title: Effects of tamoxifen and octreotide LAR on the IGF-system compared with tamoxifen monotherapy.
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.
authors.affiliation: Department of Medicine, Section of Oncology, Haukeland University Hospital, N-5021 Bergen, Norway.
authors.forename: S I
authors.initials: SI
authors.lastname: Helle
authors.forename: W
authors.initials: W
authors.lastname: Mietlowski
authors.forename: J P
authors.initials: JP
authors.lastname: Guastalla
authors.forename: I
authors.initials: I
authors.lastname: Szakolczai
authors.forename: E
authors.initials: E
authors.lastname: Bajetta
authors.forename: H
authors.initials: H
authors.lastname: Sommer
authors.forename: E
authors.initials: E
authors.lastname: Baltali
authors.forename: T
authors.initials: T
authors.lastname: Pinter
authors.forename: M
authors.initials: M
authors.lastname: Csepreghy
authors.forename: L
authors.initials: L
authors.lastname: Ottestad
authors.forename: C
authors.initials: C
authors.lastname: Boni
authors.forename: C
authors.initials: C
authors.lastname: Bryce
authors.forename: J G M
authors.initials: JG
authors.lastname: Klijn
authors.forename: P E
authors.initials: PE
authors.lastname: Lønning
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood / Q000187:drug effects*; D008875:Middle Aged; D015282:Octreotide / Q000008:administration & dosage; D016016:Proportional Hazards Models; D013002:Somatomedins / Q000032:analysis / Q000187:drug effects*; D013629:Tamoxifen / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D013629:Tamoxifen; D015282:Octreotide