title: Cytokeratin immunohistochemistry improves interobserver variability between unskilled pathologists in the evaluation of tumor budding in T1 colorectal cancer.
abstract: Tumor budding is a major risk factor for T1 colorectal cancer. Quality control of the pathological diagnosis of budding is crucial, irrespective of the pathologist's experience. This study examines the interobserver variability according to pathologists' experience and evaluates the influence of cytokeratin (CK) immunostaining in the assessment of budding. Hematoxylin-eosin (HE) and CK-immunostained slides of 40 cases with T1 primary colorectal cancer were examined. Budding grades were individually evaluated by 12 pathologists who we categorized into three groups by their experience (expert, with >10 years of experience (n = 4), senior, with 5-10 years (n = 4), and junior, < 5 years (n = 4)). The results revealed a tendency for the more experienced pathologists to assign higher budding grades compared to the less-experienced pathologists. In the junior group, the interobserver variability obtained with HE slides was poor, but it was markedly improved in the evaluation using CK-immunostained slides. The benefit of CK immunostaining was only slight in the expert group. CK immunostaining would be useful when a pathologist is not experienced enough or does not have enough confidence in the assessment of budding.
authors.affiliation: Department of Pathology, Saga University Hospital, Saga, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Kai
authors.affiliation: Department of Pathology, Saga University Hospital, Saga, Japan.|Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Aishima
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Aoki
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Takase
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Uchihashi
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Masuda
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Nishijima-Matsunobu
authors.affiliation: Department of Pathology, Saga University Hospital, Saga, Japan.|Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Mihoko
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Kousuke
authors.initials: K
authors.lastname: Ide
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakayama
authors.affiliation: Department of Pathology, Saga University Hospital, Saga, Japan.|Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Yamasaki
authors.affiliation: Departments of Pathology & Microbiology, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Toda
mesh_terms: D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism*; D008207:Lymphatic Metastasis; D060787:Neoplasm Grading; D015588:Observer Variation; D015203:Reproducibility of Results
chemical_list: D007633:Keratins
keywords: budding; colorectal cancer; cytokeratin; interobserver variability; pathological diagnosis