BACKGROUND AND PURPOSE: To report the long-term biochemical control of a non-randomized trial comparing standard (STD) and hyper-fractionated (HFX) radiation schedules for prostate cancer treatment. MATERIALS AND METHODS: Between 1993 and 2003, 370 patients entered the study; 330/370 (STD: 179; HFX: 151) were evaluable for current analysis. Median doses were 79.2 Gy and 74 Gy for HFX (1.2 Gy/fr, two daily fractions) and STD (2 Gy/fr), respectively; median follow-up was 7.5 yr. The two regimens were compared in terms of biochemical relapse-free survival (according to ASTRO definition, bRFS) by univariate (log-rank test) and multivariate analyses (Cox regression hazard model). Based on published relationships between EQD2 and 5-yr biochemical control, α/β values for each subgroup could be estimated. RESULTS: 7.5 yr bRFS were 53.4% (± 4.4%, 95% CI) and 65.4% (± 4.0%) for HFX and STD, respectively (p=0.13); HFX was associated with a poorer outcome in NCCN low+intermediate patients (7.5 yr bRFS: 56.6% vs 73.5%, p=0.048) while no differences were seen for high-risk patients (7.5 yr bRFS: 44.1% vs 45.3%). Multivariate analysis revealed that NCCN risk grouping (high vs low+intermediate; OR: 0.59, p=0.009) and age (< vs ≥ 70 yr; OR: 0.67, p=0.03) were the main predictors of worse bRFS. In the subgroups of low+intermediate-risk patients < 70 yr, the poorer outcome of HFX was more evident (7.5 yr bRFS: 47.1% vs 70.9%, p=0.078) while no difference was seen for older patients (7.5 yr bRFS: 69.4% vs 72.0%, p=0.76). Our α/β estimates differ between low+intermediate-risk and high-risk patients. CONCLUSIONS: The bRFS long-term results of this non-randomized trial are consistent with different sensitivities to fractionation depending on NCCN risk grouping. The impact of age on the outcome of HFX for younger low+intermediate patients is consistent with an incomplete repair effect in older patients.
Long-term biochemical control of prostate cancer after standard or hyper-fractionation : evidence for different outcomes between low-intermediate and high risk patients / R. Valdagni, A. Nahum, T. Magnani, C. Italia, A. Lanceni, P. Montanaro, T. Rancati, B. Avuzzi, C. Fiorino. - In: RADIOTHERAPY AND ONCOLOGY. - ISSN 0167-8140. - 101:3(2011 Dec), pp. 454-459.
|Titolo:||Long-term biochemical control of prostate cancer after standard or hyper-fractionation : evidence for different outcomes between low-intermediate and high risk patients|
|Parole Chiave:||α/β; Conformal radiotherapy; Hyperfractionation; Prostate cancer; Oncology; Radiology, Nuclear Medicine and Imaging; Hematology|
|Settore Scientifico Disciplinare:||Settore MED/36 - Diagnostica per Immagini e Radioterapia|
|Data di pubblicazione:||dic-2011|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.radonc.2011.07.017|
|Appare nelle tipologie:||01 - Articolo su periodico|