In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 32, No. 4_suppl ( 2014-02-01), p. 150-150
Abstract:
150 Background: Indicators such as prostate-specific antigen (PSA) nadir after the first on-treatment period (ONTP), off-phase interval duration and PSA doubling time (PSADT) were interpreted as potentially predictive, regarding outcomes of intermittent androgen deprivation (IAD). From actual PSA measurement data recorded on patients undergoing IAD during their off-treatment period (OFTP), we conducted a systematic analysis aimed at screening indicators and finely assessing their relevance as predictive candidates. Methods: Between 1992 and 2012, 727 patients with PC were selected for IAD at our institution. Three hundred ten patients had biochemical recurrence (BCR) after local treatment, 172 showed metastatic disease. ONTP consisted of three-month dose injections of gonadatropin-releasing hormone (GnRH) agonist combined with daily oral androgen receptor antagonist. OFTP was indicated when PSA was less than 4 ng/ml. Criteria for resumption of hormonal therapy were PSA more than 20 ng/ml or clinical symptoms. We tested two basic patterns of PSA behavior-exponential and power law (a 〈 1) and combinations of them, on 597 patients with at least one completed OFTP based on four visits or more (population of the study). Results: We identified 597 patients with a total of 1,573 OFTPs. Median follow-up was 12,2 months (3,0-132,6). Median age at initiation was 76,7 (56,7 to 88,5); 811 OFTPs (51,6%) fitted with a pure exponential (r=0,01), whereas the other part (48,4%) followed more complex patterns (power law or two-steps or linear pattern). Mean cancer specific survival duration was 77,4 months (13,5 to 179,8). 5- and 10-year PC survival rate were respectively of 89,3% and 65,2% (CI 95%). Conclusions: Some OFTPs do not present an exponential pattern behavior: logarithmic calculation of PSADT is not suitable. PSADT determination should be adapted to the nature of the OFTP pattern. Through identification and analysis of the different types of OFTP, it is expected to improve the forecast of clinical outcomes.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2014.32.4_suppl.150
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2014
detail.hit.zdb_id:
2005181-5
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