title: Re-evaluating the biological significance of seminal vesicle invasion (SVI) in locally advanced prostate cancer.
abstract: OBJECTIVE
  • To examine the impact of seminal vesicle invasion (SVI) in patients with locally advanced (pT3) prostate cancer on clinical outcome. • To explore the clinical association of SVI with metastatic disease. • To distinguish between the possibilities that either seminal vesicles possess their own biological significance and represent a privileged staging site for systemic tumour cell dissemination, or that their invasion is a surrogate marker for an aggressive large-volume poorly differentiated cancer.
  
  
  METHODS
  • Patients with extraprostatic extension (EPE) and/or SVI were identified from a prospectively recorded and maintained prostate cancer database. • Patients were categorised according to the presence of SVI as determined by routine pathological assessment. Tumour volumes were measured routinely by computed planimetry at the time of histological assessment. • The impact of SVI on biochemical recurrence with a definition of a prostate-specific antigen (PSA) level of ≥0.2 ng/mL, as well as a clinically significant recurrence defined as failure with a PSA doubling time of <6 months, was determined by univariable and multivariable Cox regression analysis.
  
  
  RESULTS
  • Of 249 patients with pT3 disease, 46 (18%) had SVI, 40 (87%) by direct extension and six (13%) metastatic. • Tumours with SVI had significantly greater tumour burden as determined by total tumour volume (7.2 vs 3.7 mL, P < 0.001), index tumour volume (6.8 vs. 3.4 mL, P < 0.001) and percentage tumour volume (21.8 vs 12.4 %, P= 0.001). • After controlling for tumour volume and Gleason score, the presence of SVI did not significantly predict for the development of a significant PSA recurrence.
  
  
  CONCLUSIONS
  • Our results suggest that SVI is a surrogate marker of larger and more aggressive tumours with higher Gleason scores rather than a privileged site of tumour cell dissemination.
authors.affiliation: Department of Surgery, University of Melbourne, Royal Melbourne Hospital, Parkville, VIC, Australia. sapni973@gmail.com
authors.forename: Nikhil
authors.initials: N
authors.lastname: Sapre
authors.forename: John
authors.initials: J
authors.lastname: Pedersen
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Hong
authors.forename: Laurence
authors.initials: L
authors.lastname: Harewood
authors.forename: Justin
authors.initials: J
authors.lastname: Peters
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Costello
authors.forename: Chris M
authors.initials: CM
authors.lastname: Hovens
authors.forename: Niall M
authors.initials: NM
authors.lastname: Corcoran
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000401:mortality / Q000473:pathology*; D012669:Seminal Vesicles / Q000473:pathology*; D015996:Survival Rate / Q000639:trends; D013736:Testicular Neoplasms / Q000097:blood / Q000453:epidemiology / Q000473:pathology*; D014739:Victoria / Q000453:epidemiology
chemical_list: D017430:Prostate-Specific Antigen