OncoImmunology (Feb 2017)

PD-L1, Galectin-9 and CD8+ tumor-infiltrating lymphocytes are associated with survival in hepatocellular carcinoma

  • Kostandinos Sideras,
  • Katharina Biermann,
  • Joanne Verheij,
  • Bart R. Takkenberg,
  • Shanta Mancham,
  • Bettina E. Hansen,
  • Hannah M. Schutz,
  • Robert A. de Man,
  • Dave Sprengers,
  • Sonja I. Buschow,
  • Maddy C. M. Verseput,
  • Patrick P. C. Boor,
  • Qiuwei Pan,
  • Thomas M. van Gulik,
  • Turkan Terkivatan,
  • Jan N. M. Ijzermans,
  • Ulrich H. W. Beuers,
  • Stefan Sleijfer,
  • Marco J. Bruno,
  • Jaap Kwekkeboom

DOI
https://doi.org/10.1080/2162402X.2016.1273309
Journal volume & issue
Vol. 6, no. 2

Abstract

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Novel systemic treatments for hepatocellular carcinoma (HCC) are strongly needed. Immunotherapy is a promising strategy that can induce specific antitumor immune responses. Understanding the mechanisms of immune resistance by HCC is crucial for development of suitable immunotherapeutics. We used immunohistochemistry on tissue-microarrays to examine the co-expression of the immune inhibiting molecules PD-L1, Galectin-9, HVEM and IDO, as well as tumor CD8+ lymphocyte infiltration in HCC, in two independent cohorts of patients. We found that at least some expression in tumor cells was seen in 97% of cases for HVEM, 83% for PD-L1, 79% for Gal-9 and 66% for IDO. In the discovery cohort (n = 94), we found that lack of, or low, tumor expression of PD-L1 (p < 0.001), Galectin-9 (p < 0.001) and HVEM (p < 0.001), and low CD8+TIL count (p = 0.016), were associated with poor HCC-specific survival. PD-L1, Galectin-9 and CD8+TIL count were predictive of HCC-specific survival independent of baseline clinicopathologic characteristics and the combination of these markers was a powerful predictor of HCC-specific survival (HR 0.29; p <0.001). These results were confirmed in the validation cohort (n = 60). We show that low expression levels of PD-L1 and Gal-9 in combination with low CD8+TIL count predict extremely poor HCC-specific survival and it requires a change in two of these parameters to significantly improve prognosis. In conclusion, intra-tumoral expression of these immune inhibiting molecules was observed in the majority of HCC patients. Low expression of PD-L1 and Galectin-9 and low CD8+TIL count are associated with poor HCC-specific survival. Combining immune biomarkers leads to superior predictors of HCC mortality.

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