Differential expression of cancer-related proteins in paired breast milk samples from women with breast cancer

J Hum Lact. 2012 Nov;28(4):543-6. doi: 10.1177/0890334412453205. Epub 2012 Aug 20.


Background: Breast cancer risk increases during pregnancy and remains elevated for a number of years thereafter. Cancer-associated proteins that are secreted into breast milk may provide a means to detect cancer in the lactating breast or to assess future breast cancer risk.

Objective: To determine whether proteins linked to breast cancer would be differentially expressed in matched (both breasts from each participant) human milk samples collected from women with unilateral breast cancer.

Methods: Five cancer-associated proteins (basic fibroblast growth factor [bFGF], YKL-40, neutrophil gelatinase-associated lipocalin, and transforming growth factor β1 and β2) were analyzed in milk provided by 5 lactating women, 4 of whom were known to have cancer in 1 breast (and the opposite breast clinically disease free) at the time of milk collection and 1 who developed breast cancer 2 years after milk collection.

Results: Expression was significantly higher for TGFβ2 (P = .03) and bFGF (P =.03) in the breasts with cancer.

Conclusion: These proteins may play a role in assessing a woman's risk of pregnancy-associated breast cancer. Because of variable protein concentration among patients and the limited sample size, the results are considered preliminary.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Proteins / metabolism
  • Adipokines / metabolism
  • Adult
  • Biomarkers, Tumor / metabolism*
  • Breast Neoplasms / metabolism*
  • Carcinoma, Ductal, Breast / metabolism*
  • Carcinoma, Intraductal, Noninfiltrating / metabolism*
  • Case-Control Studies
  • Chitinase-3-Like Protein 1
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Fibroblast Growth Factor 2 / metabolism
  • Humans
  • Lactation / metabolism*
  • Lectins / metabolism
  • Lipocalin-2
  • Lipocalins / metabolism
  • Milk, Human / metabolism*
  • Proto-Oncogene Proteins / metabolism
  • Risk Assessment
  • Transforming Growth Factor beta1 / metabolism
  • Transforming Growth Factor beta2 / metabolism


  • Acute-Phase Proteins
  • Adipokines
  • Biomarkers, Tumor
  • CHI3L1 protein, human
  • Chitinase-3-Like Protein 1
  • LCN2 protein, human
  • Lectins
  • Lipocalin-2
  • Lipocalins
  • Proto-Oncogene Proteins
  • Transforming Growth Factor beta1
  • Transforming Growth Factor beta2
  • Fibroblast Growth Factor 2