Background To investigate the clinical efficacy and potential mechanisms of immune checkpoint inhibitors (PD-1 inhibitors) combined with chemotherapy and targeted therapy in ovarian cancer patients with brain metastases, and to analyze the relationship between the number of brain metastases, tumor microenvironment characteristics, and prognosis. Materials and methods A retrospective analysis was conducted on the clinical data of two ovarian cancer patients with brain metastases. One patient had a single brain metastasis and received comprehensive treatment including surgery, radiotherapy, chemotherapy, PD-1 inhibitor (tislelizumab), and PARP inhibitor (niraparib). The other patient had multiple brain metastases and was treated with chemotherapy combined with PD-1 inhibitor. Tissue microarray immunohistochemistry was used to detect the expression of immune markers (CD4, CD8, CD31, PD-L1, etc.) in primary tumors and brain metastases. Gene testing was performed to evaluate homologous recombination repair deficiency (HRD) status. Results The patient with a single brain metastasis achieved complete response (CR) after comprehensive treatment, with significantly prolonged progression-free survival. The patient with multiple brain metastases showed significant short-term efficacy but died due to complications. Immunohistochemistry revealed higher expression of CD4, CD8, CD31, and PD-L1 in brain metastases compared to the primary tumor, suggesting increased T-cell infiltration and enhanced immune activity in the tumor microenvironment. Gene testing confirmed HRD positivity in the first patient, and maintenance therapy with PARP inhibitor combined with PD-1 inhibitor was effective. Conclusion PD-1 inhibitors combined with chemotherapy and targeted therapy may provide a new treatment option for ovarian cancer patients with brain metastases, particularly those with single brain metastases who can achieve long-term survival through comprehensive treatment. The immune microenvironment characteristics of brain metastases (e.g., high PD-L1 expression, T-cell infiltration) may predict the efficacy of immunotherapy, but the prognosis for patients with multiple brain metastases remains poor. Further research is needed to explore the correlation between peripheral blood immune markers and treatment response in brain metastases.
Li et al. (Thu,) studied this question.