Upregulation of the histone -H2AX correlates with worse patient survival and basal-like subtype in pancreatic ductal adenocarcinoma

Purpose Patients with pancreatic ductal adenocarcinoma (PDAC) have yet to experience significant benefits from targeted therapy. Olaparib is currently the only active substance in BRCA-mutated PDACs that successfully influences the DNA repair of carcinoma cells. H2AX belongs to the histone family and is known as a part of the DNA repair system. The inhibition of gamma-H2AX could lead to the inhibition of mitotically active tumor cells. Therefore, we aimed to evaluate the predictive value of the gamma-H2AX in patients with PDAC. Methods All included patients (n = 311) received a pancreatic resection with curative intention in one of our PANCALYZE study centers. Subsequently, they were enrolled in a standardized follow-up protocol. Immunohistochemical stainings for gamma-H2AX were conducted on tissue microarrays. Results Patients exhibiting high levels of gamma-H2AX expression experience more frequent R1 resections, indicating advanced tumor stages in this subgroup. Additionally, patients with high gamma-H2AX expression demonstrated significantly poorer survival compared to those with low expression (median OS: 15 vs. 25 months, p < 0.001). In multivariate analyses, high gamma-H2AX expression could be identified as an independent risk factor for worse patient survival. Moreover, high gamma-H2AX expression could be more frequently observed in the more aggressive basal-like subtype. Conclusion gamma-H2AX can be characterized as a predictive biomarker for poorer patient survival. Consequently, upcoming clinical trials focused on the efficacy of targeted therapies influencing the DNA repair system and radiotherapy should evaluate gamma-H2AX as a potential biomarker for therapy response. Furthermore, gamma-H2AX may serve as a viable target for treatment in the future.