What about seeding during prostate biopsy?BMJ 2012; 344 doi: https://doi.org/10.1136/bmj.e1029 (Published 14 February 2012) Cite this as: BMJ 2012;344:e1029
- G David Stainsby, retired orthopaedic surgeon1
Neither the study of the short term outcomes of prostate biopsy nor the accompanying editorial covers the potential of transrectal ultrasound guided (TRUS) prostate biopsy to cause needle track seeding and extracapsular extension of tumour.1 2
This was identified in 1991 and acknowledged in a 1997 Health Technology Assessment report.3 4 It noted that diagnosis of organ confined disease was unreliable, with about half of tumours upstaged after surgery. The report recommended investigating the consequences of increasing numbers of biopsies, particularly tumour seeding, and improving staging performance.
This research is yet to take place, and neither the ProtecT trial nor the ProBE study dealt with these recommendations.1
Djavan and Rocco concede that, “complications related to TRUS prostate biopsy are an integral part of the current discussion about prostate specific antigen screening and early detection, as well as the need for repeat and saturation biopsies.” However, they did not consider the procedure’s potential to cause local tumour spread.
Djavan and colleagues reported results of radical prostatectomy after clinical diagnosis of organ confined disease at initial and repeat biopsy (138 and 53 men, respectively).5 At histopathological examination 42% and 39.1% were upstaged, with the finding of extracapsular tumour extension; 23% and 18% had positive surgical margins. Inaccuracy of staging and inadequate tumour removal continue to be reported.6 The possibility that this is caused by tumour seeding and local spread outside the capsule at biopsy has still not been investigated.
Longer term outcomes of prostate cancer treatment will continue to be poor until the risks of multi-needle biopsies are properly assessed and the disease is accurately staged after the biopsy result is known—before management is planned.
Cite this as: BMJ 2012;344:e1029
Competing interests: GDS was investigated within ProtecT study.