title: Novel factors to improve prediction of nodal positivity in patients with clinical T1/T2 breast cancers.
abstract: BACKGROUND
  Memorial Sloan Kettering Cancer Center (MSKCC) and MD Anderson Cancer Center (MDACC) have established nomograms to predict sentinel node positivity. We propose the addition of two novel variables-distance of tumor from the nipple and from the skin-can improve their performance.
  
  
  METHODS
  Ultrasounds of clinical T1/T2 tumors were reviewed. Distances of the tumor from the skin and from the nipple were measured. MSKCC and MDACC nomogram predictions and the AUC-ROC for each model were calculated. The added utility of the two variables was then examined using multiple logistic regression.
  
  
  RESULTS
  Of 401 cancers studied, 79 (19.7 %) were node positive. The mean distance of tumors from the nipple in node-positive patients was 4.9 cm compared with 6.0 cm in node-negative patients (p = 0.0007). The mean distance of tumors from the skin was closer in node-positive cases (0.8 cm) versus node-negative cases (1.0 cm, p = 0.0007). The MSKCC and MDACC nomograms AUC-ROC values were 0.71 (95 % CI 0.64-0.77) and 0.74 (95 % CI 0.68-0.81). When adjusted for the MSKCC predicted probability, addition of both distance from nipple (p = 0.008) and distance from skin (p = 0.02) contributed significantly to prediction of nodal positivity and improved the AUC-ROC to 0.75 (95 % CI 0.70-0.81). Similarly, distance from nipple (p = 0.002), but not distance from skin (p = 0.09), added modestly to the MDACC nomogram performance (AUC 0.77; 95 % CI 0.71-0.83).
  
  
  CONCLUSIONS
  Distance of tumor from the nipple and from the skin are important variables associated with nodal positivity. Adding these to established nomograms improves prediction of nodal positivity.
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Torstenson
authors.forename: Miraj G
authors.initials: MG
authors.lastname: Shah-Khan
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Hoskin
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Morton
authors.forename: Darcy L
authors.initials: DL
authors.lastname: Adamczyk
authors.forename: Katie N
authors.initials: KN
authors.lastname: Jones
authors.forename: Jane
authors.initials: J
authors.lastname: Case
authors.forename: Stephane
authors.initials: S
authors.lastname: Chartier
authors.forename: Judy C
authors.initials: JC
authors.lastname: Boughey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000473:pathology* / Q000601:surgery; D018275:Carcinoma, Lobular / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D009558:Nipples / Q000473:pathology* / Q000601:surgery; D049451:Nomograms; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D021701:Sentinel Lymph Node Biopsy; D012867:Skin / Q000473:pathology*