title: Reduced expression of both Bax and Bcl-2 is independently associated with lymph node metastasis in human breast carcinomas.
abstract: Imbalance between pro-apoptotic and anti-apoptotic proteins, causing altered apoptosis, may lead to tumour development and tumour progression, and reduced response to adjuvant therapy. In this study, we evaluated the expression patterns of Bcl-2, Bcl-xL, and Bax protein in 126 primary invasive breast carcinomas, and the association with other clinicopathological parameters. We used immunohistochemical methods to evaluate protein expression. Reduced expression of both Bax and Bcl-2 was associated with lymphnode metastases in univariate analyses (one-way ANOVA) as well as in multivariate analysis (binary logistic regression) (Bcl-2 p=0.003 univariate, p=0.01 multivariate, Bax p=0.05 univariate, p=0.03 multivariate). Bcl-2 overexpression showed an inverse association with cyclin A (p=0.05), while expression of Bcl-xL showed an association only with cyclin D3 (p=0.04). Bcl-xL expression also showed a highly significant association with oestrogen receptor status (p=0.009). Bcl-2 and Bcl-xL showed an association with different D-type cyclins, indicating different pathways of pathogenesis. Expression of Bcl-2 was associated with better patient survival in univariate analysis (Kaplan meyer p=0.04), but lost its prognostic value in multivariate analysis (Cox regression p=0.2).
authors.affiliation: Department of Surgery, Akershus University Hospital, 1474 Nordbyhagen, Norway. igbukh@online.no
authors.forename: Ida R K
authors.initials: IR
authors.lastname: Bukholm
authors.forename: Geir
authors.initials: G
authors.lastname: Bukholm
authors.forename: Jahn M
authors.initials: JM
authors.lastname: Nesland
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000556:secondary; D018275:Carcinoma, Lobular / Q000378:metabolism* / Q000556:secondary; D016213:Cyclins / Q000096:biosynthesis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008137:Longitudinal Studies; D008207:Lymphatic Metastasis; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
chemical_list: C494826:BAX protein, human; C494811:BCL2L1 protein, human; D016213:Cyclins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein