title: Tumor budding in colorectal carcinoma assessed by cytokeratin immunostaining and budding areas: possible involvement of c-Met.
abstract: Tumor budding/sprouting has been shown to be an independent adverse prognostic factor in T1 and T3N0 colorectal carcinomas, however, its assessment could be improved by more accurate identification of budding carcinoma cells and consideration of budding areas. Moreover, tumor budding mechanisms are yet to be defined. In this study, we evaluated the identification of budding tumor cells by either H&E staining alone or H&E with immunohistochemistry and developed a scoring system based on budding grades and areas. We examined whether the budding score correlated with clinicopathologic features and prognosis and the association between tumor budding/sprouting and c-Met protein expression and phosphorylation and MET gene copy numbers because c-Met is known to play an important role in colorectal carcinoma tumorigenesis. Cytokeratin immunohistochemistry could identify tumors with shorter disease-free survival (DFS) from the low-grade budding group assessed with H&E alone. High budding scores based on budding grade and area were more significantly correlated with DFS than scores obtained using the budding grade alone. In tumors with a high budding score, c-Met expression and phosphorylation levels and MET gene copy numbers were significantly increased at the invasive front compared with those in superficial tumor portions. This study showed for the first time that high levels of phospho-c-Met at the invasive front were significantly associated with a high budding score and shorter DFS. In conclusion, a budding score assessed by budding grades and budding-positive areas correlates highly with clinicopathologic aggressive features of colorectal carcinoma.
authors.affiliation: Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan; Department of Gastroenterological Surgery, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Satoh
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nimura
authors.forename: Mikiko
authors.initials: M
authors.lastname: Aoki
authors.forename: Makoto
authors.initials: M
authors.lastname: Hamasaki
authors.forename: Kaori
authors.initials: K
authors.lastname: Koga
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kataoka
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nabeshima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007633:Keratins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D010766:Phosphorylation; D011379:Prognosis; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D007633:Keratins; D019859:Proto-Oncogene Proteins c-met
keywords: c-Met; sprouting; tumor budding; tumor invasion