title: Digit ratio (2D:4D) in Chinese women with breast cancer.
abstract: OBJECTIVE
  Digit ratio, especially second-to-fourth digit ratio (2D:4D) is established in utero and is positively correlated with oestrogen in men and women. It is a putative biomarker for prenatal hormone exposure and may represent an individual predisposition to certain diseases (e.g., breast cancer). The aim of the present study is to investigate whether there is a link between digit ratio (2D:4D) and breast cancer in Chinese populations.
  
  
  METHODS
  The controls we chose were healthy subjects-age and -sex matched to the patients diagnosed with breast cancer. Photocopies of the two hands of 218 women (controls: 109; patients: 109) were collected. Left hand, right hand, mean hand, and right minus left 2D:4D (Dr-l ) were analyzed.
  
  
  RESULTS
  The patients with breast cancer presented significantly higher 2D:4D than controls (left: P < 0.01; right: P < 0.05; mean: P < 0.05). The mean values of 2D:4D on the left hand were significantly higher than those on the right hand in the two groups, respectively (controls: P < 0.05; patients: P ≤ 0.01). In patients, there was a significantly negative correlation between 2D:4D (left hand: P < 0.01; right hand, mean: P < 0.05) and the presented age with breast cancer, but no association between Dr-l and age of presented disease.
  
  
  CONCLUSIONS
  Digit ratio (2D:4D) may correlate with the increased risk of breast cancer.
authors.affiliation: Department of Medical Genetic and Cell Biology, Ningxia Medical University, Yinchuan, 750004, China; Key Laboratory of Reproduction and Genetics in Ningxia, Yinchuan, 750004, China; Key Laboratory of Fertility Preservation and Maintenance, Ningxia Medical University, Ministry of Education, Yinchuan, 750004, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Hong
authors.forename: Ma
authors.initials: M
authors.lastname: Zhan-Bing
authors.forename: Shi
authors.initials: S
authors.lastname: Zhi-Yun
authors.forename: Song
authors.initials: S
authors.lastname: Xiao-Xia
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jun-Li
authors.forename: Huo
authors.initials: H
authors.lastname: Zheng-Hao
mesh_terms: D000328:Adult; D000886:Anthropometry; D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D007839:Functional Laterality; D006801:Humans; D008875:Middle Aged; D012307:Risk Factors