Dr. Tomlins started his talk by noting that the primary goal of translational pathology labs is to improve the lives of patients with cancer. Current prostate cancer tissue based prognostic tests, Dr Tomlins points out, are all designed to assess gene expression, whether the test is Prolaris assessing known pathways dysregulated in progression, or Decipher which measures 1.2 million expressed transcripts. Importantly, these all depend on the profile from one area of the tumor, giving the same output even if there is a second, distinct lesion. In Dr. Tomlins opinion, this leads to two questions: (i) Does prostate cancer progress? and (ii) What about the issue of multifocality?
With regards to the possibility of progression, Dr. Tomlins notes that this information is specifically important for patients on active surveillance (AS) protocols. In addition to incorporating a prostate MRI into the AS algorithm, with the biopsy core tissue, Dr. Tomlins argues that tissue from the biopsy core allows for the possibility for immunohistochemistry for ERG mutations, as well as RNA sequencing for additional markers. This information also allows for tracking ‘clonal’ mutations.
The second scenario that Dr. Tomlins is interested in is tumor multifocality. In the setting of evaluating multifocality, multiplex RNA sequencing (compared to real time-PCR) requires only a small amount of tissue (<1-10 ng) or urine RNA as compared to >>10ng of tissue necessary for qRT-PCR. Multiplex RNA sequencing also allows for digital data and combinatorial priming for gene fusions/splice variants. This rapid and efficient technology is particularly important when sequencing tissue from multifocal tumor locations.
In conclusion, Dr. Tomlins notes that technological advances are enabling widespread opportunities for precision medicine. Specifically, this allows utility of both comprehensive and targeted approaches, as well as integration of DNA (pan-cancer) and RNA (disease specific) information. Finally, Dr. Tomlins warns that it is important not to over-promise the impact of precision medicine in oncology as it is currently applied.
Presented by: Scott Tomlins, University of Michigan, Ann Arbor, MI, USA
Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA