Emerging molecular-targeted therapies in early-phase clinical trials and preclinical models

Rhabdomyosarcoma: Current Therapy, Challenges, and Future Approaches to Treatment Strategies

Rhabdomyosarcoma is a rare cancer arising in skeletal muscle that typically impacts children and young adults. It is a worldwide challenge in child health as treatment outcomes for metastatic and recurrent disease still pose a major concern for both basic and clinical scientists. The treatment strategies for rhabdomyosarcoma include multi-agent chemotherapies after surgical resection with or without ionization radiotherapy. In this comprehensive review, we first provide a detailed clinical understanding of rhabdomyosarcoma including its classification and subtypes, diagnosis, and treatment strategies. Later, we focus on chemotherapy strategies for this childhood sarcoma and discuss the impact of three mechanisms that are involved in the chemotherapy response including apoptosis, macro-autophagy, and the unfolded protein response. Finally, we discuss in vivo mouse and zebrafish models and in vitro three-dimensional bioengineering models of rhabdomyosarcoma to screen future therapeutic approaches and promote muscle regeneration.

Use of Antiangiogenic Therapies in Pediatric Solid Tumors

Cancer is an important cause of death in childhood. In recent years, scientists have made an important effort to achieve greater precision and more personalized treatments against cancer. But since only a few pediatric patients have identifiable therapeutic targets, other ways to stop the neoplastic cell proliferation and dissemination are needed. Therefore, the inhibition of general processes involved in the growth and behavior of tumors can be a relevant strategy for the development of new cancer therapies. In the case of solid tumors, one of these processes is angiogenesis, essential for tumor growth and generation of metastases. This review summarizes the results obtained with the use of antiangiogenic drugs in the main pediatric malignant solid tumors and also an overview of clinical trials currently underway. It should be noted that due to the rarity and heterogeneity of the different types of pediatric cancer, most studies on antiangiogenic drugs include only a small number of patients or isolated clinical cases, so they are not conclusive and further studies are needed.

Treatment of generalized infantile myofibromatosis with sorafenib and imatinib: A case report

Infantile myofibromatosis (IM) is characterized by solitary musculoskeletal nodules presenting during infancy but can manifest as multiple lesions with visceral involvement. Multicentric IM with visceral involvement carries a high risk of mortality and there is no consensus on treatment. We present a case of a patient with multicentric IM and pulmonary involvement who progressed on several chemotherapeutic regimens and subsequently had a complete response to sorafenib and later imatinib. This report describes the novel use of sorafenib and imatinib to treat generalized IM and the role of continued tyrosine kinase inhibitor therapy to maintain remission.

Uncovering metabolism in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a myogenic tumor classified as the most frequent soft tissue sarcoma affecting children and adolescents. The histopathological classification includes 5 different histotypes, with 2 most predominant referred as to embryonal and alveolar, the latter being characterized by adverse outcome. The current molecular classification identifies 2 major subsets, those harboring the fused Pax3-Foxo1 transcription factor generating from a recurrent specific translocation (fusion-positive RMS), and those lacking this signature but harboring mutations in the RAS/PI3K/AKT signaling axis (fusion-negative RMS). Since little attention has been devoted to RMS metabolism until now, in this review we summarize the "state of art" of metabolism and discuss how some of the molecular signatures found in this cancer, as observed in other more common tumors, can predict important metabolic challenges underlying continuous cell growth, oxidative stress resistance and metastasis, which could be the subject of future targeted therapies.

Rhabdomyosarcoma of the head and neck in children

Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma in children. It is localized in the head and neck region in 40% of cases. Treatment of RMS is complex, including multi-drug chemotherapy, radiotherapy and surgery. The progress that has been accomplished in oncology in recent decades significantly improved outcomes. The 5-year survival rate raised from 25% in 1970 to 73% in 2001, according to IRS-IV data. The outcome is influenced by primary tumor localization, clinical staging, histological tumor type and age at the moment of diagnosis. The relatively rare incidence of these tumors resulted in difficulties in creating more standardized therapeutic protocols. Comparison of outcomes in large patients groups led to an increase in the number of patients with complete remission. Although survival rates of RMS patients have improved, searching for new therapeutic modalities and substances is still essential to improve outcomes in cases of more advanced stages and unfavorable tumor localizations.