Chicago—Tissue-based prognostic biomarker assays for prostate cancer are not robust to tumor multifocality and heterogeneity, according to research presented at the American Society of Clinical Oncology annual meeting in Chicago.
This finding speaks to the need for further studies to enable better identification of the biologically dominant lesion in patients with multifocal disease and/or the development of better prognostic techniques, said first author Simpa S. Salami, MD, clinical lecturer and urologic oncology fellow, department of urology, University of Michigan, Ann Arbor, working with Ganesh Palapattu, MD, and co-authors.
“Our research challenges the claim that in men with multifocal prostate cancer, analysis of a single biopsy specimen using an expression-based prognostic test can accurately predict the overall biologic trajectory of the disease,” Dr. Salami told Urology Times.
“This is an important issue because an estimated 60% to 80% of patients with prostate cancer have multifocal disease.”
To determine whether commercially available tissue expression-based prognostic tests are robust to multifocality, Dr. Salami and colleagues analyzed and compared the genetic profiles of 67 biopsy-derived primary tumor foci and 17 lymph node metastasis foci. The samples were obtained from 14 patients with grade-discordant multifocal disease, of whom 10 had N1 disease.
They were submitted for high-depth, targeted DNA and RNA next-generation sequencing using a customized panel of markers encompassing those included in commercially available prognostic tests.