title: Routine dual-color immunostaining with a 3-antibody cocktail improves the detection of small cancers in prostate needle biopsies.
abstract: We performed dual-color immunostaining with a 3-antibody cocktail (α-methylacyl coenzyme-A racemase, CK34betaE12, and p63) on prostate biopsies from 200 patients. Current practice (hematoxylin and eosin staining followed by dual-color immunostaining on selected cases) was compared with a protocol in which routine dual-color immunostaining was provided in all cases. In the original pathology reports, adenocarcinoma was diagnosed in 87/200 (43%) patients. Small foci interpreted as putative cancers were detected with dual-color immunostaining in 14/113 patients who were originally diagnosed with a nonmalignant lesion. All of the suggested cancerous foci were independently reevaluated by 5 pathologists. A diagnosis of adenocarcinoma was assessed by consensus in 8 cases, and atypical small acinar proliferation was diagnosed in 1 case. Consensus was not reached in 5 cases. Six of the foci reclassified as cancer were of Gleason score 3 + 3 = 6, while 2 were graded as Gleason score 4 + 4 = 8. The feasibility of routine dual-color immunostaining was also tested by analyzing the time spent on microscopic assessment. Because small, atypical lesions expressing α-methylacyl coenzyme-A racemase (blue chromogen) were easy to detect using dual-color immunostaining, the microscopic analysis of dual-color immunostaining and hematoxylin-eosin staining was faster than that of hematoxylin-eosin staining alone that was later followed by dual-color immunostaining in selected cases (median 251 seconds versus 299 seconds, P < .0001). We concluded that routine dual-color immunostaining of all prostate biopsies would produce better diagnostic sensitivity with a smaller microscopy workload for the pathologist. However, minute foci interpreted as cancer with dual-color immunostaining need to be confirmed with hematoxylin-eosin staining, and minimal criteria for a definitive diagnosis of cancer are still lacking.
authors.affiliation: Institute of Medical Technology, University of Tampere and Tampere University Hospital, Tampere, Finland.
authors.forename: Teemu T
authors.initials: TT
authors.lastname: Tolonen
authors.forename: Paula M
authors.initials: PM
authors.lastname: Kujala
authors.forename: Marita
authors.initials: M
authors.lastname: Laurila
authors.forename: Mika
authors.initials: M
authors.lastname: Tirkkonen
authors.forename: Joanna
authors.initials: J
authors.lastname: Ilvesaro
authors.forename: Vilppu J
authors.initials: VJ
authors.lastname: Tuominen
authors.forename: Teuvo L J
authors.initials: TL
authors.lastname: Tammela
authors.forename: Jorma
authors.initials: J
authors.lastname: Isola
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology; D001707:Biopsy, Needle; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D007633:Keratins / Q000276:immunology; D008297:Male; D008565:Membrane Proteins / Q000276:immunology; D011467:Prostate / Q000737:chemistry; D011471:Prostatic Neoplasms / Q000276:immunology / Q000473:pathology*; D019998:Racemases and Epimerases / Q000276:immunology; D013194:Staining and Labeling / Q000379:methods*
chemical_list: C121278:CK-34 beta E12; C081876:CKAP4 protein, human; D008565:Membrane Proteins; D007633:Keratins; D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase