein-Barr virus (EBV) association. In this review, we describe the morphological and molecular characteristics of SCC and LEC and discuss the most pertinent differential diagnoses.

Clinical significance of baseline Epstein-Barr virus DNA for recurrent or metastatic primary pulmonary lymphoepithelioma-like carcinoma

Background: This study aimed to evaluate the clinical significance of baseline Epstein-Barr virus (EBV) DNA in recurrent or metastatic primary pulmonary lymphoepithelioma-like carcinoma (PLELC). Methods: 75 patients with baseline EBV DNA were included. The relationships between baseline EBV DNA and clinical characteristics, survival and objective response rate were analyzed. Results: The baseline EBV DNA levels were related to the liver, chest wall, distant lymph node(s) or multiple sites of distant metastasis. The high baseline EBV DNA group (≥41,900 copies/ml) was related to shorter progression-free and overall survival in univariate analysis and remained significant for progression-free survival in multivariate analysis. Conclusion: The baseline EBV DNA is a valuable biomarker for predicting prognosis and reflecting tumor burden in recurrent or metastatic PLELC.

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.