Real-life experience of rare hepatoid adenocarcinomas of the lung: A large retrospective french cohort.

Abstract

e21091 Background: Hepatoid adenocarcinoma of the lung (HAL) is a rare subtype of lung cancer exhibiting common histological features with hepatocellular carcinomas (HCC). Therapeutic landscape is currently similar to lung adenocarcinoma standards. We report here the largest descriptive cohort of HAL with focus on (chemo)-immunotherapy (CT-IO) efficacy. Methods: In this single-center retrospective observational study, we selected all consecutive cases of HAL patients from January 2013 to January 2022. Eligible patients had primary lung tumor with positive immunohistochemical hepatocyte marker. HCC was eliminated with liver imaging. We provide a descriptive analysis of HAL population and describe our therapeutic experience. Results: A total of 21 patients were included. Main characteristics at diagnosis were: median age of 63 years [41-81], 80,9% of males, with 76,2% of PS 0-1. All patients had smoking history, with 8 active smokers. Twenty patients (95,2%) had stage IV disease. Median number of metastatic sites was 2; 7 (33,3%) patients had brain metastases. PD-L1 status was < 1% (n = 10), 1-5% (n = 2), ≥50% (n = 5), unknown (n = 4). Six (28,6%) patients harbored KRAS mutation: G12C (n = 4), G60D (n = 1), G12V (n = 1). One patient had Lynch syndrome with MMR deficiency. Median follow-up was 5 months. Median overall survival (mOS) since diagnosis achieved 9 months (95% CI, 3 to 21). Early palliative care concerned 6 patients. Five patients received first-line CT-IO. Best response was: partial response (n = 3), stable disease (n = 1), progressive disease (n = 1). One patient treated with first-line pembrolizumab achieved stable disease. Four patients received second-line IO but experienced early progressive disease. Conclusions: Our results highlighted the aggressive metastatic profile of HAL accounting for the poor mOS of 9 months. Patients could benefit from upfront CT-IO but further studies are warranted to confirm it.