Abstract
<div>Abstract<p><b>Purpose:</b> We previously reported that protein kinase A type I (PKA<sub>RIα</sub>) overexpression was predictive of outcome in prostate cancer patients treated with radiotherapy (RT) ± short-term androgen deprivation (STAD) on Radiation Therapy Oncology Group (RTOG) protocol 86-10. Here, we attempt to verify our prior findings and test the hypothesis that the relationship of the length of AD to patient outcome is affected by PKA<sub>RIα</sub> overexpression.</p><p><b>Experimental Design:</b> There were 313 cases in the RTOG 92-02 study cohort with available tissue and suitable staining by immunohistochemistry. Median follow-up was 10.1 years. The intensity of PKA<sub>RIα</sub> staining intensity was quantified manually and by image analysis. Multivariate analyses were done for overall mortality using Cox proportional hazards models and for local failure, biochemical failure, distant metastasis, and cause-specific mortality using Fine and Gray's regression models.</p><p><b>Results:</b> The expression levels of PKA<sub>RIα</sub>, determined by manual and image analysis, were strongly correlated (<i>P</i> < 0.0001). In the multivariate analyses, manual-quantified and image analysis–quantified PKA<sub>RIα</sub> staining intensities were independent predictors of distant metastasis (<i>P</i> < 0.01), local failure (<i>P</i> < 0.05), and biochemical failure (<i>P</i> ≤ 0.01). Furthermore, the benefit of long-term AD over STAD was much less when PKA<sub>RIα</sub> expression was high.</p><p><b>Conclusions:</b> PKA<sub>RIα</sub> overexpression has been shown in two RTOG trials to be associated with an increased risk of failure after AD + RT. In this series of contemporary high-risk patients, PKA<sub>RIα</sub> overexpression was associated with diminished response to LTAD + RT relative to STAD + RT, suggesting that such patients would be ideal for a PKA<sub>RIα</sub> knockdown strategy. (Clin Cancer Res 2009;15(17):5478–84)</p></div>
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
