title: Methylated DNA and total DNA in serum detected by one-step methylation-specific PCR is predictive of poor prognosis for breast cancer patients.
abstract: OBJECTIVE
  We recently developed the one-step methylation-specific PCR (OS-MSP) assay which can detect methylated DNA (met-DNA) in serum with high sensitivity. To examine its prognostic value, we applied this new assay to the detection of met-DNA in serum of breast cancer patients.
  
  
  METHODS
  Serum samples taken before surgery from 336 primary invasive breast cancer patients were subjected to the OS-MSP assay for the promoter regions of GSTP1, RASSF1A, and RARβ2. The assay outcome was considered positive when methylation was detected in at least one of these three genes. Total DNA content in serum was also determined.
  
  
  RESULTS
  Of the 336 stage I/II patients, 33 (10%) were positive for met-DNA in serum and showed a significantly worse overall survival (OS) rate at 100 months (78 vs. 95%; p = 0.002) than those with negative findings (n = 303). Patients with high total DNA in serum (n = 112) also showed a significantly worse OS rate at 100 months (86 vs. 97%; p = 0.001) than those with low total DNA in serum (n = 224). Moreover, patients both positive for met-DNA and with high total DNA in serum (n = 18) showed a much worse OS rate at 100 months (65 vs. 94%; p < 0.001) than the others (n = 318).
  
  
  CONCLUSIONS
  Met-DNA in serum detected with the OS-MSP assay constitutes a significant and independent prognostic factor, and its combination with total DNA in serum seems to be even more effective for prediction of prognosis for breast cancer patients.
authors.affiliation: Department of Breast and Endocrine Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Fujita
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakayama
authors.forename: Noriaki
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Seung Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Kenzo
authors.initials: K
authors.lastname: Shimazu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shimomura
authors.forename: Naomi
authors.initials: N
authors.lastname: Maruyama
authors.forename: Koji
authors.initials: K
authors.lastname: Morimoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tamaki
authors.forename: Shinzaburo
authors.initials: S
authors.lastname: Noguchi
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D019175:DNA Methylation; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000097:blood*; D005260:Female; D051549:Glutathione S-Transferase pi / Q000235:genetics; D006801:Humans; D008207:Lymphatic Metastasis; D008408:Mastectomy / Q000379:methods; D008875:Middle Aged; D008969:Molecular Sequence Data; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D011401:Promoter Regions, Genetic; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D018168:Receptors, Retinoic Acid / Q000235:genetics; D012189:Retrospective Studies; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D017931:DNA Primers; D004273:DNA, Neoplasm; D051549:Glutathione S-Transferase pi; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D018168:Receptors, Retinoic Acid; D025521:Tumor Suppressor Proteins; C411762:RASSF1 protein, human; C540966:retinoic acid receptor, beta2, human; C496556:GSTP1 protein, human; C508053:ERBB2 protein, human