title: Crossover effects of estrogen receptor status on breast cancer-specific hazard rates by age and race.
abstract: BACKGROUND
  Previous studies found that the risk of breast cancer-related death is greater in estrogen receptor (ER)-negative disease than in ER-positive disease within 5 years of diagnosis, but greater for ER-positive disease than for ER-negative disease more than 5 years after diagnosis. This phenomenon is referred to as ER-positive and -negative crossover. Our aim was to evaluate this crossover by determining the timing of the hazard of breast cancer death by patient, clinical, and tumor factors.
  
  
  METHODS
  Patients with breast cancer diagnosed between 1990 and 2005 were identified from the Surveillance, Epidemiology, and End Results database. The cohort was evaluated by age at diagnosis, race, tumor ER status, tumor and nodal stage, and tumor grade. Disease-specific (DS) hazard rates were calculated.
  
  
  RESULTS
  Of the 439,444 patients identified, 77.5% had ER-positive disease. Overall, ER-negative to ER-positive DS hazard rates crossed between the years 7 and 8 after diagnosis. Earlier crossover was linked to black or Hispanic race, young age (<40 years), or tumors that were larger, higher grade, or affected the nodes. Young black (<40 years) patients who had a T3/T4 tumor with positive nodes, grade III or undifferentiated, had the earliest crossover, in year 4.
  
  
  CONCLUSIONS
  The timing of crossover of death hazard for ER-positive and ER-negative disease varies by clinical and tumor factors. These findings may help guide recommendations regarding the duration of endocrine therapy for patients with ER-positive cancer.
authors.affiliation: Department of Surgical Oncology, The First Affiliated Hospital of Xian Jiaotong University, School of Medicine, Xian, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: Dalliah M
authors.initials: DM
authors.lastname: Black
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Mittendorf
authors.affiliation: Department of Translational Medicine, The First Affiliated Hospital of Xian Jiaotong University, School of Medicine, Xian, China.
authors.forename: Peijun
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Translational Medicine, The First Affiliated Hospital of Xian Jiaotong University, School of Medicine, Xian, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.affiliation: Division of Epidemiology Human Genetics, and Environmental Sciences, The University of Texas School of Public Health, Houston, Texas, United States of America.
authors.forename: Xianglin L
authors.initials: XL
authors.lastname: Du
authors.affiliation: Department of Surgical Oncology, The First Affiliated Hospital of Xian Jiaotong University, School of Medicine, Xian, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Medical Oncology, The First Affiliated Hospital of Xian Jiaotong University, School of Medicine, Xian, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Hunt
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America; Department of Translational Medicine, The First Affiliated Hospital of Xian Jiaotong University, School of Medicine, Xian, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yi
mesh_terms: D000328:Adult; D001741:Black or African American; D000367:Age Factors; D001213:Asian; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000208:ethnology; D018592:Cross-Over Studies; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism
chemical_list: D011960:Receptors, Estrogen; D011980:Receptors, Progesterone