title: Young age, increased tumor proliferation and FOXM1 expression predict early metastatic relapse only for endocrine-dependent breast cancers.
abstract: It is unclear if earlier onset (<40 years) and greater proliferative capacity confer an equally poor prognosis to endocrine-dependent and endocrine-independent breast cancers. Available outcome (distant metastasis-free survival, DMFS) and expression microarray data from 621 adjuvant treatment-naïve, node-negative primary breast cancers were pooled for prognostic evaluation of age-at-diagnosis (< 40 years vs. ≥ 40 years) and tumor proliferative capacity relative to estrogen receptor status (n = 400 ER-positive, n = 221 ER-negative). Transcriptome measures of proliferative capacity included a proliferation score (PS) based on a 61-gene proliferation signature and the single gene surrogate, FOXM1. Kaplan-Meier analyses revealed no significant difference in DMFS between ER-positive and ER-negative cases >5 years after diagnosis. In contrast, younger age and higher proliferative capacity resulted in significantly more metastatic events cumulated over 15 years, but only in ER-positive breast cancers where positive correlations between age and proliferation were observed. While strongly correlated, FOXM1 and PS did not appear equivalent in relation to age and prognosis. The poor prognosis associated with breast cancer arising before age 40 or with higher proliferative capacity pertains only to endocrine-dependent (ER-positive) breast cancer, indicating that different biological processes drive the metastatic potential of ER-negative breast cancer.
authors.affiliation: Cancer and Developmental Therapeutics Program, Buck Institute for Age Research, 8001 Redwood Blvd., Novato, CA 94945, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Yau
authors.forename: Yixin
authors.initials: Y
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: John A
authors.initials: JA
authors.lastname: Foekens
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Benz
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000378:metabolism*; D049109:Cell Proliferation; D018572:Disease-Free Survival; D004703:Endocrine System; D005260:Female; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000378:metabolism; D012008:Recurrence
chemical_list: C107585:FOXM1 protein, human; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; D011960:Receptors, Estrogen