A retrospective analysis of immunohistochemical determined IRF4 (interferon regulating factor 4) expression in a consecutive cohort of 114 ovarian cancer patients

Background:

Tumor-infiltrating lymphocytes influence the prognosis of solid tumors, including ovarian cancer (OC). The immunoregulatory transcription factor (IRF4) is mainly expressed in plasma cells and regulates immunoglobulin class switch recombination as well as plasma cell differentiation. Therefore, we analyzed the influence IRF4 expression in a consecutive cohort of OC patients.

Methods:

IRF4 expression was evaluated by immunostaining. Differences in IRF4 expression among subgroups of established clinico-pathological features like age, histological subtype, tumor stage, histological grading, postoperative tumor burden and completeness of chemotherapy were determined by x² test. The impact of IRF4 expression on PFS and OS was examined by univariate and multivariate Cox analysis adjusted for established clinicalo-pathological factors and Kaplan-Meier survival analysis.

Results:

114 patients entered this study. IRF4 was expressed in 51.7% of the entire cohort. 72.3% patients with high-grade serous OC showed IRF4 expression compared to 37.3% patients with a non high-grade serous OC (p < 0.001). Univariate Cox-Regression analysis revealed no prognostic impact of IRF4 expression in terms of PFS (p = 0.35) and OS (p = 0.98). Kaplan-Meier plots failed to show any prognostic impact for PFS (p = 0.35) and OS (p = 0.98), too. Established clinic-pathological factors retained their prognostic power as tumor stage in terms of PFS (< 0.001) and as postoperative residual tumor burden (p = 0.04), tumor stage (< 0.001), histological grade (p = 0.02) and completeness of chemotherapy (p < 0.001) in terms of OS, respectively.

Conclusion:

Immunohistochemically determined IRF4 expression correlated with high-grade serous OC. However, it failed to show to any prognostic relevance in our cohort of 114 patients.