The impact of perineural invasion on biochemical outcome after permanent prostate iodine-125 brachytherapy
Received 6 May 2009; received in revised form 24 September 2009; accepted 24 September 2009. published online 21 December 2009.
Abstract
Purpose
Perineural invasion (PNI) in prostate biopsies is associated with increased risk of higher Gleason score and worse pathologic stage. We report the influence of PNI in biochemical no evidence of disease (bNED) survival after 125I prostate brachytherapy (BT).
Methods and Materials
Pathology reports of 700 men with localized prostate cancer who underwent 125I prostate BT in 1999–2008 were reviewed. The presence or absence of PNI in the biopsy was documented in 339 men. Clinical, treatment, and dosimetric parameters, along with PNI status, were evaluated for bNED survival, defined by “nadir+2” definition.
Results
Of the 339 patients, 87% had favorable risk and 13% intermediate risk. PNI was present in 89 patients (26%). After a median followup of 32 months, there were five biochemical failures (4: +PNI and 1: −PNI), of which one was local failure (+PNI). Actuarial 5-year bNED survival for the entire group was 97.0% (92.9% for +PNI; 99.2% for −PNI). In univariate analysis age, pretreatment prostate-specific antigen, Gleason score 7, and intermediate risk group predicted for worse biochemical outcome, whereas the presence of PNI showed a trend toward significance (p=0.06). Some of the regression algorithms failed to converge because of low event rates.
Conclusions
We report excellent biochemical control in 339 men treated with 125I prostate BT. The presence of PNI showed a trend toward significance in predicting 5-year bNED survival but did not impact on local control and should not influence the decision to recommend BT for localized prostate cancer.
1Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
2Department of Radiation Medicine, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
3Department of Radiation Physics, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
4Department of Biostatistics, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
Corresponding author. British Columbia Cancer Agency, Center for the Southern Interior, Department of Radiation Oncology, 399 Royal Avenue, Kelowna, BC V1Y 5L3, Canada. Tel.: +250-712-3979; fax: +250-712-3911.
Financial disclosure/conflict of interest: Herewith, we, the authors, state clearly that there are no actual or potential conflicts of interest in the preparation of this manuscript.
Dr. Gómez-Iturriaga Piña was partially supported with unrestricted Fellowship funding by Core Oncology.
ABSTRACT