Fluorescence in situ hybridization analysis of c-myc amplification in stage TNM prostate cancer in Japanese patients

Int J Urol. 2006 Jun;13(6):761-6. doi: 10.1111/j.1442-2042.2006.01399.x.

Abstract

Objective: Genetic aberration such as the amplification of c-myc has been commonly found in advanced prostate cancer. The aim of this study was to elucidate chromosome 8 alteration, including a gain and amplification of 8q24 (c-myc gene), related to the progression and survival in advanced (Stage C) prostate cancer.

Materials and methods: We used dual-probe fluorescence in situ hybridization with a centromere-specific probe for chromosome 8 (8cen), and with a region-specific probe for c-myc (8q24) to evaluate genetic changes in tumor samples from 50 patients who had undergone radical retropubic prostatectomy from 1986 to 2001.

Results: We classified the 8cen and c-myc copy numbers as normal, gain and amplification. The carcinoma foci with extra copies of c-myc, which was defined in 35 cases (70%), were divided into two groups: (a) a simple gain of the whole chromosome 8 (no increase in the c-myc copy number relative to the chromosome 8 centromere), which was identified in 15 cases (30%); and (b) a substantial amplification of c-myc (additional increases [AI] in the c-myc copy number relative to the chromosome 8 centromere), which was detected in 20 cases (40%). AI-c-myc was strongly associated with higher histopathological grades and Gleason's scores (P = 0.0330, 0.0190, respectively). Patients with the AI-c-myc had earlier disease progression (P = 0.0029) and earlier cancer death (P = 0.0087) than did patients with normal patterns.

Conclusion: Identification of an AI-c-myc may serve as a potential marker of prostate cancer progression.

MeSH terms

  • Aged
  • Biomarkers, Tumor / genetics*
  • Chromosome Aberrations
  • Chromosomes, Human, Pair 8 / genetics
  • Disease Progression
  • Gene Amplification*
  • Gene Dosage*
  • Humans
  • In Situ Hybridization, Fluorescence / methods
  • Male
  • Middle Aged
  • Neoplasm Staging / methods
  • Prostatectomy
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / therapy
  • Proto-Oncogene Proteins c-myc / genetics*
  • Retrospective Studies

Substances

  • Biomarkers, Tumor
  • Proto-Oncogene Proteins c-myc