Capecitabine in pretreated metastatic pulmonary lymphoepithelioma-like carcinoma: A retrospective study.

Abstract

9093 Background: Pulmonary lymphoepithelioma-like carcinoma (LELC) is a rare disease, sharing common histological features with the undifferentiated subtype of nasopharyngeal carcinoma (NPC), and being under-represented in non-small cell lung cancer trials and clinical guidelines. While gemcitabine-based platinum doublet chemotherapy is more established in 1st line treatment of stage IV disease, there is limited evidence for subsequent treatment strategy. Oral capecitabine is one of the active agents in metastatic NPC, and was observed to have encouraging outcomes in pulmonary LELC. Methods: All consecutive patients with pulmonary LELC in 2010 – 2019 treated in a tertiary institution were reviewed. Patients with metastatic disease who progressed after gemcitabine-based platinum doublets and treated with capecitabine were included. Capecitabine was given at 1250 mg/m2 twice daily for 14 days followed by 7 days of rest in each cycle. Treatment response was monitored by clinical history, physical examination and imaging. Treatment was continued till drug holiday, intolerance or disease progression. Progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Clinical predictors for PFS and OS were analyzed using log-rank test and the Cox proportional hazard model. Results: Of the 140 LELC patients identified, 36 patients satisfied the above inclusion criteria (14 male, 22 female). Median age was 58.6 years old (range 41.5 – 75.6). All patients had an ECOG performance score of 0 or 1. 16 patients (44.4%) received 2 or more lines of prior systemic treatment. Median capecitabine cycles received was 5 (range 2 – 68). Objective response rate was 27.8% (complete response: 5.6%; partial response: 22.2%), disease control rate was 75.0%. With a median follow-up of 15.3 months (range 1.8 – 82.6), the median PFS and OS were 5.4 months (95% CI, 2.1 – 8.8) and 15.4 months (95% CI, 10.0 – 20.7) respectively. Capecitabine was generally well tolerated, with 22.2% grade 3 or above side effects, and 5.6% treatment termination due to intolerance. Bone and distant lymph node (LN) involvement were significant predictors of poorer PFS on multivariate analyses (bone: HR 3.24, 95% CI 1.44 – 7.29, p=0.004; distant LN: HR: 2.62, 95% CI 1.14 – 6.02, p=0.024). Age, sex, smoking history, number of treatment lines, and other sites of disease involvement were not significant predictors. Conclusions: This is to date the largest reported cohort of capecitabine in pre-treated metastatic pulmonary LELC. Capecitabine is effective and well tolerated, and should be considered as a treatment option after 1st line platinum-based chemotherapy. Future studies are warranted to delineate the optimal treatment pathway of this rare disease entity.