Abstract 1323: 12-chemokine gene signature identifies major pathologic response in patients with hepatocellular carcinoma treated with neoadjuvant nivolumab and cabozantinib

Abstract Background: Tertiary lymphoid structures (TLS) are ectopic lymphoid organs that develop at sites of chronic inflammation. In many solid tumors they have been linked with improved survival, but their prognostic value in hepatocellular carcinoma (HCC) remains uncertain. In immunotherapy-naïve patients with HCC, peritumoral and intratumoral TLS have been associated with improved overall survival, but TLS and increased expression of an associated 12-chemokine gene signature in tumor-adjacent liver parenchyma have also been linked to worse outcomes. In patients with HCC receiving immunotherapy, the prognostic value of TLS and the 12-chemokine signature is not known. Methods: We collected formalin-fixed, paraffin-embedded tumors of 12 patients with locally advanced HCC treated with neoadjuvant nivolumab and cabozantinib followed by surgical resection. We used immunohistochemistry and imaging mass cytometry to determine TLS density and immunophenotype. We obtained bulk RNA sequencing from 9 patients (4 responders and 5 non-responders) and used hierarchical clustering to define subgroups of patients according to expression of a previously validated 12-chemokine gene signature. The prognostic value of the chemokine signature for predicting disease free survival (DFS) was calculated using the Kaplan-Meier method and analyzed by log-rank test. Additional analysis of the spatial heterogeneity of the 12-chemokine signature was performed using spatial transcriptomics. Results: Increased TLS density was associated with a major pathologic response to treatment (p = 0.006). Hierarchical clustering of expression of the 12-chemokine gene signature identified increased expression in 4 responders and 1 non-responder and decreased expression in 4 non-responders. The association between chemokine expression and pathologic response to treatment was statistically significant by Fisher’s exact test (p = 0.008). Patients with increased expression of the 12-chemokine signature showed a trend toward improved DFS (HR = 0.23, 95% CI 0.03 to 3.05). Spatial transcriptomics showed heterogeneous chemokine expression across the resection specimen which was highest in immune clusters. Conclusions: Using immunohistochemistry, bulk RNA sequencing, and spatial transcriptomics, we show that TLS and a TLS-associated 12-chemokine gene signature are associated with a favorable response to treatment in patients receiving neoadjuvant nivolumab and cabozantinib for HCC. We found a trend toward improved DFS in patients with increased expression of the 12-chemokine signature, a finding which should be evaluated in a larger cohort. Further research is necessary to determine the functional role of TLS in anti-tumor immunity. Citation Format: Daniel H. Shu, Ludmila Danilova, Long Yuan, Qingfeng Zhu, Hao Wang, Luciane Kagohara, Robert Anders, Elizabeth Jaffee, Elana Fertig, Mark Yarchoan. 12-chemokine gene signature identifies major pathologic response in patients with hepatocellular carcinoma treated with neoadjuvant nivolumab and cabozantinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1323.