Abstract
Gleason <6 (G6) prostate cancer (PC) at radical prostatectomy (RP): Does a high-risk setting truly exist? A recursive partitioning analysis (RPA)
Journal of clinical oncology, Vol.34(2_suppl), pp.132-132
01/10/2016
DOI: 10.1200/jco.2016.34.2_suppl.132
Abstract
132
Background: G6PC is associated with low rates of PSA failure (bF) after primary treatment. The present study seeks to determine whether a "high-risk" subpopulation of G6PC with lower PSA relapse-free survival (bRFS) may be identified within a large population of men with mature follow-up who underwent RP for curative-intent. Methods: Patients were retrospectively identified for inclusion by cT1-2 PC with PSA <30 at diagnosis, managed by RP alone, with final pathology demonstrating G6PC. Exclusion criteria were: pT3b or pN1, pre- or post-RP (adjuvant) radiotherapy (RT) or hormone therapy, or PSA follow-up (<12 months). The Kaplan-Meier method was employed for survival probability estimation. RPA by conditional inference analysis was applied to identify variables associated with bF. Results: From 2003-2009, 284 patients were eligible for this analysis. The median age was 60 yrs (range, 44-76), 233 (82%) were T1c, and median PSA was 5.3 (92% <10 ng/dL). The median biopsy to RP interval was 50 days (11-410, with 97% <180 days). Eighty patients (28%) had a positive margin (M+). At a median follow-up of 92.6 months (16.9-160.9, with 45% followed >8 years), 32 patients (11%) had bF, with estimated 5/8yr bRFS rates of 91%/89%. Univariate analysis identified M+, EPE, detectable initial post-RP PSA (at <26wks post-RP), longer biopsy to RP interval, and smaller RP specimen volume as significantly associated with bF, with M+ and longer biopsy to RP interval significant at multivariate analysis. RPA identified only M+ as a stratification factor, with 5/8yr bRFS estimates of 79/74% for M+ vs. 96/95% for M-. No other factors permitted further substratification of risk. Of note, 7 of 12 patients who underwent salvage RT alone remained disease-free at last follow-up, including 7 of 8 whose highest pre-salvage RT PSA was <0.6. Conclusions: G6PC managed by RP alone is generally associated with high rates of bRFS; however, in the M+ setting, irrespective of other clinical factors, early bF rates >20% are observed. Adjuvant RT should be considered in G6PC M+ cases; however, close surveillance with early salvage RT may be a reasonable alternative.
Details
- Title: Subtitle
- Gleason <6 (G6) prostate cancer (PC) at radical prostatectomy (RP): Does a high-risk setting truly exist? A recursive partitioning analysis (RPA)
- Creators
- Mark C Smith - University of IowaJames Kyle Russo - Bismarck Cancer Ctr, Bismarck, NDChad Tracy - University of IowaDarrion Mitchell - University of Iowa Department of Radiation Oncology, Iowa City, IASarah Mott - Holden Comprehensive Cancer Center, Iowa City, IAJohn Michael Buatti - University of IowaJohn Morgan Watkins - University of Iowa, Iowa City, IA
- Resource Type
- Abstract
- Publication Details
- Journal of clinical oncology, Vol.34(2_suppl), pp.132-132
- DOI
- 10.1200/jco.2016.34.2_suppl.132
- ISSN
- 0732-183X
- eISSN
- 1527-7755
- Language
- English
- Date published
- 01/10/2016
- Academic Unit
- Neurosurgery; Radiology; Urology; Otolaryngology; Radiation Oncology
- Record Identifier
- 9984314284202771
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