Effects of tamoxifen and octreotide LAR on the IGF-system compared with tamoxifen monotherapy

S. I. Helle, W. Mietlowski, J. P. Guastalla, I. Szakolczai, E. Bajetta, H. Sommer, E. Baltali, T. Pinter, M. Csepreghy, L. Ottestad, C. Boni, C. Bryce, J. G.M. Klijn, P. E. Lønning

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8 Citations (Scopus)

Abstract

The insulin-like growth factor (IGF)-system was evaluated in 150 breast cancer patients participating in a randomised phase III trial comparing octreotide pamoate and tamoxifen with tamoxifen + placebo. Alterations in the IGF-system in the two treatment arms and individual changes with respect to outcome were compared. Serum IGF-I and -II, free IGF-I, and insulin-like growth factor binding protein 1-3 (IGFBP1-3) were measured by radioimmmunoassay (RIA)/immunoradiometric assay (IRMA) and IGFBPs by Western ligand blots (WLB) before and during treatment. Combined treatment caused a higher increase in IGFBP-1 and larger suppression of total and free IGF-I, IGF-II, and IGFBP-3 (P < 0.01 for all), but less suppression of IGFBP-2 (P < 0.05) compared with tamoxifen monotherapy. An increase in IGFBP-2 ≥25% was associated with decreased progression-free survival (PFS) in the total patient population and combined treatment group. Similar response rates and time to progression in the treatment arms suggests moderate suppression of circulating IGF-I has no influence on clinical outcome.

Original languageEnglish
Pages (from-to)694-701
Number of pages8
JournalEuropean Journal of Cancer
Volume41
Issue number5
DOIs
Publication statusPublished - Mar 2005

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Keywords

  • Breast cancer
  • IGF-I
  • IGFBP-2
  • Octreotide
  • Tamoxifen

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this

Helle, S. I., Mietlowski, W., Guastalla, J. P., Szakolczai, I., Bajetta, E., Sommer, H., Baltali, E., Pinter, T., Csepreghy, M., Ottestad, L., Boni, C., Bryce, C., Klijn, J. G. M., & Lønning, P. E. (2005). Effects of tamoxifen and octreotide LAR on the IGF-system compared with tamoxifen monotherapy. European Journal of Cancer, 41(5), 694-701. https://doi.org/10.1016/j.ejca.2004.12.015