Prostate Biopsy Spreads Cancer Cells?
Dear OncoLink "Ask The Experts,"
A February 20, 2008 breaking news release entitled "Prostate Biopsy Spreads Prostate Cancer Cells" appeared in the Prostate/Prostate Cancer section on Medical News Today's web site. Is this news likely to revolutionize the way we diagnose and test for prostate cancer?
Richard Whittington, MD, Associate Professor of Radiation Oncology at the University of Pennsylvania School of Medicine, responds:
I looked at the website, medicalnewstoday.com, and the article is based on a press release from a clinic in Sarasota, Florida, where the author talks about "seeding" the needle track with tumor cells. The problem with this is that while seeding is well described in tumors of the lung, biliary tract and some other sites, there are fewer than 100 cases reported of this happening with prostate cancer.
Think about it: 225,000 cases/yr x 15 yrs of PSA screening and biopsy when needed, which means about 100 cases is a relatively small number. Most of the described cases of seeding involve neuroendocrine tumors of the prostate, which are <1% of prostate tumors and don't make PSA, so PSA levels are not elevated.
The other technologies "advertised" on this website are MRI spectroscopic-directed biopsies and high frequency focused ultrasound therapy (HIFU). Neither is an accepted or proven technique at this time, but are certainly potential areas for future study. Ultimately, given that seeding of prostate cancer by the biopsy needle track is not a widespread or common issue, any purported advantage of these techniques with respect to avoiding seeding is a moot point.