Researchers using cutting-edge diagnostic techniques demonstrated that repeat sampling of the same clonal focus of prostate cancer can be achieved over time using magnetic resonance imaging/ultrasound fusion biopsy (“fusion biopsy”). In addition, their findings strongly suggest that high-grade prostate cancer may arise clonally from a low-grade cancer.
Have you read: Data offer new insight on HIFU’s use in low-risk PCa
“Our study provides the first definitive evidence that serial biopsies can be obtained from the same prostate cancer clonal focus through fusion biopsy, and so it supports use of this technique for following men during active surveillance,” said Ganesh S. Palapattu, MD, of the University of Michigan, Ann Arbor.
“It also raises the provocative idea that not all Gleason 6 prostate cancers may be indolent. Our findings point to the need for further research focusing on better characterizing these ‘high-risk low-grade’ cancers. Ultimately, these are the ones we need to follow.”
Conducted as a collaboration between urologists at the University of Michigan and the University of California, Los Angeles, the study included 31 men (mean age, 65 years, mean PSA at diagnosis, 4.6 ng/mL) with low-volume, Gleason 6 prostate cancer who were enrolled in an active surveillance program. All men underwent an initial diagnostic MR/fusion biopsy with individual needle core tracking and had a follow-up fusion biopsy of the same region. The median time between biopsies was 12 months.
Clonality of the initial and follow-up biopsies was assessed using immunohistochemistry to assay ERG status. In addition, targeted RNA/DNA next-generation sequencing (NGS) was performed to identify common oncogenic mutations in routine formalin-fixed paraffin-embedded biopsy tissues.