Nadir PSA is a strong predictor of treatment outcome in intermediate and high risk localized prostate cancer patients treated by definitive external beam radiotherapy and androgen deprivation

Abstract

BackgroundThe aim of this study is to investigate the effect of tumor characteristics and parameters of treatment response in predicting biochemical disease-free survival (BFS) for patients with intermediate or high risk prostate cancer treated by combined definitive external beam radiation therapy (EBRT) and androgen deprivation therapy (ADT).MethodsBetween June 1995 and January 2015, 375 patients with localized prostate cancer and a National Comprehensive Cancer Network (NCCN) intermediate or high risk categories were treated by definitive EBRT and ADT. Median duration of androgen blockade was 10 months (range: 3–36 months); Median radiation dose was 72 Gy (Range: 70–78 Gy). Median follow-up time was 5.8 years (range: 0.8–16.39 years). The main study endpoint was biochemical disease free survival (BFS).ResultsForty seven patients (12.5%) developed biochemical recurrence (BCR) during the observation period. Monovariate analysis identified baseline PSA (bPSA) (p = 0.024), T-stage (p = 0.001), Gleason’s score (GS) (p = 0.042), radiation dose (p = 0.045), PSA pre-radiation therapy (p = 0.048), and nadir PSA (nPSA), (p < 0.001) as significant variables affecting BCR. The receiver operating characteristic (ROC) curve identified a nPSA of 0.06 ng/ml as optimal cut-off value significantly predicting the patients’ risk of BCR (p < 0.001). Multivariate cox regression analysis revealed T-stage, GS, and nPSA as independent variable affecting BFS, while bPSA, age, and radiation dose were not.ConclusionNadir PSA at 0.06 is a strong independent predictor of BFS in patients with intermediate or high risk prostate cancer treated by definitive EBRT and ADT.

Analysis of Circulating Tumor Cells in Patients with Non-Metastatic High-Risk Prostate Cancer before and after Radiotherapy Using Three Different Enumeration Assays

“…The prognostic significance of patients’ age as an independent predictor of biochemical recurrence is still controversial. Some reports recognized advanced age as an indicator of poorer biochemical outcome [70], while others did not find any association in patients undergoing radical prostatectomy [71] or radiotherapy [72]. However, another study suggested that in high-risk younger patients, biochemical recurrence-free survival is poorer than in older patients [73].…”

Management of patients with high-risk and advanced prostate cancer in the Middle East: resource-stratified consensus recommendations

“…Investigators from The American University of Beirut Medical Center (AUBMC) have shown that nadir PSA at 0.06 ng/ml is a strong predictor of outcome in a cohort of patients with intermediate and high-risk localized prostate cancer [28].…”

Favorable prognosis of patients who received adjuvant androgen deprivation therapy after radiotherapy achieving undetectable levels of prostate-specific antigen in high- or very high-risk prostate cancer

“…A-ADT for more than 12 months after RT was associated with nadir PSA <0.2 ng/mL significantly more frequently than ADT for less than 12 months in high-risk patients (88% in A-ADT ≥12 months vs. 74% in A-ADT <12 months, p < 0.0001) [ 17 ]. It has been reported that a nadir PSA level of <0.06 ng/mL is a powerful prognostic factor for 5-year BCFFS for intermediate- and high-risk patients treated with RT and long-term A-ADT (96% vs. 74%, p < 0.001) [ 18 ]. Similarly, a nadir PSA value of <0.001 ng/mL affected 5-year BCFFS (99% vs. 82.8%, p < 0.001) in the current study.…”

“…that a nadir PSA level of <0.06 ng/mL is a powerful prognostic factor for 5-year BCFFS for intermediate-and high-risk patients treated with RT and long-term A-ADT (96% vs. 74%, p < 0.001) [18]. Similarly, a nadir PSA value of <0.001 ng/mL affected 5-year BCFFS (99% vs. 82.8%, p < 0.001) in the current study.…”