title: Breast cancer incidence in black and white women stratified by estrogen and progesterone receptor statuses.
abstract: BACKGROUND
  There is increasing evidence that breast cancer is a heterogeneous disease presented by different phenotypes and that white women have a higher breast cancer incidence rate, whereas black women have a higher mortality rate. It is also well known that white women have lower incidence rates than black women until approximately age 40, when rate curves cross over and white women have higher rates. The goal of this study was to validate the risk of white and black women to breast cancer phenotypes, stratified by statuses of the estrogen (ER) and progesterone (PR) receptors.
  
  
  RESULTS
  SEER17 data were fractioned by receptor status into [ER+, PR+], [ER-, PR-], [ER+, PR-], and [ER-, PR+] phenotypes. It was shown that in black women compared to white women, cumulative age-specific incidence rates are: (i) smaller for the [ER+, PR+] phenotype; (ii) larger for the [ER-, PR-] and [ER-, PR+] phenotypes; and (iii) almost equal for the [ER+, PR-] phenotype. Clemmesen's Hook, an undulation unique to women's breast cancer age-specific incidence rate curves, is shown here to exist in both races only for the [ER+, PR+] phenotype. It was also shown that for all phenotypes, rate curves have additional undulations and that age-specific incidence rates are nearly proportional in all age intervals.
  
  
  CONCLUSIONS
  For black and white women, risk for the [ER+, PR+], [ER-, PR-] and [ER-, PR+] phenotypes are race dependent, while risk for the [ER+, PR-] phenotype is almost independent of race. The processes of carcinogenesis in aging, leading to the development of each of the considered breast cancer phenotypes, are similar in these racial groups. Undulations exhibited on the curves of age-specific incidence rates of the considered breast cancer phenotypes point to the presence of several subtypes (to be determined) of each of these phenotypes.
authors.affiliation: Eppley Cancer Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA.
authors.forename: Michael X
authors.initials: MX
authors.lastname: Gleason
authors.forename: Tengiz
authors.initials: T
authors.lastname: Mdzinarishvili
authors.forename: Simon
authors.initials: S
authors.lastname: Sherman
mesh_terms: D000367:Age Factors; D044383:Black People; D001943:Breast Neoplasms / Q000145:classification / Q000208:ethnology* / Q000401:mortality; D005260:Female; D006801:Humans; D015994:Incidence; D010641:Phenotype; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012307:Risk Factors; D018426:SEER Program / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology; D044465:White People; D001741:Black or African American
chemical_list: D011960:Receptors, Estrogen; D011980:Receptors, Progesterone