Can Hypofractionated Radiotherapy Improve Prostate Cancer Control?
Posted: Wednesday, September 26, 2018
Dose-escalated moderately hypofractionated intensity-modulated radiation therapy may improve cancer control and reduce treatment duration compared with conventionally fractionated IMRT among men with localized prostate cancer, a study reported in the Journal of Clinical Oncology. Karen E. Hoffman, MD, MHSc, MPH, of The University of Texas MD Anderson Cancer Center, and colleagues noted that “the prostate cancer control curves began to separate after 5 years.”
The investigators randomly assigned 206 men with organ-confined prostate cancer to receive hypofractionated radiation therapy (n = 104) or conventionally fractionated radiation therapy (n = 102). In the trial, the authors defined treatment failure as prostate-specific antigen (PSA) failure or initiation of salvage therapy.
Fewer treatment failures were observed in patients treated with hypofractionated radiation therapy (n = 10) than in those treated with conventionally fractionated radiation therapy (n = 21; P = .036). Of the total 31 treatment failures, 28 were considered PSA failures. The cumulative incidence of failure at 5, 8, and 10 years was also lower with hypofractionated radiation therapy. Furthermore, the time to failure was evaluated in an intent-to-treat analysis, and men receiving hypofractionated radiation therapy were less likely to develop treatment failure than those receiving conventional fractionation. Overall survival was not significantly different between the two treatment groups, and no prostate cancer–related deaths occurred.
Although a nonsignificant increase in late grade 2 or 3 gastrointestinal toxicity was observed in the hypofractionated radiation therapy group compared with the conventionally fractionated group (12.6% vs. 5.0%; P = .08), the number of men who developed toxicity was small. The risk of rectal bleeding was decreased by reducing the proportion of the rectum receiving the high-dose radiation.