Evaluation of PD-L1 expression in recurrent nonmetastatic sacral chordomas - a retrospective study

Abstract

Introduction/Objective. Chordomas are rare tumors of a notochordal origin. Wide surgical resection is recommended for treatment. However, it is associated with a high risk of morbidity and mortality. Additionally, these tumors are resistant to chemotherapy. Thus, targeted therapy is needed for the treatment of chordomas. Programmed death ligand 1 (PD-L1) is a promising target for cancer treatment. Here, we investigated PD-L1 expression in patients with chordoma in a single-center study. Methods. Formalin-fixed paraffin-embedded blocks were evaluated for immunohistochemical analysis to evaluate PD-L1 expression. Clinicopathological variables, such as sex, age, and follow-up data (recurrence and outcome), were retrospectively collected from the patients? medical records. Results. Ten patients diagnosed with sacral chordoma in a single institution between December 2015 and November 2021 were included in this study. The median patient age was 57 years and the median follow-up period was 40 months. The surgical margins were negative in all cases, without any preoperative medical treatment. Four of the ten patients showed PD-L1 positivity on immune cells. These patients showed local recurrence, without metastasis. In these cases, the median time to local recurrence was 15 months. All the patients with the disease were alive. Conclusion. This study demonstrated that PD-L1 positivity in immune cells can be used as a predictive marker for local recurrence at the time of surgical treatment. This can potentially be used to determine the necessity to administer immunotherapy.