The expression of Ki-S1 and BCL-2 and the response to primary tamoxifen therapy in elderly patients with breast cancer

Breast Cancer Res Treat. 1997 Jun;44(2):123-33. doi: 10.1023/a:1005796915388.


Ki-S1, a marker of proliferation, and bcl-2, the gene product of which is an antagonist of apoptosis, have been measured in 51 ER-positive primary breast cancers before and during tamoxifen treatment and then related to clinical response. Both markers were detected in the majority of tumours before treatment and, quantitatively, initial expression of Bcl-2 protein, but not Ki-S1, was significantly related to the percentage reduction in tumour volume as assessed by ultrasound. Staining for both markers was lower in post treatment samples than in those taken prior to treatments, but concordant decreases in staining indices were seen in only 11 of the 51 tumours. The results demonstrate, using clinical material, that the response to tamoxifen may involve changes in proliferation and/or susceptibility to cell-death.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antigens, Neoplasm / metabolism*
  • Biopsy
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / metabolism*
  • DNA Topoisomerases, Type II
  • DNA-Binding Proteins
  • Humans
  • Immunohistochemistry
  • Middle Aged
  • Nuclear Proteins / metabolism*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Receptors, Estrogen / metabolism
  • Tamoxifen / pharmacology
  • Tamoxifen / therapeutic use*


  • Antigens, Neoplasm
  • DNA-Binding Proteins
  • Nuclear Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Receptors, Estrogen
  • Tamoxifen
  • DNA Topoisomerases, Type II