title: The R.E.N.A.L. nephrometric nomogram cannot accurately predict malignancy or aggressiveness of small renal masses amenable to partial nephrectomy.
abstract: BACKGROUND
  The prediction of histology of SRM could be essential for their management. The RNN is a statistical tool designed to predict malignancy or high grading of enhancing renal masses. In this study we aimed to perform an external validation of the RNN in a cohort of patients who received a PN for SRM.
  
  
  METHODS
  This was a multicentric study in which the data of 506 consecutive patients who received a PN for cT1a SRM between January 2010 and January 2013 were analyzed. For each patient, the probabilities of malignancy and aggressiveness were estimated preoperatively using the RNN. The performance of the RNN was evaluated according to receiver operating characteristic (ROC) curve, calibration plot, and decision curve analyses.
  
  
  RESULTS
  The area under the ROC curve for malignancy was 0.57 (95% confidence interval [CI], 0.51-0.63; P = .031). The calibration plot showed that the predicted probability of malignancy had a bad concordance with observed frequency (Brier score = 0.17; 95% CI, 0.15-0.19). Decision curve analysis confirmed a poor clinical benefit from use of the system. The estimated area under the ROC curve for high-grade prediction was 0.57 (95% CI, 0.49-0.66; P = .064). The calibration plot evidenced a bad concordance (Brier score = 0.15; 95% CI, 0.13-0.17). Decision curve analysis showed the lack of a remarkable clinical usefulness of the RNN when predicting aggressiveness.
  
  
  CONCLUSIONS
  The RNN cannot accurately predict histology in the setting of cT1a SRM amenable to PN.
authors.affiliation: Spedali Civili Hospital, University of Brescia, Brescia, Italy. Electronic address: alessandro_antonelli@me.com.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Antonelli
authors.affiliation: Spedali Civili Hospital, University of Brescia, Brescia, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Furlan
authors.affiliation: Data Methods and Systems Statistical Laboratory, University of Brescia, Brescia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Sandri
authors.affiliation: Careggi Hospital, University of Florence, Florence, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Minervini
authors.affiliation: S. Pio da Pietrelcina Hospital, Vasto, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Cindolo
authors.affiliation: Carlo Poma Hospital, Mantova, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Parma
authors.affiliation: Hospital "Maggiore della Carità," Eastern Pedmont University, Novara, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zaramella
authors.affiliation: Abano Policlinic Hospital - Abano Terme, Padua, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Porreca
authors.affiliation: Careggi Hospital, University of Florence, Florence, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Vittori
authors.affiliation: Carlo Poma Hospital, Mantova, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Samuelli
authors.affiliation: Abano Policlinic Hospital - Abano Terme, Padua, Italy.
authors.forename: Donato
authors.initials: D
authors.lastname: Dente
authors.affiliation: S. Pio da Pietrelcina Hospital, Vasto, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Berardinelli
authors.affiliation: Careggi Hospital, University of Florence, Florence, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Raspollini
authors.affiliation: Careggi Hospital, University of Florence, Florence, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Serni
authors.affiliation: Careggi Hospital, University of Florence, Florence, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Carini
authors.affiliation: Hospital "Maggiore della Carità," Eastern Pedmont University, Novara, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Terrone
authors.affiliation: S. Pio da Pietrelcina Hospital, Vasto, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Schips
authors.affiliation: Spedali Civili Hospital, University of Brescia, Brescia, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Simeone
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000601:surgery; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009392:Nephrectomy; D049451:Nomograms; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D055815:Young Adult
keywords: High-grade; Malignancy; Partial nephrectomy; RENAL nephrometry nomogram; Small renal mass