title: Predictive value of tumor Ki-67 expression in two randomized trials of adjuvant chemoendocrine therapy for node-negative breast cancer.
abstract: Several small studies have reported that having a high percentage of breast tumor cells that express the proliferation antigen Ki-67 (ie, a high Ki-67 labeling index) predicts better response to neoadjuvant chemotherapy. However, the predictive value of a high Ki-67 labeling index for response to adjuvant chemotherapy is unclear. To investigate whether Ki-67 labeling index predicts response to adjuvant chemoendocrine therapy, we assessed Ki-67 expression in tumor tissue from 1924 (70%) of 2732 patients who were enrolled in two randomized International Breast Cancer Study Group trials of adjuvant chemoendocrine therapy vs endocrine therapy alone for node-negative breast cancer. A high Ki-67 labeling index was associated with other factors that predict poor prognosis. Among the 1521 patients with endocrine-responsive tumors, a high Ki-67 labeling index was associated with worse disease-free survival but the Ki-67 labeling index did not predict the relative efficacy of chemoendocrine therapy compared with endocrine therapy alone. Thus, Ki-67 labeling index was an independent prognostic factor but was not predictive of better response to adjuvant chemotherapy in these studies.
authors.affiliation: Division of Pathology and Laboratory Medicine, European Institute of Oncology, University of Milan, Via Ripamoniti 435, Milan, Italy. giuseppe.viale@ieo.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Viale
authors.forename: Meredith M
authors.initials: MM
authors.lastname: Regan
authors.forename: Mauro G
authors.initials: MG
authors.lastname: Mastropasqua
authors.forename: Fausto
authors.initials: F
authors.lastname: Maffini
authors.forename: Eugenio
authors.initials: E
authors.lastname: Maiorano
authors.forename: Marco
authors.initials: M
authors.lastname: Colleoni
authors.forename: Karen N
authors.initials: KN
authors.lastname: Price
authors.forename: Rastko
authors.initials: R
authors.lastname: Golouh
authors.forename: Tiziana
authors.initials: T
authors.lastname: Perin
authors.forename: R W
authors.initials: RW
authors.lastname: Brown
authors.forename: Anikó
authors.initials: A
authors.lastname: Kovács
authors.forename: Komala
authors.initials: K
authors.lastname: Pillay
authors.forename: Christian
authors.initials: C
authors.lastname: Ohlschlegel
authors.forename: Barry A
authors.initials: BA
authors.lastname: Gusterson
authors.forename: Monica
authors.initials: M
authors.lastname: Castiglione-Gertsch
authors.forename: Richard D
authors.initials: RD
authors.lastname: Gelber
authors.forename: Aron
authors.initials: A
authors.lastname: Goldhirsch
authors.forename: Alan S
authors.initials: AS
authors.lastname: Coates
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000188:drug therapy* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D003520:Cyclophosphamide / Q000008:administration & dosage; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis*; D016015:Logistic Models; D008727:Methotrexate / Q000008:administration & dosage; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D011237:Predictive Value of Tests; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D013629:Tamoxifen / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D013629:Tamoxifen; D003520:Cyclophosphamide; D005472:Fluorouracil; D008727:Methotrexate