title: Sampling modality influences the predictive value of grading in adult soft tissue extremity sarcomas.
abstract: BACKGROUND
  Histologic grade is one of the best predictors of outcome in adult soft tissue sarcomas. Current grading systems were validated on resection specimens; however, there has been a trend toward the use of biopsies to diagnosis these tumors.
  
  
  OBJECTIVE
  To determine whether the grade of an extremity soft tissue sarcoma determined on tissue obtained by either core needle biopsy or incisional biopsy is predictive of metastasis- or disease-free survival, and whether either sampling modality is superior.
  
  
  METHODS
  One hundred three core needle biopsies and 107 incisional biopsies of nonmetastatic spindle cell sarcomas of the extremities were retrieved from the archives. All cases had a minimum 2-year follow-up. Patient data and outcome and tumor characteristics were recorded. Tumors were reviewed and evaluated using the French Federation of Cancer Centers Sarcoma Group grading system. Kaplan-Meier survival curves were generated to correlate tumor grade with metastasis- and disease-free survival for both groups.
  
  
  RESULTS
  Patient and tumor characteristics were similar between groups except that more tumors were grade 3 and superficial in the incisional biopsy group. Grade determined on core needle biopsy was not predictive of either metastasis-free survival (P = .59) or disease-free survival (P = .50). In contrast, grade determined on incisional biopsy was predictive of both metastasis-free survival (P < .001) and disease-free survival (P = .001).
  
  
  CONCLUSIONS
  Biopsy, particularly core needle biopsy, represents a convenient diagnostic tool, particularly in the context of neoadjuvant therapy. However, based on these results incisional biopsy is recommended if grading is to be used to predict prognosis in spindle cell soft tissue sarcomas of the extremities.
authors.affiliation: From the Departments of Pathology and Laboratory Medicine (Drs Khoja, Dickson, Howarth, and Kandel) and Orthopaedic Surgery (Mr Griffin and Drs Wunder and Ferguson), Mount Sinai Hospital, Toronto, Ontario, Canada; and the Departments of Laboratory Medicine and Pathobiology (Drs Dickson, Howarth, and Kandel) and Surgery (Drs Wunder and Ferguson), University of Toronto, Toronto, Ontario, Canada.
authors.forename: Hatim
authors.initials: H
authors.lastname: Khoja
authors.forename: Anthony
authors.initials: A
authors.lastname: Griffin
authors.forename: Brendan
authors.initials: B
authors.lastname: Dickson
authors.forename: Jay
authors.initials: J
authors.lastname: Wunder
authors.forename: Peter
authors.initials: P
authors.lastname: Ferguson
authors.forename: David
authors.initials: D
authors.lastname: Howarth
authors.forename: Rita
authors.initials: R
authors.lastname: Kandel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods*; D062005:Biopsy, Large-Core Needle / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012509:Sarcoma / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D055815:Young Adult