title: Prognostic impact of membranous ATP-binding cassette Sub-family G member 2 expression in patients with colorectal carcinoma after surgical resection.
abstract: ATP-binding cassette sub-family G member 2 (ABCG2) is a transporter protein that has been associated with multidrug resistance and poor prognosis in several types of cancers. In colorectal cancers, however, the prognostic value of ABCG2 expression is not yet clear. ABCG2 expression was analyzed by immunohistochemistry using tissue microarrays in 234 consecutive patients who underwent surgical resection. The ABCG2 expression level was defined by the composite score, determined by multiplying intensity and percentage of tumor staining scores. This was dichotomized at the median, and the association of ABCG2 expression with disease severity and patient survival was determined. ABCG2 expression in the cytoplasm and membrane was observed in 77.8% and 61.5% of the samples, respectively. High expression of ABCG2 in both the cytoplasm and membrane was found more frequently in well-differentiated lesions (P < 0.05). High expression of membranous ABCG2 was significantly associated with better overall survival (hazard ratio [HR], 0.624; 95% confidence interval [CI], 0.411-0.948; P = 0.027) and disease-specific survival (HR, 0.499; 95% CI, 0.308 - 0.808; P = 0.005) compared to low expression. However, cytoplasmic expression of ABCG2 was not significantly associated with patient survival. The expression level of membranous ABCG2 in colorectal tumors can predict post-operative patient survival, suggesting the potential for ABCG2 as a prognostic biomarker.
authors.affiliation: a Department of Internal Medicine ; College of Medicine ; The Catholic University of Korea ; Seoul , Korea.
authors.forename: Donghoon
authors.initials: D
authors.lastname: Kang
authors.affiliation: a Department of Internal Medicine ; College of Medicine ; The Catholic University of Korea ; Seoul , Korea.
authors.forename: Jae Myung
authors.initials: JM
authors.lastname: Park
authors.affiliation: b Hospital Pathology ; College of Medicine ; The Catholic University of Korea ; Seoul , Korea.
authors.forename: Chan Kwon
authors.initials: CK
authors.lastname: Jung
authors.affiliation: a Department of Internal Medicine ; College of Medicine ; The Catholic University of Korea ; Seoul , Korea.
authors.forename: Bo-In
authors.initials: BI
authors.lastname: Lee
authors.affiliation: c Surgery: College of Medicine ; The Catholic University of Korea ; Seoul , Korea.
authors.forename: Seong Taek
authors.initials: ST
authors.lastname: Oh
authors.affiliation: a Department of Internal Medicine ; College of Medicine ; The Catholic University of Korea ; Seoul , Korea.
authors.forename: Myung-Gyu
authors.initials: MG
authors.lastname: Choi
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011379:Prognosis
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins
keywords: ABCG2 protein; colorectal neoplasms; prognosis; survival