6th-Sec010- Interactive Multidisciplinary Case Discussions

Application of Neoadjuvant Chemotherapy Based on Histological Subtype in Bone and Soft Tissue Tumors
Speaker: Dr. Eisuke KOBAYASHI, National Cancer Center, Tokyo, Japan

Abstract:
In recent years, the molecular genetic mechanisms of bone and soft tissue tumors have been gradually revealed. As a result, opportunities have arisen for chemotherapies that are tailored to the genetic abnormalities and mutations of each histologic subtype of sarcoma. These chemotherapies are expected to serve not only as chemotherapy for advanced cases but also as neoadjuvant chemotherapy to facilitate surgery. In this lecture, I will present cases with an intermediate malignant or malignant bone and soft tissue tumor who were successfully treated with histology-tailored neoadjuvant chemotherapy and surgery, based on molecular biological findings.

Novel systemic therapeutic strategies for (even) rarer sarcomas
Speaker : Dr. Tom Wei-wu CHEN, National Taiwan University Hospital, Taiwan

Abstract:
Systemic cytotoxic agents remain the cornerstone of soft tissue sarcoma(STS) tr eatment. However, the advent of molecularly guided therapies marks a new era in STS management. Dermatofibrosarcoma protuberans, characterized by the pathognomonic COL1A1::PDGFB fusion gene, responds well to imatinib, which inhibits the PDGF-PDGFR signaling axis. Inflammatory myofibroblastic tumors exhibit distinct gene fusions with ALK, ROS1, and NTRK, and their respective targeted therapies demonstrated successful outcomes. Epithelioid sarcoma, defined by the loss of INI-1/SMARCB1 protein, shows sensitivity to the EZH2 inhibitor tazemetostat in advanced stage patients. Additionally, the aberrant activation of the mammalian target of rapamycin (mTOR) pathway in perivascular epithelioid cell tumors (PEComa) has been addressed through mTOR inhibitors like sirolimus and everolimus. The AMPECT study further substantiates the efficacy of nab-sirolimus, a nanoparticle, albumin-bound, intravenously administered sirolimus, providing excellent outcomes for malignant PEComa patients. This lecture will delve into these molecularly targeted approaches, highlighting their clinical implications and integration into contemporary STS treatment paradigms

The Future of Radiotherapy in Soft-tissue Sarcomas: Dose Modulation, Hypofractionation, Flash Protons and More
Speaker: Prof. Rick HAAS, The Netherlands Cancer Institute, Amsterdam, The Netherlands

Abstract: 
Although the role of radiotherapy (RT) for soft tissue sarcomas (STS) is well established in both ESMO and NCCN clinical practice guidelines, for any patient, they leave much room for more personalized considerations . As a rule, 1.8-2 Gy fractions are advised, preferably in the preoperative setting, to an equivalent dose of 50 Gy in 5 weeks.

In this presentation, a dose reduction for myxoid liposarcomas, first clinical experiences with hypofractionation, the consequences of refraining from any radiotherapy and the value of radiosensitizers are discussed.