2011
ASTRO Annual Meeting
MIAMI - Compared with watchful waiting, external beam radiotherapy
significantly reduced both distant and clinical progression in patients with
early localized prostate cancer, according to data from a late-breaking
clinical abstract presented here.
In 1986, Anders Widmark, MD, and colleagues began a randomized
trial to examine PFS and OS among 214 patients with early
localized prostate cancer who were assigned to external beam
radiotherapy (EBRT) or watchful waiting. From 1986 to 1993, radiotherapy was
given with four-field-box EBRT, 64 Gy/32 fractions with a 2 cm margin, and
4-field CRT 64-68 Gy with a 1.5 cm margin thereafter, according to Widmark, of
the departments of radiation sciences and oncology at Umea University in
Sweden. Hormonal treatment was given upon objective progression in both arms;
EBRT was administered in some patients in the watchful waiting group. The
primary endpoint was PFS and overall mortality.
Median follow-up was 16 years, during which time 74 patients in the
watchful waiting arm and 64 in the
EBRT arm died, resulting in an OS of 0.31 (95% CI, 0.22-0.42)
for the watchful waiting group and 0.35 (95% CI, 0.25-0.48) for the EBRT arm.
After 15 years, prostate-cancer-specific death occurred among 25 patients in
the watchful waiting group and 19 in the EBRT group, yielding
prostate-cancer-specific survival of 0.72 (95% CI, 0.63-0.83) for watchful
waiting and 0.79 (95% CI, 0.71-0.89) for EBRT.
Distant progression occurred in 31% of the watchful waiting arm and 17%
of the EBRT arm, yielding a 15-year recurrence-free survival rate of 0.66 (95%
CI, 0.57-0.77) for watchful waiting and 0.81 (95% CI, 0.74-0.90) for EBRT.
Both biochemical and local progression rates favored the EBRT arm:
Treatment change due to clinical progression occurred among 58% of those in the
watchful waiting arm and 29% in the EBRT arm. This yielded a 15-year
recurrence-free survival rate of 0.40 (95% CI, 0.31-0.51) in the watchful
waiting arm and 0.67 (95% CI, 0.58-0.78) in the EBRT arm.
"In this randomized trial of external beam radiotherapy vs. watchful
waiting for patients with localized prostate cancer, external beam radiotherapy
significantly reduced distant progression and prolonged PFS," Widmark said
during his presentation.
For more information:
- Widmark A. LB 1. Presented at: the 2011 ASTRO Annual Meeting; Oct.
2-6; Miami.
Disclosure: The researchers report no relevant financial
disclosures.
|
Oliver Sartor, MD
|
Patients placed on surveillance in the Widmark trial, starting in 1986,
are very different than patients enrolled on surveillance in the PSA era, thus
caution is warranted in interpreting these results.
- Oliver Sartor, MD
Medical Director, Tulane
Cancer Center;
Director, Prostate Cancer Program