By Reuters Staff
NEW YORK (Reuters Health) - 5/8/2019
Elective nodal radiotherapy (ENRT) appears to reduce relapses better than stereotactic body radiotherapy (SBRT) in men with nodal oligorecurrent prostate cancer, according to a retrospective analysis.
But ENRT is also more toxic, researchers report in European Urology, online July 19.
Following local therapy of prostate cancer, the most dominant sites of recurrence are lymph nodes, which can be targeted with focal SBRT or more comprehensively with ENRT. It remains unclear which of the treatments is better.
Dr. Elise De Bleser from Ghent University Hospital, in Belgium, and colleagues from 15 different centers reviewed differences in toxicity and efficacy between 309 men receiving SBRT and 197 receiving ENRT for oligorecurrent nodal prostate cancer.
The three-year metastasis-free survival (MFS) was 68% after SBRT and 77% after ENRT (P=0.01). In multivariable analysis, ENRT resulted in significantly longer MFS than SBRT among men presenting with only one node at recurrence, but not among those presenting with more than one lymph node.
Local progression was seen in 50 men following SBRT versus only nine men following ENRT (P<0.001).
The three-year castration-resistant prostate cancer (CRPC)-free survival did not differ significantly between the treatment groups. During a median of 34 months of follow-up, 419 men remained free of CRPC.
There was no early or late grade-3-or-higher toxicity following SBRT, but there were five such events following ENRT. Early toxicity was significantly greater following ENRT (three cases after SBRT versus 12 cases after ENRT) as was late toxicity (16 cases after SBRT and 31 cases after ENRT).
"Our findings hypothesize that ENRT should be preferred to SBRT in the treatment of nodal oligorecurrences," the researchers conclude. "This hypothesis needs to be evaluated in a randomized trial."
Dr. De Bleser did not respond to a request for comments.
Eur Urol 19 2019.