title: NF-1Score: a prediction score for internal neurofibromas in neurofibromatosis-1.
abstract: NF-1 is associated with a 15-year decrease in life expectancy. Internal neurofibromas are associated with increased morbidity and mortality through malignant transformation and compression of neighboring organs. Our purpose was to develop and to validate a clinical score for predicting internal neurofibromas in adults. The development sample comprised 208 patients and the validation sample 191 patients. The score was developed using logistic regression. Discrimination and calibration of the model were evaluated. Four variables were independently associated with internal neurofibromas: at least two subcutaneous neurofibromas (odds ratio (OR)=4.7, [2.1-10.5]), age < or =30 years (OR=3.1, [1.4-6.8]), absence of cutaneous neurofibromas (OR=2.6, [0.9-7.5]), and fewer than six café-au-lait spots (OR=2.0 [0.9-4.6]). The score computed by linear combination of the rounded coefficients of these four variables ranged from 0 to 40 (mean, 12.8+/-10.8). The probability of internal neurofibromas was computed as exp (-2.93+0.11Score)/exp (1+(-2.93+0.11Score)). Probabilities agreed well with the observed frequencies indicating good calibration, and discrimination was adequate (AUC-ROC, 0.75) in both data sets. The presence of internal neurofibromas can be accurately predicted using a simple clinical score. Further work will establish the score threshold that identifies patients at high risk for complications.
authors.affiliation: Universite Paris 12, LIC EA4393 (Laboratoire d'Investigation Clinique), Créteil, France. sylvie.bastuji-garin@hmn.aphp.fr
authors.forename: Emilie
authors.initials: E
authors.lastname: Sbidian
authors.forename: Pierre
authors.initials: P
authors.lastname: Wolkenstein
authors.forename: Laurence
authors.initials: L
authors.lastname: Valeyrie-Allanore
authors.forename: Diana
authors.initials: D
authors.lastname: Rodriguez
authors.forename: Smail
authors.initials: S
authors.lastname: Hadj-Rabia
authors.forename: Salah
authors.initials: S
authors.lastname: Ferkal
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lacour
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Leonard
authors.forename: Luc
authors.initials: L
authors.lastname: Taillandier
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Sportich
authors.forename: Philippe
authors.initials: P
authors.lastname: Berbis
authors.forename: Sylvie
authors.initials: S
authors.lastname: Bastuji-Garin
mesh_terms: D000328:Adult; D000368:Aged; D019080:Cafe-au-Lait Spots / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009456:Neurofibromatosis 1 / Q000401:mortality* / Q000473:pathology*; D010808:Physical Examination / Q000592:standards*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D040521:Subcutaneous Tissue / Q000473:pathology; D055815:Young Adult