title: AMACR is associated with advanced pathologic risk factors in sporadic colorectal adenomas.
abstract: OBJECTIVE
  To analyze alpha-methylacyl CoA racemase (AMACR) expression in relation to various dysplasia phenotypes and clinicopathological parameters of sporadic colorectal adenomas.
  
  
  METHODS
  Fifty-five cases of sporadic colorectal adenomas were categorized according to the Vienna classification for Gastrointestinal Neoplasia. These corresponded to a total of 98 different intra-lesion microscopic fields that were further independently assigned a histological grade based on the old nomenclature (mild, moderate, severe dyplasia and carcinoma in situ). AMACR expression was evaluated by immunohistochemistry and statistical analysis was performed to investigate possible associations with various clinicopathologic parameters of adenomas i.e. gender, age, localization, grade of dysplasia, size and configuration.
  
  
  RESULTS
  Patient age ranged from 41 to 84 years (mean 65 +/- 13.2 years); 37 patients were males and 18 were females. Adenomas ranged in size between 0.5 and 30 cm (mean 2 +/- 1.3 cm), including 18 tubular, 16 villous, 20 mixed or tubulovillous, and 1 giant sessile villous adenoma. AMACR expression was observed in 3 out of 16 (18.8%) of low-grade vs 23 out of 35 (62.8%) of high-grade lesions (P = 0.002). Most adenomas exhibiting high grade dysplasia with in situ carcinoma-like areas stained positive for AMACR (15/17 or 88.2%) as compared to adenomas with high grade dysplasia which contained severe dysplasia-like foci (6/15 or 40%), (P = 0.005). In AMACR positive adenomas featuring severe dysplasia-like or in situ carcinoma-like areas, AMACR staining was not necessarily observed in the in situ component. Positivity in intra-lesion of mild, moderate or severe dysplasia-like foci was more often encountered in adenomas harboring in situ, intramucosal or infiltrative carcinoma [21/33 (63.6%) vs 9/40 (22.5%), P < 0.001]. Strong AMACR expression was found in 11 out of 17 villous adenomas, but in only 1 out of 18 tubular lesions (P = 0.005). Larger lesions, i.e. > 1 cm stained more frequently for AMACR than smaller ones [27/45 (60%) vs 2/10 (20%), P = 0.02]. Overall, AMACR expression was associated with the grade of dysplasia, as well as with the size and configuration of adenomas, i.e. the consensus risk factors applied to colorectal adenoma patient surveillance.
  
  
  CONCLUSIONS
  It may be worthy to further evaluate the possible use of AMACR as an additional risk factor for the assessment of colorectal adenoma patients.
authors.affiliation: Laboratory of Pathology, Georgios Gennimatas General Hospital, Thessaloniki 54635, Greece.
authors.forename: Sotiris
authors.initials: S
authors.lastname: Lakis
authors.forename: Theodora
authors.initials: T
authors.lastname: Papamitsou
authors.forename: Constantina
authors.initials: C
authors.lastname: Panagiotopoulou
authors.forename: Rodoula
authors.initials: R
authors.lastname: Kotakidou
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Kotoula
mesh_terms: D000236:Adenoma / Q000201:enzymology* / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019998:Racemases and Epimerases / Q000378:metabolism*; D012307:Risk Factors
chemical_list: D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase