RESUMO
The early evaluation of prognostic tumour markers is commonly performed by comparing the survival of two groups of patients identified on the basis of a cut-off value. The corresponding hazard ratio (HR) is usually estimated, representing a measure of the relative risk between patients with marker values above and below the cut-off. A posteriori methods identifying an optimal cut-off are appropriate when the functional form of the relation between the marker distribution and patient survival is unknown, but they are prone to an overestimation bias. In the presence of a small sample size, which is typical of rare diseases, the external validation sets are hardly available and internal cross-validation could be unfeasible. We describe a new method to obtain an unbiased estimate of the HR at an optimal cut-off, exploiting the simple relation between the HR and the associated p-value estimated by a random permutation analysis. We validate the method on both simulated data and set of gene expression profiles from two large, publicly available data sets. Furthermore, a reanalysis of a previously published study, which included 134 Stage 4S neuroblastoma patients, allowed for the identification of E2F1 as a new gene with potential oncogenic activity. This finding was confirmed by an immunofluorescence analysis on an independent cohort.
RESUMO
BACKGROUND: Although a satisfactory disease control is nowadays achievable in most patients with JIA, a substantial proportion of them still do not respond adequately or reach long-term drug-free remission. According to current recommendations, treatment should be escalated in subsequent steps. A different approach is based on the assumption that the initial start of an aggressive therapy may take advantage of the "window of opportunity" and could alter the biology of the disease, leading to an improvement of long-term outcomes, including the prevention of cumulative joint damage. OBJECTIVES: This randomised clinical trial aims to compare the effectiveness of a conventional therapeutic regimen, based on treatment escalation and driven by the treat-to-target approach, with that of an early aggressive intervention based on the initial start of a combination of conventional and biological DMARDs. METHODS: JIA patients with oligoarthritis or RF negative polyarthritis aged more than 2 years and with less than 4 months of disease course will be included in the study. Children will be randomised into two arms: patients in Step-up arm with less severe oligoarthritis will undergo an intra-articular corticosteroid injection (IACI) in all affected joints; patients with polyarthritis or severe oligoarthritis will receive IACI and methotrexate. Subsequent treatment will follow a standardised protocol based on the patients' level of disease activity measured with the JADAS, according to a treat-to-target strategy. Patients in Step-down arm will receive a 6-month early combined treatment (methotrexate plus IACI for less severe oligoarthritis, methotrexate plus etanercept for severe oligoarthritis and polyarthritis). The primary endpoint is the frequency of achievement of the status of clinical remission (i.e. persistence of inactive disease for at least 6 months) at the 12-month visit. Safety events, physician-centred measures and parent/patient-reported outcomes will be collected through the Paediatric Rheumatology International Trials Organisation on line database. EXPECTED RESULTS: The STARS trial aims to provide important evidence supporting the first-line treatment choices in the care of children with oligoarticular and polyarticular JIA. If the superiority of an early aggressive therapy will be demonstrated, this will demand further studies on the biological definition of the window of opportunity for JIA. TRIAL REGISTRATION: The Trial is registered on the ClinicalTrials.gov registry (NCT03728478) on the 31st October 2018 and EU Clinical Trials Register on the 14th May 2018 (EudraCT Number: 2018-001931-27).
