Mutation detection in formalin-fixed prostate cancer biopsies taken at the time of diagnosis using next-generation DNA sequencing

J Clin Pathol. 2015 Mar;68(3):212-7. doi: 10.1136/jclinpath-2014-202754. Epub 2015 Jan 13.

Abstract

Aims: Assessing whether next-generation DNA sequencing (NGS) can be used to screen prostate cancer for multiple gene alterations in men routinely diagnosed with this disease and/or who are entered into clinical trials. Previous studies are limited and have reported only low success rates.

Methods: We marked areas of cancer on H&E-stained sections from formalin-fixed needle biopsies, and used these as templates to dissect cancer-rich tissue from adjacent unstained sections. DNA was prepared using a Qiagen protocol modified to maximise DNA yield. The DNA was screened simultaneously for mutations in 365 cancer-related genes using an Illumina HiSeq 2000 NGS platform.

Results: From 63 prostate cancers examined, 59(94%) of the samples yielded at least 30 ng of DNA, the minimum amount of DNA considered suitable for NGS analysis. Patients in the D'Amico high-risk group yielded an average of 1033 ng, intermediate-risk patients 401 ng, and low-risk patients 97 ng. NGS of eight samples selected from high-risk and intermediate-risk groups gave a median exon read depth of 962 and detected TMPRRS2-ERG fusions, as well as a variety of mutations including those in the SPOP, TP53, ATM, MEN1, NBPF10, NCOR2, PIK3CB and MAP2K5 (MEK5) genes.

Conclusions: Using the methods presented here, NGS technologies can be used to screen a high proportion of patients with prostate cancer for mutations in cancer-related genes in tissue samples opening up its general use in the context of clinical trials or routine diagnosis.

Keywords: CANCER; CANCER GENETICS; GENETICS; MOLECULAR GENETICS; PROSTATE.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers, Tumor / blood
  • Biomarkers, Tumor / genetics*
  • Biopsy, Fine-Needle
  • DNA Mutational Analysis / methods*
  • Fixatives*
  • Formaldehyde*
  • Genetic Predisposition to Disease
  • Genetic Testing / methods*
  • High-Throughput Nucleotide Sequencing*
  • Humans
  • Kallikreins / blood
  • Male
  • Middle Aged
  • Mutation*
  • Neoplasm Grading
  • Neoplasm Staging
  • Phenotype
  • Predictive Value of Tests
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / pathology
  • Risk Assessment
  • Risk Factors
  • Tissue Fixation / methods*

Substances

  • Biomarkers, Tumor
  • Fixatives
  • Formaldehyde
  • KLK3 protein, human
  • Kallikreins
  • Prostate-Specific Antigen