title: Breastfeeding and prognostic markers in breast cancer.
abstract: BACKGROUND
  Several studies suggest that total breastfeeding time reduces breast cancer risk. The underlying mechanisms are unclear. Whether breastfeeding also affects the prognosis is not yet investigated. A number of tumour characteristics, i.e. histological type of cancer, grade, tumour size, Nottingham prognostic index, vascular invasion and DNA-ploidy, have been demonstrated to be of prognostic value.
  
  
  METHODS
  We have searched for a possible link between these prognostic markers and breastfeeding time, age at first child and number of children. 250 women treated for breast cancer have answered a questionnaire.
  
  
  RESULTS
  No significant interactions were found possibly with one exception, LVI vs. age at first child. We found, significant correlations between lobular cancer, and thereby also DNA-ploidy, and age at first childbirth.
  
  
  CONCLUSIONS
  We have found that lobular cancer (and thereby also diploid tumours) are connected, independently, to age at first childbirth and possibly also to number of children but no other correlations between reproductive data, breastfeeding included, and prognostic markers used in this study were found.
authors.affiliation: Dep. Medical and Health Sciences, University of Linköping, Sweden. margalj@ltkalmar.se
authors.forename: Margaretha
authors.initials: M
authors.lastname: Lööf-Johanson
authors.forename: Lars
authors.initials: L
authors.lastname: Brudin
authors.forename: Marie
authors.initials: M
authors.lastname: Sundquist
authors.forename: Sten
authors.initials: S
authors.lastname: Thorstenson
authors.forename: Carl Edvard
authors.initials: CE
authors.lastname: Rudebeck
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001942:Breast Feeding; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D018275:Carcinoma, Lobular / Q000175:diagnosis* / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D010298:Parity; D011379:Prognosis; D015983:Selection Bias; D011795:Surveys and Questionnaires; D013997:Time Factors