ABSTRACT
OBJECTIVES: Patients with myeloma often face significant diagnostic delay, with up to one-third of UK patients diagnosed after an emergency presentation (EP). Compared with other routes, patients presenting as an emergency have more advanced disease, increased complications, and poorer prognosis. METHODS: An economic model was developed using a decision-tree framework and lifetime time horizon to estimate costs related to different presentation routes (EP, general practitioner [GP] 2-week wait, GP urgent, GP routine, and consultant to consultant) for UK patients diagnosed as having myeloma. After diagnosis, patients received one of 3 first-line management options (observation, active treatment, or end-of-life care). Inputs were derived from UK health technology assessments and targeted literature reviews, or based on authors' clinical experience where data were unavailable. Active treatment, complication, and end-of-life care costs were included. RESULTS: The average per-patient cost of treating myeloma (across all routes) was estimated at £146 261. The average per-patient cost associated with EP (£152 677) was the highest; differences were minimal compared with GP 2-week wait (£149 631) and consultant to consultant (£147 237). GP urgent (£140 025) and GP routine (£130 212) were associated with marginally lower costs. Complication (£42 252) and end-of-life care (£11 273) costs were numerically higher for EP than other routes (£25 021-£38 170 and £9772-£10 458, respectively). CONCLUSIONS: An economic benefit may be associated with earlier diagnosis, gained via reduced complication and end-of-life care costs. Strategies to expedite myeloma diagnosis and minimize EPs have the potential to improve patient outcomes and may result in long-term savings that could offset any upfront costs associated with their implementation.
Subject(s)
Multiple Myeloma , Humans , Multiple Myeloma/diagnosis , Multiple Myeloma/therapy , Delayed Diagnosis , United Kingdom , Models, EconomicABSTRACT
Heparan sulfate (HS) is a cell surface and extracellular matrix carbohydrate extensively modified by differential sulfation. HS interacts physically with canonical fibroblast growth factor (FGF) proteins that signal through the extracellular signal regulated kinase (ERK)/mitogen activated protein kinase (MAPK) pathway. At the embryonic mouse telencephalic midline, FGF/ERK signaling drives astroglial precursor somal translocation from the ventricular zone of the corticoseptal boundary (CSB) to the induseum griseum (IG), producing a focus of Slit2-expressing astroglial guidepost cells essential for interhemispheric corpus callosum (CC) axon navigation. Here, we investigated the cell and molecular function of a specific form of HS sulfation, 2-O HS sulfation catalyzed by the enzyme Hs2st, in midline astroglial development and in regulating FGF protein levels and interaction with HS. Hs2st-/- embryos of either sex exhibit a grossly enlarged IG due to precocious astroglial translocation and conditional Hs2st mutagenesis and ex vivo culture experiments show that Hs2st is not required cell autonomously by CC axons or by the IG astroglial cell lineage, but rather acts non-cell autonomously to suppress the transmission of translocation signals to astroglial precursors. Rescue of the Hs2st-/- astroglial translocation phenotype by pharmacologically inhibiting FGF signaling shows that the normal role of Hs2st is to suppress FGF-mediated astroglial translocation. We demonstrate a selective action of Hs2st on FGF protein by showing that Hs2st (but not Hs6st1) normally suppresses the levels of Fgf17 protein in the CSB region in vivo and use a biochemical assay to show that Hs2st (but not Hs6st1) facilitates a physical interaction between the Fgf17 protein and HS.SIGNIFICANCE STATEMENT We report a novel non-cell-autonomous mechanism regulating cell signaling in developing brain. Using the developing mouse telencephalic midline as an exemplar, we show that the specific sulfation modification of the cell surface and extracellular carbohydrate heparan sulfate (HS) performed by Hs2st suppresses the supply of translocation signals to astroglial precursors by a non-cell-autonomous mechanism. We further show that Hs2st modification selectively facilitates a physical interaction between Fgf17 and HS and suppresses Fgf17 protein levels in vivo, strongly suggesting that Hs2st acts selectively on Fgf17 signaling. HS interacts with many signaling proteins potentially encoding numerous selective interactions important in development and disease, so this class of mechanism may apply more broadly to other biological systems.