Systemic Therapy in Advanced Pleomorphic Liposarcoma: a Comprehensive Review

OPINION STATEMENT

The therapeutic approach of pleomorphic liposarcoma (PLPS), a rare high-grade subgroup of soft tissue sarcoma, is commonly extrapolated from the management of other LPS subtypes. Only published retrospective data on PLPS currently serve as a guide for oncologists without clear recommendations or specific guidelines. In the advanced setting, specific systemic therapy such as eribulin and trabectedin showed promising activity in comparison to conventional therapy (doxorubicin- and gemcitabine-based protocols), which currently remains the current standard of care at initial stages of the disease. The better understanding of soft tissue sarcoma (STS) pathophysiology and disease course has led to the development of adapted clinical trial designs for rare STS histotypes with specific treatment approach.

Case Report: Complete Response to Antiangiogenesis and Immune Checkpoint Blockade in an Unresectable MMR-Deficient Leiomyosarcoma Harboring Biallelic Loss of PTEN

BACKGROUND

Leiomyosarcoma (LMS) is a malignant smooth muscle neoplasm, in which the efficacy of immune checkpoint blockade (ICB) is very limited. What is worse, loss of PTEN, known as a negative factor for ICB, frequently occurred in LMS. Seeking new strategies for LMS patients harboring loss of PTEN is important and challenging.

CASE PRESENTATION

A 42-year-old Chinese male was diagnosed as having unresectable LMS of the iliopsoas. After the failure of two prior chemotherapy regimens, whole-exome sequencing revealed that tumor tissue had high tumor mutation burden (689 Muts), high microsatellite instability, and some somatic mutations, including PTEN (copy number loss and p.N323fs), MSH6 (p.F1088fs), TP53 p.R273C, ASXL1 p.G645fs, ATR p.S1843P, and CDKN2A p.A118P. Then, antiangiogenic agent (pazopanib or anlotinib) plus pembrolizumab was administered from January 2 to August 6, 2018. However, pazopanib was stopped on June 18 due to the grade 2/3 adverse effect of hand-foot skin reaction, and anlotinib was administered. Considering that the tumor shrunk after immunotherapy, he underwent radical resection on September 6, 2018. The final pathological diagnosis confirmed pathologic complete response (CR). Until the latest follow-up (September 15, 2021), no progressive disease was observed and total disease-free survival has exceeded 36 months.

CONCLUSION

We presented a patient with an unresectable mismatch repair (MMR)-deficient LMS harboring biallelic loss of PTEN who achieved CR from a combination strategy of antiangiogenesis plus pembrolizumab. Such a strategy might be a promising strategy to overcome the ICB resistance caused by the loss of PTEN. Such conclusions need to be further confirmed in further investigations.

Chemotherapy and targeted treatments of breast sarcoma by histologic subtype

Introduction: Breast sarcomas (BS) are uncommon and often present both diagnostic and therapeutic challenges. Historically, radical surgery has been the mainstay of treatment for localized breast sarcomas. On the other hand, in advanced disease, since they are a heterogeneous group of neoplasms consisting of several different subtypes including angiosarcoma, phyllodes tumor, and pleomorphic undifferentiated sarcoma, there is a lack of proven specific therapy. As a result, their treatment is based on the soft tissue sarcoma (STS) paradigm, whereas histotype-tailored approaches apply to specific subtypes like dermatofibrosarcoma protuberans. To date, advanced stages constitute an incurable form of disease and chemotherapy remains the cornerstone of treatment with the aim of palliation of symptoms and increase in survival.Areas covered: In this manuscript, we review the clinicopathologic characteristics of the most common subtypes of BS, as well as the current treatment landscape of BS, with a particular focus on opportunities and challenges provided by new targeted molecules and immunotherapy.Expert opinion: The treatment approach of advanced BS is based on the pathologic subtype. A true breakthrough has still to be obtained, as the development of new agents in BS suffers from the same weaknesses as in other STS.

Neuroendocrine neoplasia of the gastrointestinal tract revisited: towards precision medicine

Over the past 5 years, a number of notable research advances have been made in the field of neuroendocrine cancer, specifically with regard to neuroendocrine cancer of the gastrointestinal tract. The aim of this Review is to provide an update on current knowledge that has proven effective for the clinical management of patients with these tumours. For example, for the first time in the tubular gastrointestinal tract, well-differentiated high-grade (grade 3) tumours and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are defined in the WHO classification. This novel classification enables efficient identification of the most aggressive well-differentiated neuroendocrine tumours and helps in defining the degree of aggressiveness of MiNENs. The Review also discusses updates to epidemiology, cell biology (including vesicle-specific components) and the as-yet-unresolved complex genetic background that varies according to site and differentiation status. The Review summarizes novel diagnostic instruments, including molecules associated with the secretory machinery, novel radiological approaches (including pattern recognition techniques), novel PET tracers and liquid biopsy combined with DNA or RNA assays. Surgery remains the treatment mainstay; however, peptide receptor radionuclide therapy with novel radioligands and new emerging medical therapies (including vaccination and immunotherapy) are evolving and being tested in clinical trials, which are summarized and critically reviewed here.

Making progress in a rare disease: emerging therapeutics in soft tissue sarcomas

Sarcomas are rare tumors derived from mesenchymal connective tissues in the body. Because there are well over 50 histologic sarcoma subtypes, including malignant and non-malignant pathologies, clinical courses and therapeutic management are widely divergent. In general, therapeutic options across all soft tissue sarcomas are limited in number and are often generalized across multiple sarcoma histologies. The recent emergence of molecularly targeted therapies and immune-based agents presents a future of refined systemic treatment practices that are rationally tailored to the tumor by histologic subtype and biologic mechanisms.