title: Need for objective and reproducible criteria in histopathological assessment of total mesorectal excision specimens: lessons from a national improvement project.
abstract: OBJECTIVE
  Data on quality control of the pathologic evaluation of total mesorectal excision (TME) specimens are scarce. We aimed to assess differences between evaluation by local pathologists participating in PROject on CAncer of the REctum (PROCARE; a Belgian improvement project on rectal cancer) and by a review panel of experts.
  
  
  METHODS
  Based on photographic material and histopathology slides, a Review Committee of gastrointestinal expert pathologists re-evaluated the mesorectal plane, the tumour differentiation grade, the (y)pT stage and the tumour regression grade in 444 patients previously routinely assessed by local pathologists.
  
  
  RESULTS
  The surgical plane was reported in 89% of patients and the circumferential resection margin in 88% of patients by the local pathologist. The median number of lymph nodes harvested in patients undergoing neoadjuvant radiochemotherapy was 11 and 14 in the other patients. The Review Committee downgraded the surgical plane from (intra)mesorectal to intramuscular in 17% of patients, and upgraded it from intramuscular to (intra)mesorectal in 27%. Tumour differentiation grade, T stage and tumour regression grade differed between local pathologists and the Review Committee in 15%, 10% and 38%, respectively, of patients. T stage was upgraded, mainly from T2 to T3, in 8% of patients. Tumour regression was judged by the Review Committee to be less advanced in 15% of patients.
  
  
  CONCLUSIONS
  Acknowledging some shortcomings, this study gives a realistic view of clinical practice. There are differences in interpretation with regard to both macroscopic and microscopic analysis of TME specimens. These findings indicate a need for more objective and reproducible criteria in histopathology. Being aware of this is a first step for improvement.
authors.affiliation: Department of Pathology, Erasme University Hospital, ULB, Brussels, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Demetter
authors.forename: T
authors.initials: T
authors.lastname: Vandendael
authors.forename: C
authors.initials: C
authors.lastname: Sempoux
authors.forename: N
authors.initials: N
authors.lastname: Ectors
authors.forename: C A
authors.initials: CA
authors.lastname: Cuvelier
authors.forename: N
authors.initials: N
authors.lastname: Nagy
authors.forename: A
authors.initials: A
authors.lastname: Hoorens
authors.forename: A
authors.initials: A
authors.lastname: Jouret-Mourin
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D004210:Dissection; D006801:Humans; D008197:Lymph Node Excision; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D010336:Pathology / Q000592:standards; D011786:Quality Control; D058996:Quality Improvement; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery
keywords: Total mesorectal excision; adenocarcinoma; rectum