Earlier this year we reported the initial results of a truly randomized Canadian trial of cryotherapy vs. external beam radiation therapy (EBRT) for the treatment of localized prostate cancer. The same group of authors have now reported follow-up data on quality of life.
According to the new paper by Robinson et al., in this randomized trial, neither crotherapy nor EBRT showed a specific, long-term advantage with respect to post-treatment quality of life (QOL) – with one exception: men treated with cryoablation tended to have poorer sexual function over time than the men treated with EBRT. In the conclusion, the authors state clearly that, “Men who wish to increase their odds of retaining sexual function might be counseled to choose EBRT over cryoablation.”
In the original trial, conducted in Calgary, Alberta, between December 1997 and February 2003, 244 men with newly diagnosed localized prostate cancer were randomly assigned to be treated with cryoablation or EBRT, and all of the patients received neoadjuvant antiandrogen therapy. The patients were also asked to complete two validated surveys related to outcome and QOL on a predetermined schedule for up to 3 years post-treatment.
From a primary outcome point of view, the original trial showed that cryotherapy was “not inferior” to EBRT in terms of the patients’ disease progression and overall and disease-specific survival (although even the authors emphasized that these results had to be interpreted with great caution). The new report provides the following additional results:
- Regardless of treatment arm, participants reported relatively high levels of QOL, with few exceptions.
- Cryoablation was initially associated with significantly more acute urinary dysfunction, which resolved over time.
- No late arising QOL issues were observed.
- Both EBRT and cryoablation participants reported decreases in sexual function at 3 months post-treatment, with the cryoablation patients reporting poorer functioning.
- Mean sexual function score was 15 points lower at 3 years for the cryoablation group.
- Also at 3 years post-treatment, 13 percent more of the patients receiving cryoablation said that sexual function was a moderate or big problem.
Obviously, based on the data from this trial, cryotherapy is a viable option for the treatment of localized prostate cancer. However, it also appears clear that cryotherapy comes with greater risk than EBRT for effects on sexual function over time, as has long been suspected. The authors’ conclusion, stated above, would appear to be a very fair assessment of the situation.