ABSTRACT
Malignant brain tumors are aggressive and difficult to treat. Glioblastoma is the most common and lethal form of primary brain tumor, often found in patients with no genetic predisposition. The median life expectancy for individuals diagnosed with this condition is 6 months to 2 years and there is no known cure. New paradigms in cancer biology implicate a small subset of tumor cells in initiating and sustaining these incurable brain tumors. Here, we discuss the heterogenous nature of glioblastoma and theories behind its capacity for therapy resistance and recurrence. Within the cancer landscape, cancer stem cells are thought to be both tumor initiators and major contributors to tumor heterogeneity and therapy evasion and such cells have been identified in glioblastoma. At the cellular level, disruptions in the delicate balance between differentiation and self-renewal spur transformation and support tumor growth. While rapidly dividing cells are more sensitive to elimination by traditional treatments, glioblastoma stem cells evade these measures through slow division and reversible exit from the cell cycle. At the molecular level, glioblastoma tumor cells exploit several signaling pathways to evade conventional therapies through improved DNA repair mechanisms and a flexible state of senescence. We examine these common evasion techniques while discussing potential molecular approaches to better target these deadly tumors. Equally important, the presented information encourages the idea of augmenting conventional treatments with novel glioblastoma stem cell-directed therapies, as eliminating these harmful progenitors holds great potential to modulate tumor recurrence.
ABSTRACT
CONTEXT: Children with cancer and their families have complex needs related to symptoms, decision-making, care planning, and psychosocial impact extending across the illness trajectory, which for some includes end of life. Whether specialty pediatric palliative care (SPPC) is associated with improved outcomes for children with cancer and their families is unknown. OBJECTIVE: We conducted a systematic review following PRISMA guidelines to investigate outcomes associated with SPPC in pediatric oncology with a focus on intervention delivery, collaboration, and alignment with National Quality Forum domains. METHODS: We searched PubMed, Embase, Scopus, Web of Science, and CINAHL databases from inception until April 2020 and reviewed references manually. Eligible articles were published in English, involved pediatric patients aged 0-18 years with cancer, and contained original data regarding patient and family illness and end-of-life experiences, including symptom management, communication, decision-making, quality of life, satisfaction, and healthcare utilization. RESULTS: We screened 6682 article abstracts and 82 full-text articles; 32 studies met inclusion criteria, representing 15,635 unique children with cancer and 342 parents. Generally, children with cancer who received SPPC had improved symptom burden, pain control, and quality of life with decreased intensive procedures, increased completion of advance care planning and resuscitation status documentation, and fewer end-of-life intensive care stays with higher likelihood of dying at home. Family impact included satisfaction with SPPC and perception of improved communication. CONCLUSION: SPPC may improve illness experiences for children with cancer and their families. Multisite studies utilizing comparative effectiveness approaches and validated metrics may support further advancement of the field.
