title: Cyclin D1 overexpression is associated with estrogen receptor expression in Caucasian but not African-American breast cancer.
abstract: BACKGROUND
  African-American (AA) breast cancer patients consistently show a shortened survival when compared with Caucasian patients. This worse prognosis is most likely due to a combination of socioeconomic factors and differences in tumor biology. Previous studies have demonstrated that cyclin D1 overexpression is strongly associated with estrogen receptor (ER) expression in breast cancer, but these series either included primarily Caucasian patients or did not specify race. MATERIALS AND METHODS. We analyzed 200 breast cancer cases obtained from AA and Caucasian patients who were matched on age, stage, ER status, and year of diagnosis. We examined expression levels of cyclin D1, p53, p27Kip1 (p27), and p21Cip1 (p21), and correlated their expression with ER status.
  
  
  RESULTS
  Cyclin D1, p53, p27, and p21 expression rates were similar in matched cases of AA and Caucasian breast cancer (p values>0.05). However, cyclin D1 overexpression was significantly associated with ER status in only the Caucasian (p=0.0005), and not the AA cases (p=0.07).
  
  
  CONCLUSIONS
  This finding suggests a novel biological difference, which may contribute to the more aggressive phenotype of AA breast cancer.
authors.affiliation: Herbert Irving Comprehensive Cancer Center and the Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA. akj3@columbia.edu
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Joe
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Memeo
authors.forename: Judith
authors.initials: J
authors.lastname: Mckoy
authors.forename: Mahesh
authors.initials: M
authors.lastname: Mansukhani
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Alexa
authors.initials: A
authors.lastname: Avila-Bront
authors.forename: Jenny
authors.initials: J
authors.lastname: Romero
authors.forename: Huiling
authors.initials: H
authors.lastname: Li
authors.forename: Andrea
authors.initials: A
authors.lastname: Troxel
authors.forename: Hanina
authors.initials: H
authors.lastname: Hibshoosh
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People; D001943:Breast Neoplasms / Q000208:ethnology* / Q000378:metabolism* / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism; D015331:Cohort Studies; D019938:Cyclin D1 / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D044465:White People
chemical_list: D018797:Cell Cycle Proteins; D011960:Receptors, Estrogen; D019938:Cyclin D1