Dose‐escalated radiation therapy for intermediate‐risk prostate cancer

Abstract

BACKGROUND:Randomized trials supported the use of androgen deprivation therapy (ADT) with radiation therapy (RT) for intermediate‐risk prostate cancer. However, the value of concurrent ADT was less certain with dose‐escalated RT. Better methods of stratifying patients in this risk group may help select patients who are most likely to benefit.METHODS:A total of 238 men with intermediate‐risk (prostate specific antigen [PSA] 10‐20, Gleason 7, or stage T2b‐c) adenocarcinoma of the prostate were treated with external beam RT between 1989 and 2006. Patients had Gleason≤6 (39%) or 7 (61%) tumors; median PSA was 10.5 ng/mL. A median of 37.5% of biopsy cores were positive from a median of 9 biopsy cores sampled. The median RT dose was 74 Gy to the prostate. A total of 112 patients (47%) received neoadjuvant and concurrent ADT (median, 4 months). Median follow‐up period was 49 months.RESULTS:The freedom from biochemical failure (FFBF, nadir + 2 definition) was 93% at 3 years, 86% at 4 years, and 80% at 5 years. On univariate analysis, the only factor associated with FFBF was percentage of positive cores (PPC, P = .0340). The prognostic value of PPC≥50 was not evident in patients receiving ADT (FFBF at 4 years 90% vs 91%, P = .3015). For patients not receiving ADT, the impact of PPC≥50 (FFBF at 4 years 76% vs 93%, P = .0844) was more pronounced. On multivariate analysis, PPC (P = .0388) was significantly associated with FFBF, whereas Gleason sum, ADT, RT dose, PSA, and T‐stage were not.CONCLUSIONS:After dose‐escalated external beam RT, intermediate‐risk prostate cancer patients with PPC≥50 had the highest risk for biochemical failure and may be most likely to derive a benefit from ADT. Cancer 2009. © 2009 American Cancer Society.

Role of Positive Biopsy Core Ratio in Prostate Cancer Patients

“…Other studies have often examined the usefulness of PPC for each treatment strategy, and its usefulness in the overall population was unknown. Focusing on each treatment strategy concerning the function of PPC as a predictor of radiotherapy, we acknowledge the reports of increased biochemical recurrence rate (BCR) when PPC is 50-67% or higher and a decreased rate when PPC is 33-50% or lower, with many studies reporting a bene t of intermediate to high-risk [10][11][12][13][14][15] . Jiayi Huang et al showed that PPC was the best prognostic predictor of the appearance of distant metastases after radiotherapy compared to T stage, GS, and PSA.…”

“…PPC has been reported to be a bene cial prognostic factor after radical prostatectomy (RP) and radiation therapy [10][11][12][13][14][15][16][17][18][19][20] . However, treatment guidelines for androgen-deprivation therapy (ADT) have yet to be described, and there are few reports on the association between PPC and ADT 21 .…”