title: Apparent diffusion coefficient value measurements with diffusion magnetic resonance imaging correlated with the expression levels of estrogen and progesterone receptor in breast cancer: A meta-analysis.
abstract: OBJECTIVE
  Apparent diffusion coefficient (ADC) value measurement of nodes in diffusion-weighted images (DWI) has been widely used for diagnosis and differential diagnosis of human tumors. We evaluated whether the ADC provided by DWI varies according to the state of estrogen receptors (ER) and progesterone receptors (PR) in breast cancer (BC).
  
  
  METHODS
  English and Chinese electronic databases were searched for potentially relevant studies followed by a comprehensive literature search. Summary standardized mean difference (SMD) with 95% confidence interval (CI) was used for ER and PR category of ADC value with the use of the Z test.
  
  
  RESULTS
  Final analysis from 6 eligible cohort studies between 2010 and 2012 were selected for inclusion. Overall estimates revealed that the mean ADC of ER-positive or PR-positive cancer was significantly lower than that of ER-negative or PR-negative breast cancer (ER- VS. ER+: SMD = 0.64, 95% CI: 0.02-1.27, P = 0.042; PR- VS. PR+: SMD = 0.45, 95% CI: 0.04-0.86, P = 0.032). Country-stratified analysis indicated the mean ADC of ER-positive cancer was significantly lower in China (SMD = 3.92, 95% CI: 2.22-5.62, P < 0.001). Further subgroup analysis by MRI machine type implied that ADC values may be a potential diagnostic indicator for PR levels in breast cancer only when using Non-Phillips 1.5T scanner (SMD = 0.88, 95% CI: 0.64-1.12, P < 0.001).
  
  
  CONCLUSIONS
  ADC values vary significantly according to the ER and PR levels in BC patients, indicating that cancer heterogeneity affects imaging parameters. DWI could therefore be critical for clinical applications of ADC values.
authors.forename: Lin
authors.initials: L
authors.lastname: Meng
authors.affiliation: The Second Laboratory of Cancer Research Institute, The First Hospital of Medical University, Shenyang, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Ma
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology; D002681:China; D038524:Diffusion Magnetic Resonance Imaging; D004967:Estrogens / Q000235:genetics; D005260:Female; D018740:Genetic Heterogeneity; D006801:Humans; D011374:Progesterone / Q000235:genetics; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000235:genetics; D011980:Receptors, Progesterone / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D004967:Estrogens; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011374:Progesterone