title: Telomere length in breast cancer patients before and after chemotherapy with or without stem cell transplantation.
abstract: High-dose chemotherapy and peripheral blood stem cell transplantation (PBSCT) may accelerate telomere length loss in haematopoietic stem cells. As data including pre-and post-treatment samples are lacking, we studied leukocyte telomere length and telomerase activity before and after treatment in breast cancer patients randomized to receive 5 adjuvant courses FEC (5-FU, epirubicin and cyclophosphamide) (n = 17), or 4 x FEC followed by high-dose cyclophosphamide, thiotepa, carboplatin and autologous PBSCT (n = 16). Haemoglobin, MCV, leukocyte-and platelet numbers were assessed prior to (t(0)), 5 months after (t(1)) and 9 months after chemotherapy (t(2)); these parameters were decreased at t(1)and t(2)compared to t(0)(high-dose: all parameters; standard-dose: leukocytes and platelets), and all parameters were lower after high-dose than standard-dose treatment at t(1). Paired individual leukocyte samples of t(0)and t(1)showed telomere length change (determined by telomere restricted fragment (TRF) assay) ranging from +0.8 to -2.2 kb, with a decreased TRF length in 9 patients of both groups. Telomerase activity (determined by TRAP assay) was below detection limit in leukocyte samples of t(0)and t(1). Thus, standard-and high-dose chemotherapy negatively affect haematological reconstitution in this setting. In individual patients, telomere length can be remarkably changed following haematological proliferative stress after treatment.
authors.affiliation: Department of Medical Oncology, University Hospital Groningen, The Netherlands.
authors.forename: C P
authors.initials: CP
authors.lastname: Schröder
authors.forename: G B
authors.initials: GB
authors.lastname: Wisman
authors.forename: S
authors.initials: S
authors.lastname: de Jong
authors.forename: W T
authors.initials: WT
authors.lastname: van der Graaf
authors.forename: M H
authors.initials: MH
authors.lastname: Ruiters
authors.forename: N H
authors.initials: NH
authors.lastname: Mulder
authors.forename: L F
authors.initials: LF
authors.lastname: de Leij
authors.forename: A G
authors.initials: AG
authors.lastname: van der Zee
authors.forename: E G
authors.initials: EG
authors.lastname: de Vries
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D016190:Carboplatin / Q000008:administration & dosage; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D003520:Cyclophosphamide / Q000008:administration & dosage; D015251:Epirubicin / Q000008:administration & dosage; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007962:Leukocytes / Q000201:enzymology / Q000473:pathology; D008207:Lymphatic Metastasis; D008875:Middle Aged; D010976:Platelet Count; D011994:Recombinant Proteins; D019098:Telomerase / Q000097:blood*; D016615:Telomere / Q000473:pathology*; D013852:Thiotepa / Q000008:administration & dosage
chemical_list: D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D015251:Epirubicin; D003520:Cyclophosphamide; D013852:Thiotepa; D016190:Carboplatin; D019098:Telomerase; D005472:Fluorouracil