Safety of eribulin mesylate and concomitant radiotherapy for metastatic breast cancer: a single-center experience

Aim: This study evaluates, for the first time, the safety of eribulin in metastatic breast cancer patients concomitantly treated with palliative radiotherapy (RT). Patients & materials: A total of 17 patients were pretreated for metastatic breast cancer. Patients received eribulin mesylate and bone RT. Results: The most frequent grade 3 hematologic adverse events were neutropenia (56%) and anemia (20%). Mean pain score decreased from 2 (baseline) to 0.7 (end of observation). Analgesic score remained stable (1.8 vs 1.6). Bone pain scores dropped within a few weeks and remained below baseline values throughout the analysis. The overall response rate was 29%, and the clinical benefit rate was 59%. Conclusion: Eribulin is characterized by a manageable safety profile also when combined with palliative RT.

Managing Liposarcomas: Cutting Through the Fat

Liposarcomas are one of the most common of more than 50 histologic subtypes of soft tissue sarcomas that, themselves, are heterogeneous. Liposarcomas fall into four distinct histologic subtypes: atypical lipomatous tumor/well-differentiated liposarcoma, dedifferentiated liposarcoma, myxoid (round cell) liposarcoma, and pleomorphic liposarcoma. Definitive treatment remains surgical resection with negative margins for resectable disease. However, well-differentiated liposarcomas that are large or difficult to operate upon should be followed with close surveillance as long as there is no radiologic concern for a dedifferentiated component. In contrast, first-line chemotherapy with anthracycline with or without ifosfamide, or gemcitabine and docetaxel should be used for inoperable myxoid (round cell) or pleomorphic liposarcomas, which are relatively responsive to chemotherapy. In the second- and third-line setting, myxoid liposarcomas, in particular, seem to be sensitive to trabectedin, which was recently approved by the US Food and Drug Administration (FDA). Eribulin offered a survival benefit when compared with dacarbazine in the third-line setting in liposarcomas (other than the well-differentiated subtype) and is now FDA approved. Recent studies have identified distinct genetic aberrations that not only aid in the diagnosis of liposarcoma subtypes but represent actionable targets. Cyclin-dependent kinase 4 and murine double minute 2 are overexpressed in well-differentiated and dedifferentiated liposarcomas and offer opportunities that are being pursued in clinical trials. It is critical that liposarcomas are not approached by oncologists as one disease entity but rather subclassified into distinct subtypes using histologic and molecular tools before formalizing a treatment plan.

Histology-Driven Therapy

Soft tissue tumors (STTs) are rare mesenchymal neoplasms accounting for less than 1% of adult cancers. More than 50 different subtypes of STTs have been identified, with this number expected to grow as our understanding of the complex genetic landscape of these diseases improves. As the classification of soft tissue neoplasms continues to diversify, so does the approach to therapy. Accurate histopathologic diagnosis, utilizing the appropriate ancillary immunohistochemical and molecular diagnostic platforms, underpins the oncologic management of soft tissue sarcomas. As increasing numbers of reproducible genetic abnormalities in soft tissue neoplasms are defined, molecular genetic and molecular cytogenetic investigations have become a standard part of the ancillary diagnostic repertoire. However, other soft tissue neoplasms lack reproducible genetic abnormalities, and for these, traditional histology and immunohistochemistry remain the cornerstones for diagnosis. Here, we give an overview of histology-driven therapy in STTs, highlighting the critical role of accurate surgical pathology in guiding the systemic treatment of patients with these neoplasms, and the importance of close collaboration between the surgical pathologist and the oncologist. We also summarize what is considered standard practice in nonhistology- and histology-driven therapy.