PURPOSE: Nowadays, advanced irradiation techniques make it possible to escalate safely the dose in prostate cancer.
We studied the effect of a higher dose on tumor control in a randomized trial with a median follow-up of 110months.
PATIENTS AND METHODS: Patients with T1b-T4N0 prostate cancer (n=664) were randomized between 78Gy and 68Gy. Primary endpoint was biochemical and/or clinical failure (BCF) according to the American Society for Therapeutic Radiology and Oncology (ASTRO) guidelines (3 consecutive rises), and to Phoenix (nadir plus 2μg/L). Secondary endpoints were clinical failure (CF), local failure (LF), prostate cancer death (PCD), and overall survival (OS). Explorative subgroup analyses were performed.
RESULTS: BCF rate (HR=0.8; 20% less events) and LF rate (HR=0.5; 50% less events) were significantly lower in the 78Gy arm (p< 0.05). CF, PCD and OS were similar in both arms. A significant heterogeneity of treatment effect was found for PSA cutoffs between 7 and 10μg/L.
CONCLUSION: We observed significantly less BCF and LF in the high-dose arm. This suggests improvement of the therapeutic ratio. However, we observed similar rates of CF and PCD at the current update. More follow-up is needed to investigate which patients benefit in terms of prolonged OS.
Written by:
Heemsbergen WD, Al-Mamgani A, Slot A, Dielwart MF, Lebesque JV. Are you the author?
Department of Radiation Oncology, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
Reference: Radiother Oncol. 2013 Nov 15. pii: S0167-8140(13)00518-5.
doi: 10.1016/j.radonc.2013.09.026
PubMed Abstract
PMID: 24246414
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