Characterization of outcomes and genomic alterations (GA) in combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA).

Abstract

458 Background: Hepatobiliary cancers comprise a heterogeneous spectrum of invasive carcinomas involving the liver and bile ducts. Due to its rarity, the prognosis and clinical outcomes data are poorly understood. This study aims to provide insight into the response to therapeutic options and GA in patients (pts) with cHCC-CCA. Methods: We conducted a retrospective analysis of clinical outcomes data and GA at MD Anderson (MDA) from 2009 to 2023 in pts with cHCC-CCA. Pt characteristics were compared using Fisher’s exact test and Mann-Whitney U. Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier and the log-rank test. Results: 40 pts with cHCC-CCA were analyzed. Hepatitis B and C were the most common etiologies (Table). 25.0% had portal vein tumor thrombus and 72.0% had advanced disease (M1/N1) at diagnosis. Radiographic washout was seen in 55.9%. Elevation of CA19-9, AFP, and both was in 42.5, 57.5, and 30.0%. Cirrhosis at diagnosis was 35.0%. Pts who underwent surgery (n=10) had significant OS benefit (55.6 vs. 14.1 m, p<0.001). Y90 (n=4)/radiation therapy (n=10) provided significant OS benefit in pts who did not undergo surgery (23.3 vs 10.9 m; p=0.012). 34 pts received 1st line systemic therapy: 10 pts received gemcitabine/cisplatin (GC) combined with immunotherapy (GCI): GC + nivolumab (n=5), durvalumab (n=3), or atezolizumab/bevacizumab (AB, n=2). GCI was compared to other regimens (OR, n=24) including chemotherapy alone (GC, FOLFIRI, FOLFOX), HCC-directed therapy alone (AB, lenvatinib, nivolumab), or chemotherapy plus lenvatinib or bevacizumab with mPFS of 7.0 vs. 2.9 m (p=0.014) showing significant PFS benefit. Pts who received GCI trended to better OS compared to OR (18.9 vs. 12.0 m, p=0.380). 2 pts treated with GC+AB had complete responses to date at 36.0 and 14.0 m. Of 31 pts who underwent GA testing, the 2 most frequent GAs were TP53 (38.7%) and TERT (35.5%) mutations. Neither impacted OS: TP53 15.8 vs. 17.6 m (p=0.746); TERT 9.8 vs. 23.3 m (p=0.355). Conclusions: GCI had survival benefit compared to OR in cHCC-CCA. Pts who present with early stage of disease should be evaluated early for surgical resection or maximize local therapy in the case of nonresectable disease to improve survival. [Table: see text]