A total of 104 studies were included in the review. The numbers of studies for each intervention were as follows:
neoadjuvant hormonal therapy, 17 (including 4 systematic reviews);
adjuvant hormonal therapy, 7 (including 1 systematic review);
hormonal monotherapy, 1;
brachytherapy, 24 (including 4 systematic reviews);
3D-CRT , 25;
intensity-modulated conformal radiotherapy, 4;
cryotherapy, 12;
high-intensity focused ultrasound, 8;
interstitial microwave thermal therapy, 1;
transperianal radiofrequency interstitial tumour ablation, 2;
laser photocoagulation, 1; and
gene therapy, 2.
Neoadjuvant hormonal therapy: there were 13 RCTs investigating this intervention. There was no evidence of benefit in terms of biochemical disease-free survival.
Adjuvant hormonal therapy: one RCT was identified. There was no evidence of benefit in terms of survival, but there was conflicting evidence that patients at higher risk might benefit.
Hormonal monotherapy: one uncontrolled study suggested a possible effect but there were too few data to draw any conclusions.
Brachytherapy: 2 RCTs were found, but otherwise mainly case series (13, each of more than 100 patients). There was some evidence of benefit over standard therapy in terms of biochemical disease-free survival, but only in lower risk patients. The evidence suggested that quality of life may be lower with brachytherapy.
3D-CRT: 4 RCTs were identified. 3D-CRT resulted in significantly fewer gastrointestinal complications than standard radiotherapy.
Intensity-modulated conformal radiotherapy: case series were found, the largest of which suggested that this therapy might reduce late gastrointestinal toxicity compared with 3D-CRT.
Cryotherapy: the evidence base consisted of several case series. The results indicated that this intervention was associated with high rates of impotence.
The lack of evidence for the following interventions precludes the drawing of any conclusions regarding their effectiveness: high-intensity focused ultrasound, interstitial microwave thermal therapy, transperianal radiofrequency interstitial tumour ablation, laser photocoagulation and gene therapy.