title: Cavity Shaving Reduces Involved Margins and Reinterventions Without Increasing Costs in Breast-Conserving Surgery: A Propensity Score-Matched Study.
abstract: BACKGROUND
  Currently, reinterventions for involved margins after breast-conserving surgery remain common. The aim of this study was to assess the capability of the cavity shave margins (CSM) technique to reduce positive margin rates and reoperations compared with simple lumpectomy (SL). The impact of CSM on the various biological portraits of breast cancer and costs were also investigated.
  
  
  METHODS
  A retrospective review of 976 consecutive patients from a single center was performed; 164 patients underwent SL and 812 received CSM. All patients were treated with an oncoplastic approach. and involved margins and reoperations were compared for each group. To avoid selection bias, propensity score-matched analysis was performed before applying a logistic regression model. Main outcomes were reanalyzed for each biological portrait, and surgery and hospitalization costs for SL and CSM were compared.
  
  
  RESULTS
  Clear margins were found in 98.3% of patients in the CSM group versus 74.4% of patients in the SL group (p < 0.001). The reoperation rate was 18.9% in the SL group and 1.9% in the CSM group (p < 0.001). After propensity score-matched logistic regression, odds ratio (OR) for positive final margin status was 6.2 (95% confidence interval [CI] 2.85-13.46; p < 0.001) without CSM, while OR for reintervention was 5.46 (95% CI 2.21-13.46; p < 0.001). CSM significantly reduced positive margins and reexcisions for Luminal A, Luminal B, and triple-negative breast cancers (p < 0.001, p < 0.001, and p = 0.0137, respectively). SL had higher global costs compared with CSM: €193,630.6 versus €177,830 for 100 treated patients (p = 0.009).
  
  
  CONCLUSIONS
  CSM reduces reexcisions, mainly in luminal breast cancers, without increasing costs.
authors.affiliation: Surgery Department, Breast Unit, IRCCS Maugeri Foundation Hospital, Pavia, Italy. fabio.corsi@unimi.it.|Department of Biomedical and Clinical Sciences, University of Milan, "Luigi Sacco" Hospital, Milan, Italy. fabio.corsi@unimi.it.
authors.forename: Fabio
authors.initials: F
authors.lastname: Corsi
authors.affiliation: Surgery Division, Department of Clinical Sciences, University of Milan, "Luigi Sacco" Hospital, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Sorrentino
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bonzini
authors.affiliation: Surgery Department, Breast Unit, IRCCS Maugeri Foundation Hospital, Pavia, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Bossi
authors.affiliation: Department of Biomedical and Clinical Sciences, University of Milan, "Luigi Sacco" Hospital, Milan, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Truffi
authors.affiliation: Division of Radiology, "Luigi Sacco" Hospital, Milan, Italy.
authors.forename: Rosella
authors.initials: R
authors.lastname: Amadori
authors.affiliation: Department of Pathology, Department of Clinical Sciences, University of Milan, "Luigi Sacco" Hospital, Milan, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Nebuloni
authors.affiliation: Surgery Division, Department of Clinical Sciences, University of Milan, "Luigi Sacco" Hospital, Milan, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Brillat
authors.affiliation: Department of Biomedical and Clinical Sciences, University of Milan, "Luigi Sacco" Hospital, Milan, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Mazzucchelli
mesh_terms: D001943:Breast Neoplasms / Q000191:economics / Q000473:pathology / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000191:economics / Q000473:pathology / Q000601:surgery*; D018275:Carcinoma, Lobular / Q000191:economics / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental / Q000191:economics*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018365:Neoplasm, Residual / Q000191:economics / Q000473:pathology / Q000601:surgery*; D011379:Prognosis; D057216:Propensity Score; D012086:Reoperation; D012189:Retrospective Studies; D064726:Triple Negative Breast Neoplasms / Q000191:economics / Q000473:pathology / Q000601:surgery*