title: Utility of circulating B-RAF DNA mutation in serum for monitoring melanoma patients receiving biochemotherapy.
abstract: OBJECTIVE
  Somatic B-RAF gene mutation has been identified in many malignancies and detected at a high frequency in cutaneous malignant melanoma. However, the significance of the B-RAF mutation (B-RAFmt) in terms of its prognostic and predictive capabilities for treatment response or disease outcome is not known. We hypothesized that circulating serum B-RAFmt (B-RAFsmt) at V600E, detected in serum, predicts response in melanoma patients receiving concurrent biochemotherapy.
  
  
  METHODS
  A real-time clamp quantitative reverse transcription-PCR assay was designed to assess B-RAFsmt by peptide nucleic acid clamping and a locked nucleic acid hybrid probe. Normal (n = 18) and American Joint Committee on Cancer stage I to IV melanoma patients (n = 103) were evaluated. These included stage IV patients (n = 48) with blood drawn before and after biochemotherapy. Patients were classified as biochemotherapy responders or nonresponders. Responders (n = 24) had a complete or partial response following biochemotherapy; nonresponders (n = 24) developed progressive disease.
  
  
  RESULTS
  Of the 103 melanoma patients, 38 (37%) had B-RAFsmt DNA, of which 11 of 34 (32%) were stage I or II, and 27 of 69 (39%) were stage III or IV. Of the 48 biochemotherapy patients, 10 of 24 (42%) patients were positive for the B-RAFsmt in the respective responder and nonresponder groups before treatment. After biochemotherapy, B-RAFsmt was detected in only 1 of 10 patients (10%) in the responder group and 7 of 10 patients (70%) in the nonresponder group. B-RAFsmt is associated with significantly worse (P = 0.039) overall survival in patients receiving biochemotherapy.
  
  
  CONCLUSIONS
  These studies show the presence and utility of circulating B-RAFsmt DNA in melanoma patients.
authors.affiliation: Department of Molecular Oncology, Division of Surgical Oncology, John Wayne Cancer Institute at Saint John's Health Center and The Angeles Clinic and Research Institute, Santa Monica, California 90404, USA.
authors.forename: Masaru
authors.initials: M
authors.lastname: Shinozaki
authors.forename: Steven J
authors.initials: SJ
authors.lastname: O'Day
authors.forename: Minoru
authors.initials: M
authors.lastname: Kitago
authors.forename: Farin
authors.initials: F
authors.lastname: Amersi
authors.forename: Christine
authors.initials: C
authors.lastname: Kuo
authors.forename: Joseph
authors.initials: J
authors.lastname: Kim
authors.forename: He-Jing
authors.initials: HJ
authors.lastname: Wang
authors.forename: Dave S B
authors.initials: DS
authors.lastname: Hoon
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D015342:DNA Probes; D004273:DNA, Neoplasm / Q000097:blood*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008545:Melanoma / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D008875:Middle Aged; D009154:Mutation; D011237:Predictive Value of Tests; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D015342:DNA Probes; D004273:DNA, Neoplasm; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf