Quality of life, resource utilisation and health economics assessment in advanced neuroendocrine tumours: a systematic review

Neuroendocrine tumours (NET) are often diagnosed at an advanced stage when the prognosis is poor for patients, who often experience diminished quality of life (QoL). As new treatments for NET become available, it is important to characterise the associated outcomes, costs and QoL. A comprehensive search was performed to systematically review available data in advanced NET regarding cost of illness/resource utilisation, economic studies/health technology assessment and QoL. Four rounds of sequential review narrowed the search results to 22 relevant studies. Most focused on surgical procedures and diagnostic tools and contained limited information on the costs and consequences of medical therapies. Multiple tools are used to assess health-related QoL in NET, but few analyses have been conducted to assess the comparative impact of available treatment alternatives on QoL. Limitations include English language and the focus on advanced NET; ongoing terminology and classification changes prevented pooled statistical analyses. This systematic review suggests a lack of comparative economic and outcomes data associated with NET treatments. Further research on disease costs, resource utilisation and QoL for patients with advanced NET is warranted.

Sorafenib and bevacizumab for recurrent metastatic hepatoblastoma: stable radiographic disease with decreased AFP

We report the use of sorafenib and bevacizumab in combination for a patient with recurrent metastatic hepatoblastoma (HB). This combination demonstrated activity against our patient's refractory HB that had been extensively treated with multiple prior chemotherapeutic regimens. The patient had stabilization of radiographic disease coupled with an 83% decrease in his alpha-fetoprotein level. Given the response in this setting and the paucity of other available options, consideration could be given to using this combination as therapy in patients with recurrent HB who have failed more traditional agents.

A shining light in the darkness for the treatment of pancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors are rare neoplasms; past decades have seen limited research channeled into this area. Recently, 2 placebo-controlled phase III trials using 2 drugs--everolimus and sunitinib--with distinct molecular rationales achieved their principal objective of increasing survival in patients with advanced pancreatic neuroendocrine tumors (PNET). Nonetheless, several questions remain unanswered, notably defining the optimal schedule for integrating these targeted agents with conventional cytotoxics and other treatment options, and identifying appropriate biomarkers for patients with the potential to derive greater benefit. In this article, we analyze the results of the 2 largest studies ever completed in patients with PNETs and discuss the challenges for future drug development in this setting.

SUMMARY

Sunitinib and everolimus will become new treatment options for patients with PNETs and will be integrated into the complex therapeutic management of this disease. In this review, we summarize the evidence-based data of these drugs as well as the molecular-based science in this setting that will lay the groundwork for future studies.

Relevance of angiogenesis in neuroendocrine tumors

While traditional cytotoxic drugs have shown limited efficacy in neuroendocrine tumors (NETs), their biological features have been characterized and can be exploited therapeutically. Their most prominent trait is an extraordinary vascularization in low-grade NETs and an hypoxia-dependent angiogenesis in high-grade NETs, which is associated to a significant expression of many proangiogenic molecules. Therefore, several antiangiogenic compounds have been tested in these malignancies, and among these, sunitinib has demonstrated activity in pancreatic NET patients by dually targeting the VEGFR and PDGFR pathways. In spite of these efficacious clinical results, apparent resistance to antiangiogenic therapies has been described in NET animal models and in clinical trials. Therefore, overcoming antiangiogenic resistance is a crucial step in the subsequent development of antiangiogenic therapies. Several strategies have been postulated to fight resistance, but preclinical studies and clinical trials will investigate and address these therapeutic approaches in the coming years in order to overcome resistance to antiangiogenic therapies in NETs.

Combining antiangiogenics to overcome resistance: rationale and clinical experience

Antiangiogenic therapies are now well established in oncology clinical practice; however, despite initial optimism, the results of late-phase trials, especially in the adjuvant setting, have largely proved disappointing. In the context of metastatic disease, resistance to antiangiogenic agents arises through a range of mechanisms, including the development of alternative angiogenic pathways. One of the proposed strategies to overcome this resistance is to combine antiangiogenic agents with different mechanisms of action. Early-phase clinical trials assessing the tolerability and efficacy of different combinations of antiangiogenic drugs, including those that target the VEGF pathway or the angiopoietins, as well as vascular disrupting agents, are increasing in number. An example of this strategy is the combination of sorafenib and bevacizumab, which has elicited major responses in different tumor types, including ovarian carcinoma and glioblastoma. However, overlapping and cumulative toxicities pose a real challenge. This review summarizes the preclinical rationale for this approach and current clinical experience in combining antiangiogenic therapies.