Favorable outcome of a histiocytic sarcoma patient treated with immune checkpoint inhibitor: a case report.

Introduction and Importance: Histiocytic sarcoma (HS) is an extremely rare malignancy in which there has been no standard treatment approach. Some preclinical studies have provided rationales for the application of immunotherapy in advanced HS. Case Presentation: The authors reported a case of a 61-year-old patient with metastatic HS who had a rapid progression on ifosfamide, carboplatin, and etoposide chemotherapy. The authors performed PD-L1 testing, which showed a strong positivity in 90% of tumor cells. The patient was then treated with pembrolizumab 200 mg every 3 weeks. He refused palliative radiotherapy. A dramatic response in all sites was recorded on the PET-CT scan after three cycles. He was maintained on pembrolizumab, reaching over 30 months without disease progression. Clinical Discussion: Recent molecular data suggests there could be a role of immunotherapy in HS. In our patient, the disease was refractory to chemotherapy and pembrolizumab has been given based on the strong PD-L1 expression. Response to immunotherapy has also been recorded in several cases with malignant histiocytic neoplasm. Conclusion: Immunotherapy might bring sustained disease remission in PD-L1 high expression HS and further studies evaluating the role of immune checkpoint inhibitor in this disease are warranted.

Systemic chemotherapy combined with radiofrequency ablation for colorectal cancer with liver metastasis: a retrospective cohort study.

This study aims to evaluate the efficacy of systemic chemotherapy combined with radiofrequency ablation in the treatment of inoperable colorectal cancer with liver metastasis. Materials and methods: The authors conducted a retrospective cohort analysis on 30 patients diagnosed as colorectal cancer with liver metastasis who underwent systemic chemotherapy combined with radiofrequency ablation of the liver lesions from January 2017 to August 2020 at our institution. Responses was evaluated by International Working Group on Image-guided Tumor Ablation criteria, along with progression-free survival. Results: The response rate after 4 cycles and 8 cycles of chemotherapy were 73.3% and 85.2%, respectively. All patients achieved responses after of radiofrequency therapy, with the rates of complete response and partial response were 63.3% and 36.7%. The median progression-free survival was 16.7 months. After radiotherapy ablation, all patients had mild to moderate hepatic pain, 10% of patients had fever and increased liver enzymes occurred in 90% of patients. Conclusions: Systemic chemotherapy combined with radiofrequency ablation was safe and effective in colorectal cancer with liver metastasis and warrants further large-scale studies.