title: Cytogenetic effects of neutron therapy in patients with parotid gland tumors and relapse of breast cancer.
abstract: OBJECTIVE
  To assess the frequency and spectrum of chromosome aberrations and micronuclei in peripheral blood lymphocytes of patients with parotid salivary gland tumors and relapse of breast cancer during the course of neutron therapy.
  
  
  METHODS
  Samples of peripheral blood were obtained from 9 patients with parotid salivary gland tumors (T3N0-3M0) and 8 patients with relapse of breast cancer before, after first fraction and at the end of neutron therapy. The treatment course specified 5.5-8.4 Gy (equivalent to 23-44 Gy of photon irradiation) with 1.3-2.2 Gy per fraction for patients with parotid salivary gland tumors and 4,8-8.0 Gy (equivalent to 30-40 Gy of photon irradiation) with 1.6 Gy per fraction for patients with relapse of breast cancer. Control group established for conventional cytogenetic analysis consisted of 15 healthy persons. Assessment of chromosome aberrations frequency was performed on routinely stained metaphase plates. Lymphocytes from the same patients were analyzed by micronucleus test in combination with fluorescent in situ hybridization (FISH) using pancentromeric DNA probe.
  
  
  RESULTS
  Level of chromosome aberrations and micronuclei significantly increased in lymphocytes of patients from both groups during neutron therapy (P < 0.05). This increase was mainly due to chromosome-type aberrations and centromere-negative micronuclei. The prevalent types of aberrations are in agreement with theoretical mechanisms of neutron effects on cells.
  
  
  CONCLUSIONS
  Cytogenetic effects of fast neutron therapy in lymphocytes of patients with parotid salivary gland tumors and relapse of breast cancer were observed. A positive dynamics of radiation-induced chromosomal damages formation during the course was denoted in lymphocytes of cancer patients in both groups.
authors.affiliation: Cancer Research Institute, Siberian Branch of the Russian Academy of Medical Sciences, Tomsk 634050, Russia. genetic87@sibmail.com
authors.forename: A A
authors.initials: AA
authors.lastname: Melnikov
authors.forename: S A
authors.initials: SA
authors.lastname: Vasilyev
authors.forename: L I
authors.initials: LI
authors.lastname: Musabaeva
authors.forename: V V
authors.initials: VV
authors.lastname: Velikaya
authors.forename: O V
authors.initials: OV
authors.lastname: Gribova
authors.forename: Zh A
authors.initials: ZhA
authors.lastname: Startseva
authors.forename: L N
authors.initials: LN
authors.lastname: Urazova
authors.forename: I N
authors.initials: IN
authors.lastname: Lebedev
authors.forename: E L
authors.initials: EL
authors.lastname: Choynzonov
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy*; D002869:Chromosome Aberrations / Q000528:radiation effects*; D020732:Cytogenetic Analysis; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D017247:Neutron Capture Therapy / Q000009:adverse effects*; D010307:Parotid Neoplasms / Q000532:radiotherapy*