title: Proposal for a new T-stage classification system for distal cholangiocarcinoma: a 10-institution study from the U.S. Extrahepatic Biliary Malignancy Consortium.
abstract: Seventh AJCC distal cholangiocarcinoma T-stage classification inadequately separates patients by survival. This retrospective study aimed to define a novel T-stage system to better stratify patients after resection.
  
  
  
  Curative-intent pancreaticoduodenectomies for distal cholangiocarcinoma (1/2000-5/2015) at 10 US institutions were included. Relationships between tumor characteristics and overall survival (OS) were assessed and incorporated into a novel T-stage classification.
  
  
  
  176 patients (median follow-up: 24mo) were included. Current AJCC T-stage was not associated with OS (T1: 23mo, T2: 20mo, T3: 25mo, T4: 12mo; p = 0.355). Tumor size ≥3 cm and presence of lymphovascular invasion (LVI) were associated with decreased OS on univariate and multivariable analyses. Patients were stratified into 3 groups [T1: size <3 cm and (-)LVI (n = 69; 39.2%); T2: size ≥3 cm and (-)LVI or size <3 cm and (+)LVI (n = 82; 46.6%); and T3: size ≥3 cm and (+)LVI (n = 25; 14.2%)]. Each progressive proposed T-stage was associated with decreased median OS (T1: 35mo; T2: 20mo; T3: 8mo; p = 0.002).
  
  
  
  Current AJCC distal cholangiocarcinoma T-stage does not adequately stratify patients by survival. This proposed T-stage classification, based on tumor size and LVI, better differentiates patient outcomes after resection and could be considered for incorporation into the next AJCC distal cholangiocarcinoma staging system.
authors: Division of Surgical Oncology, Department of Surgery, Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors: Lauren M
authors: LM
authors: Postlewait
authors: Division of Surgical Oncology, Department of Surgery, Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors: Cecilia G
authors: CG
authors: Ethun
authors: Division of Surgical Oncology, Department of Surgery, Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors: Nina
authors: N
authors: Le
authors: Division of Surgical Oncology, Department of Surgery, The Johns Hopkins Hospital, Baltimore, MD, USA.
authors: Timothy M
authors: TM
authors: Pawlik
authors: Division of Surgical Oncology, Department of Surgery, The Johns Hopkins Hospital, Baltimore, MD, USA.
authors: Stefan
authors: S
authors: Buettner
authors: Department of Surgery, Stanford University Medical Center, Stanford, CA, USA.
authors: George
authors: G
authors: Poultsides
authors: Department of Surgery, Stanford University Medical Center, Stanford, CA, USA.
authors: Thuy
authors: T
authors: Tran
authors: Division of Surgical Oncology, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
authors: Kamran
authors: K
authors: Idrees
authors: Division of Surgical Oncology, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
authors: Chelsea A
authors: CA
authors: Isom
authors: Department of Surgery, Washington University School of Medicine, St Louis, MO, USA.
authors: Ryan C
authors: RC
authors: Fields
authors: Department of Surgery, Washington University School of Medicine, St Louis, MO, USA.
authors: Bradley
authors: B
authors: Krasnick
authors: Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors: Sharon M
authors: SM
authors: Weber
authors: Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors: Ahmed
authors: A
authors: Salem
authors: Division of Surgical Oncology, Department of Surgery, University of Louisville, Louisville, KY, USA.
authors: Robert C G
authors: RCG
authors: Martin
authors: Division of Surgical Oncology, Department of Surgery, University of Louisville, Louisville, KY, USA.
authors: Charles
authors: C
authors: Scoggins
authors: Department of Surgery, Wake Forest University, Winston-Salem, NC, USA.
authors: Perry
authors: P
authors: Shen
authors: Department of Surgery, Wake Forest University, Winston-Salem, NC, USA.
authors: Harveshp D
authors: HD
authors: Mogal
authors: Division of Surgical Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA.
authors: Carl
authors: C
authors: Schmidt
authors: Division of Surgical Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA.
authors: Eliza
authors: E
authors: Beal
authors: Department of Surgery, New York University, New York, NY, USA.
authors: Ioannis
authors: I
authors: Hatzaras
authors: Department of Surgery, New York University, New York, NY, USA.
authors: Gerardo
authors: G
authors: Vitiello
authors: Division of Surgical Oncology, Department of Surgery, Winship Cancer Institute, Emory University, Atlanta, GA, USA.
authors: Kenneth
authors: K
authors: Cardona
authors: Division of Surgical Oncology, Department of Surgery, Winship Cancer Institute, Emory University, Atlanta, GA, USA. Electronic address: smaithe@emory.edu.
authors: Shishir K
authors: SK
authors: Maithel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000145:classification / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018281:Cholangiocarcinoma / Q000145:classification / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000379:methods*; D016577:Pancreaticoduodenectomy / Q000009:adverse effects / Q000401:mortality; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden; D014481:United States