Long-term disease control by trabectedin in a patient with dedifferentiated liposarcoma: A case report

Macrophage-Based Therapeutic Strategies in Hematologic Malignancies

Macrophages are types of immune cells, with ambivalent functions in tumor growth, which depend on the specific environment in which they reside. Tumor-associated macrophages (TAMs) are a diverse population of immunosuppressive myeloid cells that play significant roles in several malignancies. TAM infiltration in malignancies has been linked to a poor prognosis and limited response to treatments, including those using checkpoint inhibitors. Understanding the precise mechanisms through which macrophages contribute to tumor growth is an active area of research as targeting these cells may offer potential therapeutic approaches for cancer treatment. Numerous investigations have focused on anti-TAM-based methods that try to eliminate, rewire, or target the functional mediators released by these cells. Considering the importance of these strategies in the reversion of tumor resistance to conventional therapies and immune modulatory vaccination could be an appealing approach for the immunosuppressive targeting of myeloid cells in the tumor microenvironment (TME). The combination of reprogramming and TAM depletion is a special feature of this approach compared to other clinical strategies. Thus, the present review aims to comprehensively overview the pleiotropic activities of TAMs and their involvement in various stages of cancer development as a potent drug target, with a focus on hematologic tumors.

Clinical characteristics of sarcoma cases in which long-term disease control was achieved with trabectedin treatment: A retrospective study

Trabectedin is a therapeutic option for patients with advanced sarcoma. While a randomized trial demonstrated its prolonged progression-free survival (PFS), the reported PFS was <6 months. Some patients can achieve long-term disease control with this treatment. However, the reference information is insufficient. Herein, we retrospectively reviewed 51 sarcoma patients who received trabectedin. We analyzed the clinicopathological features, trabectedin dose, administration schedule, and clinical outcomes, including the overall response rate (ORR) and PFS. Among them, we assessed the detailed data of patients who achieved long-term disease control (PFS >1 year). The ORR in the 49 evaluable patients was 8%, and the median PFS in 51 patients was 7.5 months. Six patients (12%) achieved PFS of >1 year. Five of the six patients had metastatic lesions at trabectedin initiation. The pathological subtypes were myxoid liposarcoma (n = 2), leiomyosarcoma (n = 2), synovial sarcoma (n = 1), and Ewing sarcoma (n = 1). The final administration dose was the minimum dose (0.8 mg/m2) in two patients who continued the treatment over 20 cycles. The best radiological response was partial response (PR) in two myxoid liposarcoma patients and stable disease in four. The durations from trabectedin initiation to the first response in the two PR cases were 163 and 176 days, respectively. Our results support the validity of continuing trabectedin at a sustainable dose and interval in patients who can tolerate it. These results may be useful when considering the clinical application of trabectedin.

A Prolonged Response and Characteristics of Trabectedin Treatment of Metastatic Soft Tissue Sarcoma

Unique features and treatment effects of trabectedin are presented in consideration of soft tissue sarcoma management. A prolonged time on trabectedin through 59 cycles is shown. This is one of the longer reported uses of trabectedin successfully to control disease. Adjunctive cytoreduction options with surgery, radiation or ablation are presented. Future studies would be helpful to investigate treatment holidays, the impact of multi-modality care and assessment of genetics of clonal metastases. This may assist in guiding and selecting patients for priority treatment with trabectedin.

The Role of Macrophages in Cancer Development and Therapy

Macrophages are critical mediators of tissue homeostasis and influence various aspects of immunity. Tumor-associated macrophages are one of the main cellular components of the tumor microenvironment. Depending on their activation status, macrophages can exert a dual influence on tumorigenesis by either antagonizing the cytotoxic activity of immune cells or, less frequently, by enhancing antitumor responses. In most situations, TAMs suppress T cell recruitment and function or regulate other aspects of tumor immunity. The importance of TAMs targeting in cancer therapy is derived from the strong association between the high infiltration of TAMs in the tumor tissue with poor patient prognosis. Several macrophage-targeting approaches in anticancer therapy are developed, including TAM depletion, inhibition of new TAM differentiation, or re-education of TAM activation for cancer cell phagocytosis. In this review, we will describe the role of TAMs in tumor development, including such aspects as protumorigenic inflammation, immune suppression, neoangiogenesis, and enhancement of tissue invasion and distant metastasis. Furthermore, we will discuss therapeutic approaches that aim to deplete TAMs or, on the contrary, re-educate TAMs for cancer cell phagocytosis and antitumor immunity.