Similar Low Incidence of Bowel Symptoms With Hypofractionated vs Conventionally Fractionated Radiotherapy in Localized Prostate Cancer

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As reported by Wilkins et al in The Lancet Oncology, 2-year patient-reported outcomes in a UK phase III trial (CHHiP) substudy have shown a similar low incidence of bowel problems among patients with intermediate-risk localized prostate cancer receiving hypofractionated vs conventionally fractionated radiotherapy. Emma Hall, PhD, of The Institute of Cancer Research, is the corresponding author of The Lancet Oncology article.

Study Details

The CHHiP trial is an open-label noninferiority trial comparing radiotherapy at a standard fractionation schedule of 74 Gy in 37 fractions vs two hypofractionated schedules at 60 Gy in 20 fractions and 57 Gy in 19 fractions in patients with T1b–T3aN0M0 prostate cancer, risk of seminal vesicle of < 30%, and prostate-specific antigen < 30 ng/mL. A quality-of-life substudy was performed in a subgroup of 2,100 patients allocated to the 74-Gy (n = 696), 60-Gy (n = 698), and 57-Gy schedules (n = 706). The primary outcome measure of the substudy was overall “bowel bother” (ie, “how much of a problem have you had with your bowels?”) at 24 months.

Similar Outcomes

Of the 2,100 patients, preradiotherapy data were available for 79%, and 24-month data were available for 69%. For the 74 Gy/37 fraction, 60 Gy/20 fraction, and 57 Gy/19 fraction groups, there was no bowel problem at 24 months in 269 (66%) of 410, 266 (65%) of 411, and 282 (65%) of 437; very small bother was reported by 22%, 22%, and 21%, small bother was reported by 6%, 7%, and 9%, moderate bother was reported by 5%, 6%, and 5%, and severe bother was reported by < 1%, < 1%, and < 1% (P = .64 for trend for 74 Gy vs 60 Gy, P = .59 for trend for 74 Gy vs 57 Gy).

No significant differences between the groups were observed for UCLA Prostate Cancer Index domain scores; Expanded Prostate Cancer Index Composite domain summary scores; or health-related quality-of-life domain scores on Short Form (SF)-36, Functional Assessment of Cancer Therapy-Prostate, or SF-12 at 24 months.

The investigators concluded: “The incidence of patient-reported bowel symptoms was low and similar between patients in the 74 Gy control group and the hypofractionated groups up to 24 months after radiotherapy. If efficacy outcomes from CHHiP show noninferiority for hypofractionated treatments, these findings will add to the growing evidence for moderately hypofractionated radiotherapy schedules becoming the standard treatment for localized prostate cancer.”

The study was funded by Cancer Research UK, the Department of Health, and the National Institute for Health Research Cancer Research Network. ■

Wilkins A, et al: Lancet Oncol 16:1605-1616, 2015.